Fireworks Safety Manual By Bill Ofca
A Collection of Essays by Bill Ofca
REVIEW OF THE BASICS
A general review of basic safety considerations for fireworks makers is             perhaps overdue. The new-comer amateur or pro can especially benefit from the             safety facts of this pyro-chemical art and science. Years of hard earned             experience, mistakes, and tragedy should not be relearned in bits and pieces.             This only invites history to repeat its tragedies. Nor does space in AFN allow             an in-depth and fair study of this vast subject. However, a look at some basics             may inspire readers, with a thirst for more knowledge, and a desire for future             existence to do research and ask questions.
It must be borne in mind that any mixture of oxygen and fuel, under the right             conditions, may explode if it ignites. It must be also remembered that fireworks             mixtures are mixtures of chemically bound oxygen and fuels in solid form. It is             therefore the responsibility and duty of all fireworks makers, from the hobby             mixer to the industrialist pro, to take all steps to prevent accidental             ignition. The second most important duty is to limit exposure by preventative             means, should accidental ignition occur. This means limitation of quantities             being worked on, and isolation of all other quantities of explosives. It also             means to limit the number of workers on an operation to the bare minimum             required, and to isolate the operation from accidental propagation to all other             operations on the premises.
Almost all the ingredients used in fireworks compositions are used as finely             divided powders, which greatly increases their surface area in a given volume             and/or density. For example, a charcoal dust cloud in air explodes violently             when ignited. Therefore, all finely divided mixtures of materials should be             handled with care. This is especially important with finely divided metals,             which are hard enough to cause friction ignition. Finely divided metals present             a hazard to violent explosion when ignited, and are susceptible to ignition by             static electricity more easily than other mixtures due to their conductivity.             Steel tools must be avoided in grinding, mixing, charging, pressing, tamping,             ramming, or other similar loading operations. Steel tools create sparks when             struck. The almost as hard bronze, may be used for certain purposes, but the             much softer brass and lead are safer. Wood and aluminum tools, and mallets made             of rawhide are also non-sparking safe.
Potassium chlorate, in many ways one of the best fireworks ingredients, may             under certain conditions of temperature and acidity, slowly break down giving             chloric acid, or chlorine dioxide, both of which are more active oxidizing             agents than potassium chlorate itself. When this happens, potassium chlorate             mixtures are extremely hazardous, with disastrous results often occurring.             Sensitivity to heat, shock, friction and impact are greatly enhanced with ignition occurring, in some cases, as little as a flick of the fingernail.             Sulfates, sulfides, and sulfur itself may be slowly oxidized to form sulfuric             acid, which can then break down the potassium chlorate into dangerously active             chloric acid.
Places where plain mixing is done containing sulfur, (but no potassium             chlorate;), must be kept separate from the places where chlorates are mixed.             This separation also applies to personnel, clothing, tools, and utensils, which             should be thoroughly washed between operations. No chlorate should ever be used             with ammonium salts because of the probability of forming ammonium chlorate,             which violently explodes at the temperature of boiling water (212 degrees F).             All the oxidizing agents, when mixed with finely divided metals, should be             handled with extra care and respect.
Carbon, (in the form of charcoal, lampblack, or carbon black), potassium             nitrate, and sulfur mixtures, seem to be fairly safe to handle. Barium nitrate             also seems fairly safe when mixed with sulfur, carbons, or finely divided             metals. Finely powdered metals, in mixtures with barium and strontium nitrates             and potassium perchlorate, even when sulfur is present, appear to be fairly             stable mixtures. It is reported, the sensitivity of such mixtures is increased             by the addition of powdered charcoal. There is no doubt charcoal does indeed             speed-up the burning rate of some mixtures, and also lowers the surface ignition             temperature of certain mixtures. There is some evidence that mixtures containing             both potassium perchlorate and asphalt gums, cause the perchlorate to be changed             into the chlorate, with disastrous results during storage. Asphalt gums should             be avoided with perchlorates or chlorates because the asphalt gums contain             sulfur and sulfur acids, which break down the chlorates to chloric acid.
The smallest amounts as possible should be used when experimenting with new             compositions, as the slightest incident can turn a mixture into an explosion.
Magnesium metal powder should be avoided by the inexperienced pyrotechnician.             This metal must be treated with special coatings to avoid spontaneous combustion             before it can be safely mixed with oxidizers. Magnesium cannot form a protective             metal oxide layer on its surface as aluminum can.
Mixes of any type of aluminum powder, potassium nitrate and sodium oxalate,             with water, will often heat;-up, and can result in spontaneous combustion.             Atomized aluminum, because of its strong aluminum oxide outer layer, appears to             be far less reactive than other aluminum powders in mixtures known to react with             aluminum.
Titanium seems to be relatively safe in regard to spontaneous ignition, and             has not been reported to cause such problems. Finely divided titanium powder or             dust, is a fire and explosion hazard by itself, when dry. For this reason             titanium dust is packed wet (with water) in sealed drums for shipment. Titanium             dust has no useful purpose in fireworks due to its hazardous nature. However, in             granular form (sponge), it is used to make many beautiful sparking effects.             Titanium is an extremely hard metal, and as such, poses a friction;-ignition             hazard. It especially increases the sensitivity of mixtures containing chlorates             or perchlorates. Extra care must be exercised when ramming devices such as             whistles, gerbs, fountains, etc., that contain perchlorates and titanium.             Ramming of devices containing potassium or barium chlorate should never be attempted, especially if titanium is an ingredient.
During commercial manufacturing, the amount of chemical composition in a             building at any one time should be kept as low as possible. The workers should             wear non-sparking or conductive shoes. Floors should be conductive as outlined             in the National Fire Protection Agency (NFPA) standard #99. Cotton clothing             should be worn, and all metal machinery and moving parts should be well grounded             electrically, to bleed off static electricity before it can build up a dangerous             charge. No matches should be allowed in the manufacturing area. Change houses or             areas where smoking is permitted will help keep the dangers of smoking under             control. Safety training and periodic scheduled safety review meetings with             employees are required by OSHA. Close supervision during work is essential to             safety.
- WO
 
ON CHEMICAL SENSITIVITY
Sensitivity of chemical mixes not only relates to how easy (or difficult) one             can "strike fire" by friction or impact, but also involve other             considerations. The level of heat energy required for combustion (ignition             temperature), and whether the chemicals are susceptible to spontaneous             combustion should also be considered. The choice of fuel and oxidizer may very             well be compatible and free of the danger of spontaneous combustion when water             dampened or wet mixed. However, in some instances, the choice of fuel and the             ratio of fuel to oxidizer, can render the same mix sensitive to heat by having a             low ignition temperature characteristic. The lower the ignition temperature, the             easier a spark, (electrical or mechanical), can set it off.
I have often heard pyros say, "Oh, that stuff is safe, its not             sensitive, don't worry!" Compared to what? Everything we measure in life is             relative compared to some standard. So how do we base our judgment on the "relative" sensitivity of fireworks chemical mixes? Unless you have             access to a good explosives engineering library, a lot of money for special             apparatus, a lot of time to set-up and conduct experiments, and a good education             to interpret the data of your findings you can't make an accurate judgment on             relative sensitivity.
Attempts at establishing practical measurement standards are being made and             that's good! (See AFN #15, Oct. '82, pp5 "Impact Sensitivity;" by L.             S. Oglesby). However, the fireworks industry generally does not have any             practical standards of sensitivity measurement other than government specs for             military signals. For the most part, the work of professionals and amateurs             alike has relied on the knowledge (or hearsay) of those who are experienced and             willing to share their knowledge. Unfortunately, there are, and always will be,             those who work in the "dark", without regard or ability to conduct             controlled experiments for determining relative sensitivity.
Be it a question of chemical compatibility or heat, friction, shock, and             impact sensitivity;; we must presume an inherent and intrinsic danger exists by             treating all chemical mixes with equal care. It can be dangerously misleading to             use the words "never" and "always". However, when handling             fireworks chemicals, we must never trust in the unknown and must always respect             what is known.
The following is a list of chemical combinations known to cause sensitivity             problems. Next to each listing are letters to indicate the types of sensitivity.             The code key is given as follows:
F = Friction
U = Unstable (poor shelf life, slow decomposition or unpredictable)
AVOID THESE COMBINATIONS OF CHEMICALS
1. Potassium Chlorate & Sulfur, Sulfides, or Sulfates - F, I, SP, U
2. Barium Chlorate & Sulfur, Sulfides, or Sulfates - F, I, SP, U
3. Potassium or Barium Chlorate & Ammonium Compounds - F, I, SP, U
4. Potassium or Barium Chlorate & Calcium Carbonate - F, I, U
5. Potassium or Barium Chlorate & Aluminum - F, I, U
6. Barium or Potassium Nitrate & Aluminum (when wet) - U, SP
7. Ammonium Perchlorate & most Nitrates - HY, U
8. Untreated (coated) Magnesium & any Oxidizer - SP, U
9. Barium Nitrate & Sodium Oxalate - HY, U
10. Barium or Potassium Chlorate & Sodium Oxalate - HY, U, F, I
Readers are invited to contribute additional chemical combinations known to             cause any sensitivity problems (and the reasons) for future publication. Mail             any comments to:
Bill Ofca
Hyde Park, NY 12538
THE PROFESSIONAL DISPLAY OPERATOR
What is a professional display operator;? (Hint: the emphasis here is on             professional;). He is a person thoroughly familiar with the most important             aspects of the responsibilities associated with the safe handling,             transportation, and use of exhibition fireworks. He knows not only the how-to             and rules, but the reasons why specific directives exist.
A true sense of pride and accomplishment can be enjoyed through the proper             handling and control of display fireworks. Likewise, when rules are ignored or             broken, the consequences can be serious. Those who operate public fireworks             displays belong to a rare and unique "brotherhood" of professionals.             Again, the emphasis is on professional. The training and experience a display             operator receives, when reflected in responsible attitude, behavior and actions             on every display, allows the title to be fitting and deserved.
The professional display operator will be respected as professional when his             conduct and attitude shows he is a respectable person. Think about it! When a             stranger approaches him on a display, is he polite and does he show any manners?             That stranger might be the customer, a politician, a display committee member,             etc. That stranger might also be a relative or close friend of any of the above.             Does the display operator avoid the use of foul language in public? People             nearby have ears and fireworks events are usually family type entertainment             affairs. Even the common spectator tells stories, often exaggerated beyond the             bounds of truth, to their friends and relatives.
Are YOU a display operator;? During a display, the eye of the public is upon             you! Ten thousand pairs of eyes are focusing in on you, off and on, as evening             approaches. Giving someone the finger, or pulling a moon is definitely juvenile.             Likewise, reckless horseplay and fighting among the display crew does not show             maturity or professionalism. Smoking near the fireworks set-up also looks bad.             You may know its safe (if it really is), but those watching will think you are a             reckless menace. Drinking beer in public before a display is definitely             forbidden. Not only does it look bad, it is bad. In many states, it is against             the law for display operators to drink alcoholic beverages before or during a             fireworks display. Local ordinances may include an open container law forbidding             drinking in public. Many display sponsors post signs forbidding spectators from             bringing beer to the displays. How outraged do you think the sponsor will be if             you are spotted drinking a beer? It is grounds for charges of criminal             negligence in the event of an accident, no matter what the cause. Do you show             respect for the display sponsor and his committee workers?
The display sponsors (customers) have the final authority when you are in             their territory. They are paying big bucks for a good display, which includes             your services. In other words, you are his paid servant and the spectators are             guests. If you respect the relationship of this arrangement, customers will             always treat you with dignity. After all, they understand you are the expert in             your field, and they need your services to present the display. Likewise, the             professional display operator is aware that repeat business depends on how the             customer perceives him. - WO
 
WHOSE JOB IS DISPLAY PLANNING?
With July 4th, 1986 now history, it appears there were more tales of public             display accidents than ever before. I wonder if that's true or only seems that             way because of the heightened awareness of this year's insurance crunch. One             thing is for sure: the accidents that did happen received intense media             coverage, especially by newspapers. Most of the stories either mentioned or             focused on the insurance situation while suggesting inevitable law suits. There             is nothing like "fanning the flames" to make the industry look bad!
Perhaps the reported public display accidents were not as many as the             negative media reporting would lead one to believe. After all, there were tens             of thousands of displays exhibited on July 4th across the nation. Yet one             accident is one too many. Year after year, the fireworks industry has taken a "beating" from the news media. Accidents at public displays are             preventable.
When a serious accident occurs, it is usually the result of several safety             rules, not just one, being ignored and broken. The errors may even be traced             back to the factory at the assembly table, with everyone along the way sharing             some of the responsibility. If the display sponsors and the shooters do their             jobs, public injuries can be avoided, even if a bad shell is experienced. All of             the rules of shooting are more or less premised on the assumption that fireworks             are somewhat unpredictable and the next shell could be a bad one. From             barricading the mortars to placement of the spectators, the set-up should             consider public safety first, with those what-if situations thoroughly thought             out. The consequences of every choice must be thought out. We are free to             choose, but we are not free to avoid the consequence of a bad choice.
Public safety is the responsibility of all parties involved, not just the             shooters on display night. Jobbers, shooters, and manufacturers must insist on             quality work from their production facilities. Cheap shells only invite             accidents in the field. The customer must be educated by the salesman seeking a             signature on the display contract. The salesman should be an experienced shooter             and knowledgeable in all display set-up situations. A customer must be taught             what his responsibilities are. Important safety concerns should be bound in the             contract. For example, safe distances from the mortars to the spectators, parked             cars, inhabited buildings, etc. Defining the responsibility for a rope line,             crowd control, fire protection, police protection, auto parking, clean-up of the             site after the display, etc., should all be detailed in the contract.
The customer must be made to understand his cooperation is essential to the             planning and success of the display because, after all, it is his display. If             there is an accident that he could have helped avoid, it will come out in the             trial. The customer will be sued along with anyone who had anything to do with             producing the display. Lawyers name everyone. If the customer doesn't know what             to do or how he can help, it won't get done.
The display salesman, the shooter's crew chief, and the customer, should all             meet at the display site a few weeks ahead to plan the display, check and             measure distances, establish where the rope line will be, and discuss what to do             about wind and wind direction, fall out ash, etc. A set of written rules and             guidelines should be given to the customer. All the customer's crew men should             get a copy of these safety rules and concerns. To take for granted the customer             knows how to plan a successful safe display is a serious breach of             responsibility. Every display site should be reviewed in person to assure             conformity within the law, and common sense safety for the size of the display             and the size of the crowd. - WO
 
SHELL SPIKING IMPROVES SAFETY
"Spiking" is the term used by shell makers for binding a cylinder             shaped aerial shell with twine. The twine is usually wrapped around the shell             from end to end vertically, and then spirals down the side to where it is tied             with a clove hitch knot. Generally, most shells have at least             eight or more equally spaced vertical spikes (or double spikes) of twine. The             number of turns spiraling down the side of the shell varies with the type and             size of the shell. Spiking is always applied before a shell is pasted-in.
Spiking is the traditional method of "Italian" shell design. It             comes from the days of making shells by first rolling a "bag" casing             around a wooden former. Discs of cardboard or "chipboard" were             inserted into the bag casing to form the casing ends, which were secured by             folded down, over-lapping paper from the ends of the rolled cylinder. After the             shells were loaded and the last discs (with fuse;) were inserted and secured,             the shells were spiked with strong twine of cotton or flax. It is obvious the             spiking adds strength to the shell and improves the burst spread, but how             significant is shell spiking to safety?
In recent years, most professional manufacturers have phased out laborious             shell rolling in lieu of using inexpensive paper cans. The paper can walls are             more ruggedly constructed than the rolled bag casing, and have impressed many             shell makers to the point of producing "stringless" shells. Those who             remember their trials of designing stringless shells will recall compromises             that had to be made to preclude extensive instances of flower potting when the             shells were fired. The lift charge had to be reduced or heavier paper had to be             pasted-in, or internal as well as external discing, had to be introduced, etc.             For light weight shells, the problem of flower potting may not have occurred.             However, with heavier shells of more complex performance, the problem is             pronounced. Some shell makers overcame this problem by introducing more and more             turns of heavy kraft paper when rolling the shell casing or when pasting-in.
During the 1983 display season, I witnessed approximately 600 four inch color             with report shells perform flawlessly. Each shell was constructed identically             using thin wall (.030") paper cans with: 1/8" thick chipboard discs on             the ends, spiked with strong twine, pasted-in with 4 turns of 60# kraft paper,             and lifted with 2-1/2 ounces of FFA black powder. The shells traveled high, had             wide symmetrical bursts, and the reports ignited, then timed out, and detonated             perfectly at a high altitude.
As an experiment near the end of the season, twenty more shells were made             identical to the first 600 with only one difference: the twine spiking was left             out. Out of the 20 fired, 8 flower potted, 1 failed to ignite the salute after             the aerial burst, and all had burst out the fuse end of the shell casing,             driving the salute at high speed in the opposite direction, sometimes             dangerously toward the ground.
I have concluded the sudden occurrence of flower potting was caused by             inertia of the shell contents and the weakened, unstrung shell ends. The shell             is resting at zero velocity at the bottom of the mortar when, at the moment of             ignition, it accelerates to 100+ feet per second muzzle velocity. The "g" forces of the shell contents act internally against the bottom of             the shell casing causing it to separate from the shell walls. The shell casing             tends to accelerate faster than its contents, and perhaps, if no lift flame were             present, would exit the mortar empty, partially empty, or severely cracked.             Without twine spiking, the shell would have to be "beefed-up" with             extra pasted-in paper and/or have its lift charge reduced. While this would help             get the shell successfully launched, it does not resolve the aerial burst and             report ignition problem, especially when paper cans are used.
The experiment left no doubt in my mind that shell spiking improves safety.             This is not to say that all stringless shells are unsafe. There are many shell             makers producing good quality stringless shells, and have overcome the problems             mentioned here in their own peculiar ways. However, most of the stringless             shells I have come across were usually lightweight, no larger than 4" diameter and no heavier than 1.5 lbs. unlifted. The more complex "stringless" shells I have seen had rather heavy wall paper cans or heavy wall rolled cans,             heavy discing inside and out on both ends of the shell, and were pasted heavy             with extra paper. They also used extra generous portions of commercial FFA black             powder for bursting or used flash bags. All this extra work and material to make             a performing "stringless" shell makes me wonder if any material cost             or labor is saved at all. - WO
THE DREADED DUD
PART 1
Anyone who has operated a public display and experienced the frightening             embarrassment of seeing the tracer sparks of a fired shell die, knows the dread             of a dud shell. Several thoughts race through one's mind: ...will it break low?             (probably not if the fuse died), ...will it come down and hit someone? ME?,             ...feet!, do your stuff!, ...shush! I wish the spectators would stop booing so I             can hear where it lands, ...Oh God, I pray no one gets hit, ...here it comes,             ...no car roofs please...THUMP! Phew! On the ground safely! ...Get another shell             up quickly, ...find it at all costs later!, ...can't let anyone get it,             especially children!
Then after the show, you find the dud or maybe have to return at daybreak to             search. All the time you are looking, new thoughts creep into your head: was it             only an isolated shell or are there more? ...is it only this type of shell or             will it happen randomly throughout the inventory? ...Why? ...What caused it?
This subject has played on the minds of shell makers, professional and             amateur alike, for as long as aerial fireworks have been made. Yet, very little             has been written on the subject. Many have isolated the problems, and now avoid             the causes with varying degrees of success, including this writer. Others are             still perplexed and curious, maybe even desperate to solve their dud problems.
In this continuing series on the subject, we will examine some of the             apparent causes of the dreaded dud and what some shell makers are doing to avoid             the problem. The purpose will be to present and share varied opinions             objectively so that readers may form their own opinions and conclusions, or             investigate this controversial subject further.
If we broadly define a dud shell as the result of a malfunction that caused             the shell to deviate from normal performance or intended design during lift             (firing), than we can identify duds in four categories:
1. The "flower pot;" effect
2. Time delay fuse ignition failure
3. Time delay fuse failure after ignition
4. Shell burst ignition failure after time delay fuse burn through
In subsequent issues of American Fireworks News (AFN), we will attempt to             look at each of these categories objectively, while presenting some of the             reported possible conditions that may create the dreaded dud. The subject is             controversial because it addresses the heart of reasoning behind the decision of             some professionals in areas of shell design such as: discing technique, shell             pasting, time delay fuse orientation to the lift charge, and whether or not to             cross match time delay fuse, etc. We will briefly state facts and present some             design techniques and allow you to form your own conclusions. We hope to             stimulate the thinking process. (To be continued ...)
- WO
THE DREADED DUD
PART 2
In part one of this continuing series, we can easily agree the dud aerial             shell is a common safety concern of all shell makers, pros and amateurs alike.             In broad definition of the dud, it was said we can place the phenomenon in four             categories: (1) the flower pot shell, (2) time delay fuse ignition failure, (3) time delay fuse failure after ignition, and (4) internal shell ignition failure             after fuse burn through.
The Flower Pot Shell
The flower pot shell gets its name from the visual effect of a giant flower             bouquet. From the launching mortar, the observer sees a vertical blast of colors             in a column in which the colors spread while ascending, to create a flower             bouquet pattern. The cause was the shell exploding in the mortar or within a few             feet of the mortar muzzle. If the shell was a salute or contained flash report             effects, a real danger of the mortar exploding is a possible consequence. (A             good practice of many experienced display operators is to shoot ordinary flash             salutes (aerial maroons;) only from cardboard mortars. There have been observed,             many factors, or perhaps combinations of factors, which are possible causes of             the flower pot shell. Some of these conditions are as follows.
1. Too much black powder lift charge can release excessive shearing forces             around the shell that tear at the shell edges, exposing the shell contents to             the lift flame. It has also been suggested, the rapid acceleration of the shell             causes compression of the shell contents (.i.set back;) against the shell             bottom, creating interior shear. Another possibility is set back compression of             shell contents, friction, or impact, causing stars to collide and ignite,             especially when potassium chlorate stars are present. This is an excellent             reason why shells should have their contents packed tight during assembly, with             no moving parts.
2. Lift charge particle size may be too small. Generally, FFA grade             commercial black powder is used to lift cylinder shaped shells. Smaller grain             powders burn quicker and can create the same problems of too much lift charge.
NOTE: Sphere shaped ball shells from the Orient are lifted with smaller grain             powder than FFA but the sphere shape makes a much stronger shell casing than a             cylinder. Ball shells can take the harder acceleration and pounding presented             with small grain black powder.
3. Paper and Paste: Not enough paper pasted around the shell, improper             pasting technique, inferior paste, or wrong paper for ".i.pasting;-in",             have all been suggested as possible causes of the flower pot shell. A shell of             weak wall strength has flower pot potential.
4. Inferior strength on the end of the shell exposed to lift. Most shell             makers are using paper cans these days. With proper design, the paper can shell             can be made with dignified performance. Some shell makers place a cardboard or             chip board disc on both ends of the shell. Some disc only the lift end. Some             place a disc inside and outside the paper cap of the can. Others disc only the             outside, while still others disc only the inside. There are variations within             each technique, such as disc thickness, double discing on the outside of the             shell or combinations of discing with paper tape sealing or glue sealing. All of             the above techniques are used extensively and successfully among shell makers.             The key factor is to achieve the required strength and flame barrier seal, to             withstand the lift forces when the shell is fired.
5. Improperly sealed time delay fuse, especially if the fuse end of the shell             is also the lift powder end (shell fired with fuse down). Some people use animal             hide glue, some use Elmer's white glue, while still others use hot melt glue.             Whatever the glue, the important factor is to seal around the fuse with a fillet             that has no gaps of even the tiniest pin hole size. A pin hole leak can allow             lift flame into the shell or be the weak spot to allow the lift blast to tear             into the shell. Remember, the lift is encased usually in a "bag" rolled around the shell (.i.nosing paper;). Even with the time delay fuse on             top, flame gasses from the lift are guided to, and encased around the time delay             fuse by the nosing paper and blow-by space between the shell wall and mortar             wall. One interesting observation is that the many shell makers who use animal             hide glue exclusively to seal time delay fuses, also fire their shells with the             time delay fuse up or opposite the lift charge end of the shell. This is because             of the brittleness of hide glue and its tendency to crack after drying,             especially during the blast of lift. Of course, Roman fuses or "spoolettes" are always fused up due to the tendency of the powder core to blow through from             the lift pressure and blast.
Proper shell design and close attention to details are necessary ingredients             to eliminating the flower pot problem. Once design details have successfully             overcome the flower pot problem, workers must develop consistent work habits (in             a manufacturing situation) to assure the quality of each shell, thereby             eliminating the random occurrence of the flower pot dud. - WO
THE DREADED DUD
PART 3
In part one of this continuing series, we can easily agree the dud aerial             shell is a common safety concern of all shell makers, pros and amateurs alike.             In broad definition of the dud, it was said we can place the phenomenon in four             categories: (1) the flower pot shell, (2) time delay fuse ignition failure, (3)             time delay fuse failure after ignition, and (4) internal shell burst ignition             failure after time delay fuse burn through.
Time Delay Fuse Ignition Failure
This is perhaps the most controversial aspect of the dud shell phenomenon. It             has been the cause of many heated debates among shell makers who profess their             theories with strong conviction and authority to justify the way they make their             shells. The question is: what's better, firing a shell with the time delay fuse             up or time delay fuse down? It appears there is no right or wrong way to fire a             shell in this regard, as it is many factors that determine the success or             failure of shell performance. However, the shell design and construction             overview may mandate one way or the other in regards to fuse orientation. For             example, I believe most shell makers agree that shells made with spoolettes             (rammed Roman fuse;) should be fired with the fuse up to avoid flower pots due             to the fuse powder core blowing through under lift pressure and blast. Since the             bulk of shells made today are made with the 1/4" diameter Japanese or             Chinese time delay fuse, this discussion will focus on its use.
Some shell makers cross match the time delay fuse on the outside of the             shell, a short distance from the starting end of the fuse. This is done by             piercing the side of the fuse and threading a short piece of black match or             thermolite through the hole. When the shell is to be fired fuse up, a piece of             quickmatch is used to transfer ignition fire from the time delay fuse cross             match at the top of the shell, down alongside the shell to the lift powder             charge at the bottom of the shell. This is called the "pass fire". The             long quick match shell leader fuse is introduced into the nosing paper at the             top of the shell, terminating at the time delay fuse cross match, and tied off             within the gathered nosing paper at the top of the shell. This is surely a             successful and reliable method when assembled properly, yet some disadvantages             have been noted:
1. There is a risk of the fuse leader pulling out of the nosing paper             connection (top of the shell) when shells are handled. For example, when             lowering a heavy shell into a mortar or when handling chained groups or bundles             such as when loading flights (salvos) or finale mortars.
2. Ignition failure can occur if the quickmatch leader only slips, nearly             pulling out of the nosing, and the shell is then loaded into a mortar with the             problem undetected. The shell leader burns and stops, failing to ignite the             cross match, extension quickmatch pass-fire and lift charge. The result is a             live shell hung up in the mortar.
3. Time delay fuse ignition failure has occurred when a defective piece of             black match was present in the cross match hole. During handling, sometimes the             black powder coating on the match cracks, crumbles and falls out of the string.             Misfires in this category are rare, but it has been known to happen upon             examination of the recovered dud.
4. Lift ignition failure has sometimes occurred when the time delay fuse             cross match fired, but the quickmatch extension (pass-fire) to the lift charge             didn't. This can be observed when a shell leader fires, with first a delay equal             to the burn time delay fuse, then the shell flower pots or detonates in the             mortar. Similarly, when the pass-fire does ignite, but for some reason delays             lift charge ignition, low breaking shells have been observed. Again, a pause             between the snap of the shell leader firing and the discharge of the shell from             the mortar was observed, which leads one to suspect the time delay fuse was             burning during the pause. Two conditions have been known to cause this. First,             if string is tied around the time delay fuse and pass fire quickmatch, the pass             fire can be choked if the string is too tight. This will definitely delay the             quickmatch until fire burns through the choke. The second is similar to the             first. If string is tied tight around the shell body to secure the pass-fire             quickmatch, a choke delay is formed beneath, where the string pinches the             quickmatch. If there are multiple chokes in the pass-fire, there will be             multiple small delays that add up.
Some shell makers cross match the time delay fuse and then fire the shell             with the time delay fuse down, in contact with the lift charge. The shell             quickmatch leader enters the nosing paper at the top of the shell and proceeds             down along the side of the shell directly to the lift charge. The side of the             shell in contact with the quickmatch paper piping is dabbed with pasted to             prevent the leader from slipping during handling. The flame of the lift charge             ignites the time delay fuse cross match. If the shell is made properly, and the             time delay fuse sealed well, the risk of flower potting can be eliminated. The             major weakness in this method of time delay fuse ignition is in the cross match.             Dud shells have been examined and found to have the time delay fuse sheared off             at the cross match hole. Apparently the piercing of the side wall of the time             delay fuse (for the cross match;) weakens the wall strength, such that the lift             blast tears off the end of the time delay fuse and cross match. This too is a             rare occurrence but does happen under the right conditions. Some of the             variables that can contribute to this happening can be: amount of lift charge,             placement of the match hole from the end of the fuse, size of the cross match             hole, thickness of the cross match, and how much force was used to insert the             cross match, etc. This problem can be eliminated with using thermolite igniter             cord as a cross matching material. The thermolite is thin and very reliable.             Because it is thin, a much smaller hole can be punched in the time delay fuse.             Caution must be exercised with using thermolite igniter cord;: it is friction,             impact and heat sensitive. Medium speed thermolite seems to be less sensitive             than fast speed thermolite. However, the same precautions need to be applied.             Avoid sources of heat coming into contact with thermolite such as hot melt glue,             etc. Avoid hitting, striking, scratching, stepping on, smashing, and rough             handling, etc., of thermolite igniter cord.
Some shell makers will split and prime the time delay fuse with a slurry of             black powder. The slurry may be in combination with nitrocellulose lacquer or a             dextrin and water mixture. Lacking any experience in this method, I have no pro             or con evidence to convey. However, it should be noted that this is the method             used extensively in the Orient to make Japanese and Chinese shells. The             incidence of dud oriental shells due to the failure of the fuse primer to take             fire is extremely rare, attesting to the success of this method.
It should be clearly understood that there may be many other convincing             factors, both pro and con, to each method of shell making detail, that are             unknown to this writer. The "best" method is the method that             successfully and reliably works for each shell maker. By all means, safety             should be the criteria for judgment. - WO
THE DREADED DUD
PART 4
In part one of this continuing series, we can easily agree the dud aerial             shell is a common safety concern of all shell makers. In broad definition of the             dud, it was said we can place the phenomenon in four categories: (1) the flower             pot shell, (2) time delay fuse ignition failure, (3) time delay fuse failure             after ignition, and (4) internal shell ignition failure after time delay fuse             burn through.
Time Delay Fuse Failure After Ignition
The shell is loaded in the mortar, fuse lit, then "thump"! It's             airborne with a healthy spark tracer from the 1/4" diameter Japanese time             delay fuse. The shell is about half way along its flight to the apex when all of             a sudden the time delay fuse tracer dies. The shell peaks and then falls with a             heavy smack into the ground.
Upon dissection and examination, more often the fuse quit burning at the             point where it passes through the discs and sealing glue. One immediately             suspects a defective fuse due to a break in the powder train. However, this is             unlikely, as the hot burning gases will tend to flash over any small gap. Users             of Japanese time delay shell fuse are generally satisfied with its reliability and quality. Its performance has established a high confidence level among shell             makers.
Another thought is the glue (perhaps white or similar types) penetrated the             asphalt layer of the time delay fuse (under the outer paper wrap) and             contaminated the powder core. Again, this too is unlikely. I have conducted my             own tests in this regard by submerging several 12" long pieces of fuse in a             gallon of Elmer's glue for 30 days, leaving only 1" of fuse on each end             unsubmerged. After 30 days the container was opened, the fuse removed and test             burned, all without failure. While it is possible an occasional "dead" spot may appear in the powder core or asphalt layer of Japanese time delay fuse,             it is highly unlikely it would consistently occur at the point where the fuse             passes through the shell end disc. I suspect I am not alone in experiencing this             type of dud situation. (Please note, I am referring specifically to the use of             Japanese time delay fuse, not Chinese. I have found Chinese fuse to be of             inferior quality to the point of unreliable and unsafe. Most of the problem with             Chinese or Taiwanese time delay fuse have been poor quality in the powder core,             mainly due to the chemicals being too granulated and poorly mixed.)
Some people who use hot melt glue to seal the Japanese time delay fuse and             experience core burn out where the fuse passes through the hot melt glue and             disc, will suspect the heat of the hot melt glue causing the asphalt layer of             the fuse to melt and penetrate the fuse core. Not so. I submerged several long             pieces of time delay fuse in our hot melt glue system hopper tank to test this             theory. The molten glue was at 375 degrees F. After 30 minutes, I removed the             fuse and it all performed flawlessly.
Here is the real cause! On properly pasted shells, the paper will be             thoroughly soaked with wheat paste which will be in intimate contact with the             time delay fuse. Until the shell has dried, the water will saturate the outside             layer of paper on the time delay fuse and travel within the paper fibers along             the entire length of the fuse, much like the wick of a kerosene lamp. When the             wetness reaches the inside cross match, (presumed black match;) the cotton             string easily absorbs water and conducts it into the time delay fuse powder             core. The powder core then migrates the water as far as the discs and perhaps             further. As time passes and the shell dries, including the outside of the time             delay fuse, a wet spot remains within the fuse core (you guessed it) at the             point where the fuse passes through the discs. This progression of events was             observed by taking apart shells at subsequent daily intervals after they were             pasted and when not allowed to dry quickly. It was observed the stars also             became wet and mushy in some shells around where they contacted the cross match.             Remember, this does not happen to every shell, but to a percentage at random             throughout the inventory. It was especially prevalent when shells were pasted on             cloudy or rainy days and could not be quickly sun dried.
The obvious answer to avoiding and eliminating this problem is to dry shells             quickly. Sun drying of shells is not a perfectly reliable method in climates             with high relative humidity or when rainy days can occur on a random,             unpredictable basis. The best method is to dry shells in a safe building or room             where hot air is ducted in and circulated, perhaps with the aid of a ceiling             fan. Shells can be thoroughly dried to a crisp within 48 hours with this method.             The air should not be recirculated or ducted back to the hot air furnace as it             will be laden with moisture and only serve to increase the humidity of the             drying room thus slowing the drying process. Fall, Winter and Spring are the             best seasons for pasting and drying because the cooler the air temperature, the             less moisture it can hold. Now, as the temperature of this air is increased, the             capacity to hold moisture increases greatly. On a hot, humid summer day, the air             would have to be heated 20 or 30 degrees F higher than the outside atmosphere to             gain any drying benefit. Thus, the Summer months are not best for shell drying.
If sun drying is the only available method, it is suggested at least 7 days             of rain free drying be allowed for the best assurance against duds in this             category. Remember, the longer a shell stays wet, the larger the dud risk. Also             be aware, too little water in the paste can reduce the strength of the dried             shell wall due to insufficient paste penetration into the paper. Skimping on the             paste is not the answer, fast shell drying is. - WO
THE DREADED DUD
PART 5
In Part 1 of this continuing series, we can easily agree that the dud aerial             shell is a common safety concern of all shell makers. In broad definition of the             dud, it was said we can place the phenomenon in four categories: (1) the flower             pot shell, (2) time delay fuse ignition failure, (3) time delay fuse failure             after ignition, and (4) internal shell ignition failure after time delay fuse             burn through.
Internal Shell Ignition Failure After Time Delay Fuse Burn-Through
When a single break color shell (cylinder shaped) is fired it will usually             spin at a high rate of RPMs as it ascends. When this type of shell is made with             a spoolette or rammed Roman time delay fuse, shell internal ignition failure has             been known to occur. Many shell makers believe the cause of failure is             centrifugal force expelling the flame, sparks and perhaps a loose layer of fuse             powder along the core train, as the shell is fiercely spinning. This is the only             known defect of this kind for spoolettes, and indeed, rare.
On one occasion I had a bad experience with flash bag shells and another time             with salutes. Both involved failure to ignite flash powder. On both shells, I             had used Japanese 1/4" diameter time delay fuse and decided an internal             cross match was not necessary. Boy, was I wrong! When observing a piece of             Japanese time delay fuse burning, one sees a hot flame burst of out the             terminating end of the fuse. This misleads one to believe a cross match on the             terminating end (inside a shell) is redundant. I especially didn't think so             since the end of the fuse was nestled into flash powder. The result was an             average of 5 out of 10 shells dudding (50%)! While the terminating spurt of             flame out the end of the fuse is certainly hot enough to ignite flash, I now             believe the duration of the flame is too short (at least 50% of the time) to             raise the contacting flash powder to ignition temperature. It appears the             temperature and duration of the flame spurt out the terminating end of the fuse             are on the threshold of flash ignition, as the results of 60 shell firings was             exactly 50% failure. In each case, the shells were disassembled and the fuses             shown to have burned through. By following the rule of always cross matching the             shell-internal end of the time delay fuse, I have not since experienced a dud of             this nature in over 25,000 shells.
In this series of articles on, "The Dreaded Dud", I have tried to             remain objective in sharing many ideas and observations. I hope it has             enlightened the thoughts of those who have been "in the dark", or             perhaps has provoked ideas in others who may now investigate the phenomenon from             a more exact and scientific study. Until then, the generalized ideas presented             here will remain conjecture based on the observed evidence. Readers must form             their own conclusions. - WO
 
CAUSES OF DISPLAY DEFECTS
PART 1
Fireworks defects occurring during a display are defined here as anything             that causes a deviation from a normal intended function. Malfunctions that have             been experienced on occasion are often the fault of an operator such as a             loading and firing mistake, equipment set-up error, or sloppy set piece or             finale assembly work. There are also unpredictable malfunctions as a result of             defective fireworks. The aim of this and future articles is to discuss the             common malfunctions, causes, prevention, or action to take in their event. Both             operator error and material defects will be discussed in the following             categories: (1) low breaking shells, (2) the "flower pot" shell, (3)             dud shells, (4) flight or salvo problems, (5) finale problems and (6) set piece             problems. When these problems occur, it is a rare exception, not the norm.
The intention of these articles is not to get into an in-depth study of             assembly or functional detail, but to isolate common errors and causes of             display problems.
Low Breaking Shells
A shell that breaks low causing colors to fall burning to the ground, or             other effects such as reports to go off on the ground, is usually caused by             insufficient lift pressure in the mortar from which the shell was fired. The             most common reason (on hand fired displays) is, the operator placed the shell in             the wrong size mortar pipe. For example, a 4" shell cannot be put in a             3" mortar but it can be placed in a 5" mortar by mistake. When this             happens, the propellant lift charge gas pressure escapes around the outside of             the shell instead of concentrating its driving energy underneath the shell. The             result is the shell "puffs" out of the mortar, goes about 50 feet into             the air, arches over and then falls toward the ground. The shell will burst low             on its way to the ground scattering burning stars towards the ground. If the             shell was a color with report or a multibreak shell, the remaining effects will             continue to go off on the ground. If this should ever happen, it is imperative             that all shell "ready" boxes or other such containers of live shells,             be kept tightly closed or covered. Anyone on the crew who first notices this             problem must quickly holler out and warn the others. The first sign of this type             of problem-error will be the sound of the mortar at discharge. A "whoosh" or "foomp" sound should be an alarm signal. The             normal discharge sound is a good cracking report - "thump!", which may             sometimes ring the steel mortar pipe. Experience will teach the new operator the             proper sound, and a low break will definitely sound different and grab             attention. Other causes of a low break shell are a cracked mortar pipe, or too             little lift charge when a shell was manufactured. These causes are very rare,             however, and even a shell with reduced lift charge, when fired from the proper             size mortar, will still achieve a fairly safe altitude when it bursts. If a             mortar is cracked, or the bottom blown open, all shells fired from that             particular mortar will be low breaks. This happens only when shells are             repeatedly fired from an aluminum or heavy gage PVC plastic mortar with a wood             bottom plug. It has never happened with a steel (welded bottom) mortar, except             when shells detonate within. If a steel pipe blows its bottom, it suddenly won't             be there anymore with only a crater left behind. Aluminum or plastic mortars             must never be used as battery mortars, (those reloaded during a hand fired             display;). Steel mortars have been know to develop cracks only if they overheat             while taking a constant pressure pounding from repeated firings. This is why two             3" and two 4" steel battery mortars should be issued on every hand             fired display. By firing alternately between the two mortars of each size,             overheating is avoided. The larger 5" and 6" mortars can absorb and             dissipate much more heat due to their shear mass and surface area. Also there             are fewer 5" and 6" shells in any display compared to the quantity of             3 and 4" shells, which comprise the bulk quantity of display shells.
Lower than normal altitude breaks can occur if a shell is not seated in the             bottom of the mortar when fired. Gas pressure and driving energy is expended in             the void beneath the shell with reduced force to send the shell to its normal             altitude. This problem has been observed when a tight-fitting shell is lowered             into a mortar and then becomes stuck half way to the bottom. It would be insane             to try to push the shell down with a hand or even a tool. If the shell is then             fired to clear the mortar, the result will be a low star burst.
In the next issue, the "flower pot" shell, along with more display             safety tips, will be discussed. - WO
 
CAUSES OF DISPLAY DEFECTS
PART II
Fireworks defects occurring during a display are defined here as anything             that causes a deviation from a normal intended function. Malfunctions that have             been experienced on occasion are often the fault of an operator, such as a             loading and firing mistake, equipment set-up error, or sloppy set-piece or             finale assembly work. The aim of this continuing series of articles is to             discuss the common malfunctions, causes, prevention or action to take in their             event. The intention of these articles is not to get into an in-depth study of             assembly or functional detail but to isolate common errors and causes of display             problems. In the last issue, low breaking shells were discussed. We now continue             with:
The Flower Pot Shell
A flower pot effect is caused by a shell bursting in the mortar at the same             instant the lift charge has fired. The reason may be due to a damaged or             defective shell that has "weak wall" construction or too
much lift powder. Sometimes a shell will burst as it is leaving the mortar or             just a few feet above the mortar. In any event, the shell is in vertical motion             at a high velocity from the lift charge, which will cause the bursting stars             and/or effects to blossom out in a vertical direction much like a mine shot or             flower bouquet. Multiple break shells, color and report shells, or multiple             report (effects) shells, will usually have their effects go while ascending             vertically. For this reason, flower pot display shells, if they occur, are not "usually" hazardous. There are two cases where a definite hazard             exists: (1) If a salute is fired from a steel mortar and it should flower pot             (steel shrapnel) and (2) if a hard breaking ball shell should burst just after             it leaves the mortar pipe.
In the first example, this is the reason salutes must never be fired from             steel mortar pipes, only cardboard! If this rule is observed, the danger is             minimized.
In the second example, the hard breaking ball shells burst with equal force             in a spherical direction. If a ball shell flower pots while in the mortar, it             will create a large mine shot in a vertical direction. If the shell bursts             within a few feet of leaving the mortar, it will drive high velocity flaming             stars (bullets) in all directions radiating from the center of the burst. This             is one important reason (of several) the "ready box" or shell             container must be covered or have its lid shut tight as the shells are launched.             In the event a large caliber oriental ball shell bursts within a few feet of the             mortar muzzle, a real danger exist for the operators. Safe distance with remote             electrical firing or the erection of a body-protecting barricade to crouch             behind (such as the Japanese are commonly known to use) are the only real             protection that can be established.
The instance of flower pot shells are rare when good quality shells are             fired. However, they do sometimes happen, even with the best shells. Regardless             of the statistics, you never really know what the next shell is going to do.             Therefore, the thoughtful, professional operator will take the necessary             precautions, as if the next shell fired will be a flowerpot of the worst kind.             And then if it should happen, the consequences may only be disappointment that             the shell didn't make it into the sky.
The next article in this series will discuss "dud" shells. - WO
 
CAUSES OF DISPLAY DEFECTS
PART III
Fireworks defects occurring during a display are defined here as anything             that causes a deviation from a normal intended function. Malfunctions that have             been experienced on occasion are often the fault of an operator, such as a             loading and firing mistake, equipment set-up error or sloppy set-piece or finale             assembly work. The aim of this continuing series of articles is to discuss the             common malfunctions, causes, prevention or action to take in their event. The             intention of these articles is not to get into an in-depth study of assembly or             functional detail but to isolate common errors and causes of display problems.             In the last issue, flower pot shells were discussed. We now continue with:
The Dud Shell
There are two basic types of dud shells. The first type is when a shell fires             and the burning time delay fuse goes out while the shell is ascending. The shell             does not burst in the sky but instead falls cold to the ground. A slight 5             degree tilt of the battery mortars away from spectators on a windless night will             assure that a dud, should one occur, will drop down range a ways, instead of on             top of the operators or spectators. If there is any wind or breeze, you must             take it into account before set-up. Wind direction and the location of             spectators are very important factors in determining the exact placement of             mortars. Should a dud fall to the ground, it MUST be found after the display at             all costs! If it falls to the ground near spectators, it must be found and             guarded immediately, with the spectators moved a safe distance away until it can             be disposed. Also keep in mind you cannot be sure there were no duds in the             grand finale. It's impossible to track every shell in a finale. Therefore, a             good search of the display site is mandatory after the display. If possible,             return at first daylight to closely inspect the display site and fallout zone.             If you cannot return at first daylight, at least have it in your contract that             your customer must do the inspection before allowing any children into the area.             If you KNOW you have a dud and have not found it on the display night, you MUST             make every effort to locate it at first daylight. Failure to do so may result in             more legal grief than you can imagine with your negligence in the center of the             plaintiff's claim.
When a cold dud is found, the proper way to dispose of the shell is to dig a             hole in a remote place and bury it, out of the way of prying eyes of children.             Some experts claim you should soak the shell in a bucket of water first.             However, if the shell is a plastic one, it should be soaked outdoors in a bucket             of solvent (such as Xylene) until the shell casing is mostly dissolved. The             remaining contents (sludge) should then be buried.
The second type of dud shell is a shell that stays in the mortar after the             quickmatch long-fuse leader has been fired. This type of dud has also been             called a "hang fire". The proper way to handle this problem is to             flood the mortar with water, then dump the soaked shell out of the mortar.             However, this is not always practical during a display and should you decide not             to, LEAVE IT ALONE! Never, repeat NEVER, under any circumstances whatsoever,             attempt to fish a dud shell out of a mortar. NOT with a stick, NOT with             ANYTHING! Just leave it alone. It is not uncommon to see the shell fire by             itself several minutes later. During hand fired displays, NEVER load another             shell on top of the dud to try to clear the mortar. This may cause both shells             to detonate resulting in the mortar bursting. Just leave the dud and its mortar             alone until after the display when you can properly flood it with water. Go to             other mortars to finish the display. This is a good reason to have at least two             mortars of each size. Remember, after flooding the mortar and retrieving the wet             shell, dig a hole and bury it in a remote location.
The next article will deal with flight (or salvo;) problems.- W.O.
 
CAUSES OF DISPLAY DEFECTS
PART IV
Fireworks defects occurring during a display are defined here as anything             that causes a deviation from a normal intended function. Malfunctions that have             been experienced on occasion are often the fault of an operator, such as a             loading and firing mistake, equipment set-up error, or sloppy set-piece or             finale assembly work. The aim of this continuing series of articles is to             discuss the common malfunctions, causes, prevention or action to take in their             event. The intention of these articles is not to get into an in-depth study of             assembly or functional detail, but to isolate common errors and causes of             display problems. In the last article on this subject, dud shells were             discussed. We now continue with:
Flight Problems
Flights of shells are salvos or multiple shells fired in a group, to             highlight the display like a miniature finale, or to display a sequence of             effects. Flights may contain as little as three shells and as many as twelve             shells. Five shells seem to be common. They may all be the same size or they may             be a mixture of sizes. Some are fired rapidly and some have pyro-fuse delays             assembled into the quickmatch between shells. Sometimes flights of the same size             are hand fired out of one or two flight racks, reloading after each launch by a             flight crew. The most common (and safer) method is to provide a rack of mortars             for each flight and preload each flight into its own mortar rack before the             display.
Hand firing flights is difficult and risky and should be avoided if at all             possible. When done, the rack(s) must be cleaned after firing and before             reloading to prevent harbored sparks from igniting the next flight as it is             loaded. Two flight racks are always better than one. Alternate cleaning and             loading allows time for one rack to cool as another is in use. Flight firing             with this method is spaced throughout a hand fired display thereby allowing time             between the flights for cleaning, cooling and reloading. Extreme caution must be             exercised in the event of a hang-fire type dud that stays in one of the mortars.             If you have only one flight rack on that display, flight firing is then over             until after the display, when the mortar can be flooded with water, and the             shell disposal accomplished. It is difficult to tell if a dud shell was left             behind after a flight is fired with this method. It is not recommended that tape             (for detecting misfired mortars;) be placed over the muzzle of the mortars after             reloading because of the risk in placing hands over the mortars. It is therefore             strongly suggested that one rack of mortars be provided for preloading each             flight before the display.
With multiple flight racks, all the flights may be preloaded before the             display, with misfire detection (masking tape) placed across the mouth of each             mortar. The individual shell leaders should be held down against the outside of             the mortar with string, rubber bands, or tape with a slight loop allowed where             the quickmatch enters the mouth of the mortar. This helps prevent misfires             caused by one shell firing and yanking on the quickmatch connection to the next             shell. When using a rack of mortars for each flight, the flights may be hand             fired or electrically fired. If hand fired, only one crew member is needed to             light each flight in turn.
When single flight racks for reloading are used, the mortars must be made of             aluminum or steel. When one rack for preloading each flight is provided, the             mortars may also be of cardboard. Reloading cardboard mortars is hazardous             because the walls tend to harbor sparks and glow or burn. Spiral cardboard             mortars tend to peel after firing causing a blockage to reloading the next             shell. When this happens, the temptation to jam the shell down with the hands or             a tool is far too great, giving credibility once again to Murphy's Law.
Single flight racks must be trenched in and barricaded on both sides with a             berm of dirt, sand or sand bags. If the ground is too hard to dig, there is a             risk the rack may jump or bounce as the shells are fired. When this happens, one             or more shells may fire at a dangerously steep angle. If a single rack is used,             the support brackets or legs must be anchored to the ground with sand bags or             stakes driven into the ground and nailed to the rack. If multiple racks are             used, the legs or brackets may be joined and nailed together for added support             to minimize bounce. One method is to align the racks such as the rungs in a             ladder and join them by nailing 2 X 4 lumber along the sides. Nails smaller than             10 d should not be used.
As with any aerial shell firing, observe the wind direction before the             display and allow a slight angle tilt on the mortars during set-up to prevent             duds or fall out from dropping on the display operators or spectators. Be             conscious of the end of the rack that will be ignited and what mortar will fire             first. Align the racks so the quickmatch fuse joining shells, burns in a             direction away from the crowd. In this way, should a shell blow in the mortar             and knock over any live mortars, they will point in a direction away from the             spectators.
The next article in this continuing series will deal with ground set-piece             problems. - WO
 
CAUSES OF DISPLAY DEFECTS
PART V
Fireworks defects occurring during a display are defined here as anything             that causes a deviation from a normal intended function. Malfunctions that have             been experienced on occasion, are often the fault of an operator, such as a             loading and firing mistake, equipment set-up error or sloppy set-piece or finale             assembly work. The aim of this continuing series of articles is to discuss the             common malfunctions, causes, preventions or action to take in their event. The             intention of these articles is not to get into an in-depth study of assembly or             functional detail but to isolate common errors and causes of display problems.             In the last article on this subject, flight problems were discussed. We now             continue with:
Ground Display Set Piece Problems
Experienced problems with set pieces have included the following: (1) Signs             hung up-side-down (2) set pieces that have fallen due to wind or vibration (3)             wheels that come off the hub spindle when a locking pin, nail, or cotter pin was             missing (4) pieces that have cross fired out of timing sequence (5) devices or             sections of a piece that have failed to fire.
Once a set piece is ignited, there is nothing that can be done to correct any             errors. If there are errors, you can only stand there in embarrassment to watch             the set piece fizzle, fail, fall, or if the wheel drops off its spindle and roll             towards the spectators, watch it part the crowd like Moses and the Red Sea.             During set-up is the time to think and inspect for possible problems. Trace the             matching to follow the sequence it will create. On signs and image lance pieces,             look for incomplete connections in the fuse, loose connections at the lance             heads, and any broken lances. Be sure the sign or image is right-side-up and the             starting lead fuse is connected before raising. Also be sure that multiple             frames of a phrase or scene are fuse;-interconnected so all parts of the piece             fire. Inspect wheels for the locking pin on the hub spindle. Unlike lance             pieces, wheels must have all match piping in perfect condition, i.e. no holes or             tears, or the piece may cross fire out of sequence. If you find any holes,             repair with masking tape. Be sure all time delay fuses are secured with string             so they won't jump fire during the initial violent ignition of the piece. Delay             fuses are usually secured with string on the back side of the wood frames.             Inspect all revolving or fountain pieces for loose gerbs or drivers. Secure             devices to frames with string and tape.
Be sure to brace all set pieces so they won't fall due to wind or vibration.             All support masts and braces should be 2" X 4" framing lumber.             Vertical up-rights should be 12' to 16' and angled braces should be at least 8'             and attached to the mast at approximately 5' above the ground. Two angled braces             should be placed 90 degrees apart. Two by four pointed stakes are driven in the             ground at the ends of the angled braces, with the braces then nailed to them.
When set-pieces are a part of a display, operators should plan to arrive at             the display site early to allow ample time for proper assembly, inspection             and/or repairs. - WO
 
A MATTER OF ATTITUDE
I am the first to admit (to myself for sure) I could have a fireworks             accident. I run that risk every day and am consciously concerned. Yet because of             that daily consciousness, the probability of an accident is considerably             reduced. My concern causes me to take steps and make decisions with regard to             safety first. It has become a matter of habit and a matter of attitude.
At the beginning of each production day, I review the operations with my             partner and co-workers. We look at set-up, equipment, routines, tools,             sequential procedures, etc. Our minds are actively scrutinizing: are we safe?             Did we overlook anything? We often check each other to assure ourselves we are             each properly concerned for each other's welfare. When one of us forgets, the             other is quick to remind. For this reason we usually work in pairs and rarely             alone. We know it's the small details that count. From shell assembly to             cleaning tools, every detail has a reason. And that ounce of extra effort to             carry out the detail is indeed cheap insurance.
Proper human attitude is perhaps the single most important factor in accident             prevention. Accepting personal humility or the act of being humble in the             absence of knowledge is most important to intellectual growth. (The more I             learn, the more I realize how much I don't know). There is nothing wrong with             one admitting he doesn't know, especially when he has reasonable doubt on a             particular subject. This often commands instant respect from others. It's             dangerous to state conjecture or opinions as fact. In the essence of a             professional atmosphere, opinions are meaningless unless you are an established             authority on the subject. Even when generating professional reports, opinions             (if necessary) are reserved for the conclusion of the report and must be stated             as the author's opinion. Saying, "I don't know," goes beyond honesty.             It opens the door to knowledge, personal intellectual growth, and maturity.
On the other hand, arrogance breeds contempt and creates an atmosphere             conductive to accidents. To argue blindly with reality, out of stubborn pride,             can lead to disaster. Some people are overly sensitive and react to reasonable             safety suggestions by easily becoming offended and defensive. Safety discussions             should be encouraged and rewarded with compliments. The topic should be "neutral territory," free of prideful defensiveness, especially if we             are stopped by a co-worker while in the forgetful act of violating a rule. Don't             get mad if this happens to you, say thanks instead. After all, the person             reminding you is looking out for your life as well as his.
Safety is a matter of attitude and I often wonder: how many fireworks             accidents to date could have been prevented by a simple, open minded, change of             attitude. - WO
 
PRO FAX
Most of you are probably wondering, "PRO FAX? What happened to SAFETY             FAX?" The truth is I wanted to expand the available subjects to write             about, including of course, safety. I spoke to AFN's editor, Jack Drewes, and we             decided it would be a good idea to write about subjects that have a professional             slant. Since I am a co-owner of a display fireworks manufacturing firm (Ed.             Note: now retired) and have been accused (more than once) of being highly opinionated (aren't we all?), I am hoping PRO FAX will be much more than             mundane. Jack and I decided that this timely feature should appeal to the many             professional operator subscribers of AFN as well as the amateur interest in             professional current events.
PRO FAX will feature safety articles as in the past but will now also include             expanded coverage of business events with the emphasis on professionalism. I am             especially looking forward to writing about subjects such as professional             display operator career development, how-to articles, the financial analysis of             a display, inside tips of how to maximize profits, and how to reduce liability             risks. I hope to stimulate controversy in some areas and maybe report some of             the reader reactions to hot topics! I would also like to impress readers with             the incredible "would you believe...." type features and I invite             readers to write to me with details of incredible experiences involving             fireworks, either pro or amateur. You can write to me at:
B & C Associates
66 Holt Road
Hyde Park, NY 12538
I promise all correspondence will be kept confidential to protect the guilty             as well as innocent! Also, if you would like to have me research and write about             any particular subject, I will be honored to read your request.
Next month, PRO FAX will feature a discussion of interest to all fireworks             display shooters.
- WO
 
WHAT ABOUT FLASH?
Of all the thousands of variations available in the elements of fireworks,             flash powder is perhaps the most spell-binding fascination to capture the             attention of most pyros. Perhaps this is due to the high energy, awesome nature             of its effects. The blinding white flash, sometimes followed by a cluster of             titanium sparks, then followed by a gut tickling sound pressure wave, is             somewhat exciting to say the least. The remarkable aspect is that flash powder             is relatively inexpensive and simple to manufacture when compared to stars, for             example. Fireworks makers (in the U.S.) use more flash and report components in             aerial shells than any other single device or color.
When accidents involving flash powder occur, the high energy, violent             performance of flash results in serious and catastrophic damage. In recent             times, the legal as well as illegal fireworks trade has experienced the (high             incidence) tragic loss of human life with almost all involving devastating flash             powder explosions. The problems that lead to "accidental" disaster are             all too common: complacency, carelessness, forgetfulness, apathy, contempt, and             blind trust ("it won't happen to me, never has, therefore never             will"). Those who fit this last category, the never-never people, cop a             narrow minded attitude of "don't confuse me with facts, my mind is made             up!" Notice that all these categories are products of the human mind:             attitude and awareness. Can it then be questioned: are the "accidents" occurring from these problems really accidents? I think not. Irresponsible             attitudes where safety is compromised can only be truthfully stated as             negligence. When a bolt of lightning strikes the powder shed, - that's an             accident;!
Lets examine some facts about flash and some safety tips on handling. A good             quality flash has a critical mass of about 50 grams (less than 2 ounces). This             means it will detonate with concussion in open air (no container), when ignited.             Less than 50 grams will burn violently but without report. Compare this with             black powder which has a critical mass of about 500 pounds!
A three inch aerial salute (2-1/2" X 2-1/2") containing about 4             ounces of flash, when ignited and if held in the hand, will dismember the human             torso, not just a hand. Large salutes are very lethal;! The thought is rather             horrifying, yet we must be realistic to understand the nature of the beast. Be             thinking about this and the safety rules before you blend your next 10 pound             (160 ounce) batch!
In a recent demonstration of the power of flash, a 1 pound bag was detonated             electrically inside a wood structured shed. The blast and fireball was awesome!             The shed was demolished with chunks scattered around where it once stood.             Imagine 100 pounds of flash in an accident;! Instantly lethal in a 25 foot open             air radius, and lethal up to several hundred feet if hit by missiles propelled             from the blast. Windows will break for a 1/4 mile radius, and buildings will             sustain structural damage to window and door frames up to 600 feet away.             Buildings within 200 feet will sustain structural damage to framing timbers.             Think about this: as the size (density) of the flash charge doubles, the force             (or energy;) of the blast increases 8 times!
Here are some do's and don'ts on handling flash;:
1. Do mix outdoors only in humid weather .i.;(above 50% relative humidity;)             to reduce the hazards of static electricity sparks.
2. Do wear only cotton clothing when mixing flash.
3. Do remove all jewelry and all metal including belt buckles.
4. Do spray yourself down and all tools, tables, etc. with Anti- Static Spray             (aerosol cans). This material is amazingly effective in eliminating the chances             of static electricity from ever occurring. I have personally tested this             material while observing the results on a sophisticated electrostatic field             strength meter. Anti-Static Spray is available in cases of 12 cans from Chiswick             Trading, Inc. 31 Union Ave., Sudbury, MA 01776-0907. Similar material can also             be purchased in super-markets and is known as Static-Guard laundry treatment             spray.
5. Do screen all chemicals separately to remove lumps. Never screen flash             powder after chemicals have been blended! The risks of friction ignition should             always be avoided. A second and very real reason for avoiding screening any             mixtures containing large quantities of conductive aluminum powder, is that the             resulting aluminum dust cloud can and does generate static charges. Although             humid conditions reduce the risk here, a life is not worth the risk.
6. Do mix flash on a large sheet of paper, rolling the pile of pre-screened             chemicals as diagonal corners of the paper are lifted and pulled towards the             center. (This is also known as the diaper method of mixing;). This method is             common throughout the explosives industry (not just fireworks) and is practiced             with making many types of sensitive explosives)
7. Do add the titanium last after most of the mixing of each batch is             complete.
8. Do mix outdoors, isolated, away from people and buildings.
9. Do limit batch sizes to no more than 10 pounds (it's now an ATF             regulation) or to the smallest batch needed to satisfy your requirements if less             than 10 lbs.
10. Do limit to one batch and one worker in the work room when charging             salute casings.
11. Do remove all charged casings from the work room to a magazine before             introducing a new batch of flash to the same work room.
12. Do wear a dust respirator when mixing flash or charging it into salute             casings.
13. Do clean up any chemical or flash powder spills immediately, especially             if titanium is present.
14. Don't store bulk quantities of multiple batches in the same container,             i.e. drums, etc. The larger the container, the heavier and harder to handle,             which can result in catastrophic consequences if dropped.
15. Don't mix in plastic bags. (static)
16. Don't store in plastic containers!
17. Don't use plastic scoops or utensils - use only wood or aluminum.
18. Don't screen flash after blending chemicals. Never screen any formula             with titanium present.
19. Don't mix, handle or use flash formulae containing potassium chlorate,             especially if sulfur, antimony sulfide or titanium are included.
20. Don't mix indoors where aluminum dust suspended in the air can be ignited             by the electric spark of appliances or light switches. The resulting blast has             been known to level buildings such as in a gas explosion.
21. Don't smoke, even in a safe area, if your clothes are contaminated with             flash powder.
22. Don't expose too many workers to flash operations. Limit the number of             workers to only those necessary to complete the assigned task (usually 1 or 2).             Keep all operations in separate sheds or limit one work room to one operation at             a time. -W.O.
 
THE STATIC SEASON IS UPON US!
With the approach of winter comes cold dry air out of the Arctic. The dryness             in the air is an essential cause of the increased occurence of static             electricity build-up on people and objects. When the air is humid, the water             vapor in the atmosphere helps to keep the static charge voltage low by "bleeding" off any "excess" electrical charge above a             certain threshold established by the level of relative humidity and the laws of             nature. As the humidity drops, the build-up of static electrical charge (and its             electrostatic field voltage;) increase. When the charged object or person comes             near or in contact with another person or object of opposite polarity charge or             ground potential, a discharge of the electricity will occur. This is when we see             a small blue spark, feel a slightly uncomfortable tingle and perhaps hear a             faint snapping sound.
Static electricity discharge is, without a doubt, the most hazardous             phenomenon in the fireworks and explosives industry. We can control the use of             non-sparking tools and keep cigarette smoking, open lights and sources of flame             out of the work place, thereby maintaining our sense of control. However, static             electricity is somewhat difficult to see coming (without sophisticated             instrumentation to warn of a build-up) and in most workshop environments it is             impossible to predict. We can, however, take some rather simple steps to             minimize or prevent the occurrence of static problems.
Anyone who mixes fireworks chemicals that contain conductive charcoal,             aluminum or other such chemicals should take precautions to guard against static             electricity hazards. The use of humidifiers in the workshop (at least 2 in a 20'             X 20' room) greatly reduces the risk. A good relative humidity gage is helpful,             and if you use one, make it a rule to not work, especially with powders, if the             relative humidity falls below 40%.
It is also a good idea to wear only 100% cotton clothing such as denim and to             watch out for visitors who may be wearing sweaters, nylon articles or other             static producing synthetic materials. Keep a few spray cans of anti-static             laundry treatment spray on hand and use it liberally.
Avoid carpets on the workshop floor. Install a conductive anti-static floor             if you can afford one. Insist that workers purchase and wear conductive shoes.             Install a conductive wall plate (connected to a good earth ground source) near             the entrance door and insist everyone touch it as they enter or after they             remove static generating overcoats. A thin chain curtain hanging in the doorway             (also attached to earth ground) can accomplish the same.
Avoid the use of plastic materials and containers that can generate static             charges. Use instead, paper or cardboard containers.
Install aluminum or copper cladding on the work bench and electrically ground             through a 100 K ohm resistor (to prevent an arcing static discharge).
All of these are good working solutions to avoiding the hazards of static             electricity and should be practiced for assuring a safer work environment. - WO
 
CHLORATES AND THE SUN
We have often heard the warnings, KEEP CHLORATES AWAY FROM THE SULFUR             COMPOUNDS!!! It's been said so often that a "ban potassium chlorate paranoia" has crept into the minds of many a pyro. I personally believe             that potassium and barium chlorate do indeed have a place in making fireworks as             long as mother nature's chemical rules are strictly followed. As Dr. Takeo             Shimizu states so well in his book, Fireworks - The Art, Science and Technique,             1981, p. 90, "It would be ideal to reject this material (potassium             chlorate;) from fireworks, but it is quite difficult even at present, because no             other oxidizer can surpass potassium chlorate in burning speed, in ease of             ignition or in noise making, using the smallest amount of composition." Potassium chlorate is also an ideal oxidizer for colored stars because it             produces a high temperature flame, rich in chlorine atoms, which intensify             colors. This allows commercial fireworks manufacturers certain economics as             well. One thing is for sure, chlorates are here to stay. Fortunately, advances             in the learning and sharing of knowledge within this industry over the past 30             years, have lead to a decline in the number of accidents involving the             chlorates. There probably aren't any professionals worth their salt today that             are not aware of the ingredients that sensitize barium and potassium chlorate.             Even so, there are those that go so far as to promote the use of a few             percentages of barium carbonate as an acid neutralizer (buffer) in meal powder,             and then dust their chlorate stars with this primer.
Accidents attributed to the use of the chlorates should not be blamed on the             chlorates but to the carelessness of the user. Perhaps the user was ignorant of             the "potential" dangers or if he knew, he forgot, or was apathetic. In             which case his future in this life and industry is limited. We've seen a lot             written on the dangers of chlorate mixtures with sulfur, sulfates, sulfides,             ammonium compounds, etc. But I haven't seen too much written about the dangers             of ultraviolet light, - the sun!
From time to time, we see articles written, or hear someone talk about the             (unconditional) merits of drying fireworks in the sun. Certain conditions do             exist where the sun can be a direct cause of a pyro disaster. Sulfur reacts with             water to create a weak form of sulfuric acid (H2SO3). Potassium or barium             chlorate reacts with sulfuric acid to form chlorine dioxide (ClO2) which is             decomposed explosively by sunlight into chlorine and oxygen. If there are any             fuels present, spontaneous combustion is a definite certainty! Think about this             the next time you are considering sun-drying chlorate stars dusted with meal or             pulverone, barium carbonate or not!
Chlorates demand to be understood. Beginners to the art should definitely             avoid fooling around with the chlorates until they understand the nature of the             beast. There are many other warnings and cautions regarding chlorates and their             incompatibility with other substances besides those mentioned here, which make             them potentially dangerous. (See also "On Chemical Sensitivity", page             5). However, in the hands of trained professionals, chlorates have for many             years produced some of the most beautiful effects offered in the fireworks art.
- WO
 
IS STAPLING QUICKMATCH HAZARDOUS?
The practice of stapling quickmatch with a staple gun has gained popularity             over the last decade. The introduction of the Hansen Tacker staple gun to the display fireworks trade rapidly grew in popularity among operators as a fast and             easy way to secure quickmatch to lance work set pieces. It appears the vast             majority of operators have never experienced any accidental ignition of             quickmatch using this method and it therefore follows reason that many would             find other uses of the staple gun to expedite work. One such use has been to             fasten quickmatch finale chain to the wooden frame of a finale mortar rack.             Common sense would dictate the user to be aware that staples are made of steel             and to avoid shooting staples near nails, other staples or hard knots in the             wood. Any ferrous metal striking a hard surface can produce sparks, which             increases the risk of quickmatch ignition. Of course, this line of thinking             presumes the black powder within quickmatch is, in itself, impervious to             ignition from the impact of a staple. Recent events indicate the contrary.
Everyone has heard of "Murphy's Law;" which states: "If             something can go wrong it eventually will." The consequences of Murphy's             Law in the fireworks industry can be extreme. If something bad can happen, it             often is too late when we find out i.e. too late for the victim of the bad             event. However, the rest of us MUST learn from the example if we are to prevent             an identical recurrence of Murphy's Law.
Perhaps many of you have learned of the tragic death of a fellow display             operator in Las Vegas last December (1984). After a lengthy and thorough             investigation, the cause of the accident was determined as the impact of a             chiseling staple against the black powder composition of quickmatch. The             operator had been loading the finale and was leaning over a mortar when the             match took fire from a staple shot from a staple gun. Samples of the match were             tested for the presence of potassium chlorate and potassium perchlorate by an             investigator, with none found. Samples of the match were also tested for impact             ignition. After many unsuccessful trials, ignition was eventually achieved. It             is theorized that the spring loaded impact of a staple gun can concentrate an             enormous amount of impact energy into the tiny surface area at the points of a             staple hence creating the conditions for impact ignition of standard black             powder within quickmatch. (Ed. Note: see following article "New Facts On             Staples", which zeros in on the most probable cause of this tragic             accident;).
Contrary to popular belief, standard commercial black powder can indeed be             set-off by severe impact. It is true that in normal and even rough handling, the             occurrence is extremely rare. However, it has been proven black powder can be             initiated from the impact of a bullet in ballistic tests. For this reason, it             makes sense the concentrated impact energy at the points of a staple could do             the same. About six years ago (1979), I had a conversation with an operator who             told me he had set off an entire finale (on a display in Connecticut) during the             afternoon of the display date. He said it happened when he shot a staple into             quickmatch to secure it to the wooden finale rack. No one was hurt in that             incident and I have not heard of a similar accident until the recent tragedy in             Las Vegas. What has astounded me is the similarity of claims from the             investigations of both of these incidents. The operator of the Connecticut             display swore to me that his staple that caused ignition did not hit any other             metal, and he had cleaned the rack of old staples before set-up. In the Las             Vegas investigation, a lone staple was found protruding from the finale rack in             front of the mortar that discharged to cause the fatality. No other metal was             found in the vicinity of that staple. I for one, am now convinced an inherent             hazard does exist in this practice. Since this controversial topic has surfaced,             I have heard from several sources, stories of a similar nature involving lance             ignition on set pieces during assembly with a tacker staple gun.
The source of ignition with lances can be: upon impact of the staple with the             quickmatch;; impact against the lance head or upon piercing the lance head and             penetration of the column of powder within the lance. Those with experience             stapling quickmatch to domestically produced lances will attest to the hard,             solid nature of the black powder primer-plug at the head of the lance. The             hardness of the prime, which extends approximately 1/4" deep into the lance             tube, appears to vary from lance to lance. I have seen the primer plug on some             lances shatter from the brittleness upon impact of a tacker staple. On other             lances within the same set-piece, the staple will penetrate without so much as             cracking the primer plug at the lance head. The color formula of the powder,             under the lance head primer, may involve oxidizers notorious for impact ignition             such as barium chlorate, potassium chlorate, or potassium perchlorate. I was             recently asked, "Does a tacker staple have enough impact energy to ignite             the color composition inside a lance after penetrating the quickmatch and primer             plug?" Perhaps, and especially if a particular lance has a shallow or soft             primer plug. We must also consider the staple is rapidly decelerating from the moment it leaves the gun and penetrates the quickmatch. In any event, the impact             compression and crushing of oxidizer crystals will, under certain conditions,             cause ignition. The hard primer plug on some lances offers the greatest             resistance to the impact of a staple. For this reason, I believe it is the most             likely place ignition will occur if it does occur.
Common sense dictates exposure must be limited if lance work is to involve             the use of a tacker staple gun. Work outdoors at a safe distance and down wind             from all other sources of explosives. Do not clutter your work area to impede             your escape in the event of accidental ignition. Move finished pieces a safe             distance away from the work zone (up wind;). Wear cotton or nonflammable and             non-meltable clothing. Keep a bucket or two of water nearby.
A trite cliche states: "History is doomed to repeat itself." This             thought manifests itself in Murphy's Law. No doubt there are staple shooting             display operators who will not see this article, or who will refuse to heed the             warnings that an inherent hazard exists when stapling match to racks or lances.             They may be blinded by self-serving motives to save an extra few ounces of work             effort. After shooting tens of thousands of staples without incident, they may             be thinking ignition can't happen. Perhaps the shooter in Las Vegas thought the             same, or perhaps it was the first time he shot a staple into match. I suspect             the "old timers" to this trade have experienced these same concerns             when they lectured their apprentices on the proper use of twine. I have seen             some of them shake their head and scowl at "new" ideas or methods.             Perhaps in their wisdom from many years of experience, they recognize the             importance of harmony with nature;'s fireworks rules. - WO
 
NEW FACTS ON STAPLERS
The Hansen Tacker staple gun has seen a resurgence of use in the fireworks             display industry this season. A supplier to the professional fireworks industry             reports the 1988 fireworks season has been the busiest ever seen for the Hansen             Tacker . Orders were backlogged for 6 to 8 weeks last Spring. This stapler is             popular for lance work quickmatch assembly, and if used, should be restricted to             only that use. Also, it should be used only outdoors with plenty of room to             escape, should there be a rare accidental ignition of the set piece while using             the tacker. (Ed. Note: See previous essay).
Many of you readers will recall a few years ago the tragic death of a fellow             display shooter in Nevada. He was assembling the grand finale of a fireworks             display, using a Hansen Tacker staple gun, when a 3" shell suddenly             discharged striking him in the forehead.
There was much talk and writing at the time about the source cause of             ignition with much speculation on many theories. The quickmatch shell leader had             apparently ignited as the display operator was firing a tacker staple into the             quickmatch, attempting to secure it to the mortar rack's wooden frame. Most             everyone agrees that black powder is nearly impossible to ignite with impact or             friction and the rare circumstances that it can happen are severe (i.e.             high-speed bullet impact;). Examination of the rack at the time revealed there             were no other staples, nails, or even knots in the wood to provide a hard             surface to cause the staple to spark. Black powder (especially dusty black             powder on quickmatch;) ignites easily from a spark or incandescent energy             source.
During a recent conversation with the general manager of a staple             manufacturing business in New Jersey, a more probable theory has come to light.             When told the story of what happened in Navada, this gentleman said, "Oh             hell, that's easy to understand! The Hansen Tacker is constructed in the same             manner as most staple guns. A spring loaded anvil is released from a cam to             strike the staple forcing it out the guides into the work piece. If you were to             fire a staple gun in the dark, you would see the sparks that sometimes follow             the staple. The sparks are created by steel against steel, the anvil against the             staple or the friction of the staples riding in the guides before it leaves the             gun. For some industries, this is one of the reasons we copper clad some of our             staple products." (This particular manufacturer does not make staples for             the Hansen Tacker;). This idea now raises suspicion that a spark was generated             in the tacker and it followed the staple into the quickmatch.
Display operators who use staple guns of any sort, beware!-WO
 
GIVING AWAY THE STORE
The serious amateur one day decides the back yard lab, and back yard             displays, are not fulfilling his "calling" to the art. Like many             before him, he may seek shooting experience with a professional company or he             may go directly into the jobbing business. "Jobbing" is a word that             describes a display contractor who is not primarily a manufacturer. (He may add             to his displays some or, at times, many of his special back-yard-lab shells for             fun or imagined advantage. A jobber sells and shoots public fireworks displays.             He is a contractor, but does not have a plant or factory, and may not even have             a storage magazine. He probably stores his shooting equipment and mortars in his             back yard, and can handle one, maybe two displays (with hired help) on the same             day. He is most likely to be a part-time pyro, who does not depend on fireworks             for his sole source of income.
This "imagined" advantage is usually born out of a lack of             confidence and experience with designing and shooting displays. The new jobber             believes he must load up the show with an excessive shell count, and perhaps             excessive shell sizes, for the allowed display budget. He thinks this will             launch him into pyro stardom, and beget a host of new customers on this new             reputation, born out of "giving away the store". Nothing can be             farther from reality.
First of all, it must be understood that no business ever succeeded by giving             away its goods and services. The practice of overloading a display with shells,             can only serve to outrage those who depend on fireworks for a living. It should             be understood that competition is stiff and pricing of product is depressed in             this industry. In other words, there is not a hell of a lot of money in this             business to begin with. Those who make money do so after working their buns off             on a continuous basis.
When displays are overloaded with shell count, the customer expects this on             every display of the same price in the future. If the jobber cuts the shell             count in the future (presumably to then make money) his reputation will suffer,             and he may not recover to remain in business. If the jobber continues to             overload future shows and, in effect, works for nothing but the fun and pride,             he will either burn out, or burn his bridges. His source of commercial shells             will get wise to his raping the market, and suddenly he can't find a supply of             shells to do his displays. Remember, it has taken years for the industry to             condition customers to price / display size ratio.
If the jobber keeps on overloading his displays, he will definitely acquire             more displays requiring him to spend more money for equipment and probably hire             shooters. Because he has been overloading displays, his profits are very low or             non-existent. Therefore he will be overwhelmed by the expenses and forced to             turn down the business. Those who go blindly ahead, borrowing money to make ends             meet, are eventually forced to fold. There are many stories floating around             about jobbers who don't pay their bills to the shell manufacturers and trade             suppliers. Perhaps their fate was the same described above. Those jobbers who             have gone this route, leave the market in a mess to be cleaned up by those             successful professionals, who depend on fireworks for a living. It's not easy to             pick-up the pieces and reconstruct a customer's trust, while trying to convince             him he should accept a legitimate proposal for a display that has 40% less             shells than last year.
So what's fair? The fireworks business is no different from any business.             Mark-up and profits are always seen as percentages by banks, accountants,             business course professors and successful businessmen. The percentages are close             to the same for all successful businesses, whether fireworks or something else.             Basically we are talking about two price structures. The wholesale and the             retail. Wholesale is the price the middleman pays the manufacturer. Retail is             the price the final customer pays the middleman. Jobbers are middlemen. When             manufacturers fire displays, they are also "acting" as the middleman.             Wholesale prices are doubled (marked up 100%) to establish retail price. Another             way to look at this is wholesale prices are 50% of retail prices. Both are             mathematically equal statements. This is true for just about all merchandising             businesses. The middleman takes his expenses out of the 100% mark-up, and what             is left are his profits. When the manufacturer acts as his own middleman when             selling displays that he will also fire, he has the advantage of making mark-up             on his products to get to the wholesale price, and then mark-up again to the             retail price. He can be more flexible with bidding or negotiating situations,             but remember, he generally has a great deal more overhead than the jobber. The             advantages are only apparent and temporary. Neither the manufacturer nor the             jobber has any competitive edge over the other. If everyone who is involved with             selling fireworks displays, both manufacturers and jobbers, would adhere to the             golden rule of selling at retail, there would be less cut-throat and more             profits for everyone. The design of the display, including insurance cost,             should add up at retail price to the customer's contract price. - WO
 
ON THE SUBJECT OF ACCIDENTS
What is an accident;? An undesired event that results in physical harm to a             person or damage to property. An accident is, by dictionary definition, "A             happening that is not expected, foreseen, or intended. An unfortunate occurrence             or mishap." Accidents are certainly unfortunate when they occur but are             they really unexpected or unforeseen?
A research firm in Hartford Connecticut recently reviewed more than 11,000             industrial accidents and found several reasons for predicting accidents in             almost all the cases reviewed. What they found was: improper maintenance, lack             of any maintenance program, no written procedures for operating equipment, no             procedure for periodic testing of controls, little or no concern for operator             training, absence of any education or training program, improper installations,             improper applications, no maintenance records, no use of log books, and little             or no common sense.
ALL accidents are caused (natural catastrophes excluded); they don't "just happen" as many people think. It can be said that accidents are             the result of two immediate concerns: (1) the existence of substandard practices             and conditions and (2) ERRORS! Whenever substandard acts or conditions are             allowed to exist, the door is open to an incident in which the result is left             largely to chance. The result can be minor, serious, major or catastrophic loss.
The basic causes of accidents fall under two categories:
1. Personal Factors
A. Lack of knowledge or skill
B. Improper motivation
C. Physical or emotional problems
2. Job Factors
A. Inadequate job standards or training
B. Inadequate design or maintenance
C. Poor working conditions
D. Equipment or tool deterioration due to aging and normal wear
E. Abusive or abnormal use of equipment and tools
Accident prevention is everyone's responsibility. Every human being has a             primary responsibility to use his only tool of survival: his mind. We have             volition to choose to think or to default into laziness and not think. When we             choose to think, we are then capable of identifying reality and exercising             control over our environment and actions. Accident prevention requires control             over the causes of accidents. We must set standards (or adopt those already             existing), identify problem areas, train and educate fellow workers, set             standards and emphasize awareness as well as conformity to those standards.             There is no trying. There is only doing or not doing when it comes to accident             prevention.
1988 can be accident free for the fireworks trade if we all take the             necessary steps to do what is necessary for accident prevention. WO
 
"UNAVOIDABLE" ACCIDENTS
Here's a story for you that reads like a novel. It's the story of an event             that really occurred in a large industrial plant.
A man removed a guard from a machine to do some oiling. The oil can he was             using had a long spout for getting into the more remote parts of the machine.             While he was oiling the machine, the guard he had removed fell over, struck the             oil can and catapulted the spout so that it cut an ugly gash across the man's             right eyebrow, just missing the eye itself. A little later this man was in the             emergency ward receiving attention for the cut. He spoke about the accident to             the nurse who was attending him. "You know", he said, "that was             an unavoidable accident;! You can talk safety as much as you please, but there             are always unavoidable accidents and this was one of them."
Then the nurse asked, "Do you mean that you are going to let that same             thing happen to you again?"
"No," answered the man, "it will never happen to me             again."
"But how will you avoid it?" continued the nurse.
"By laying the guard in another position," answered the man.
So this man, who began by proclaiming this to be an unavoidable accident,             concluded by explaining just how it might be avoided. And he, by the way, was             considered a very intelligent man by his fellow workers.
There are two things we can say on this subject of "unavoidable" accidents: (1) Accidents for which we are to blame, we tend to blame on others             or proclaim them as "unavoidable", and (2) scientific studies reveal             that 90% of the so called unavoidable accidents are really preventable.             Accidents don't "just happen." Good housekeeping, careful habits,             proper design and adequate safety training will decrease the number of so-called "unavoidable" accidents, especially in the fireworks trade where the             consequences are so severe. There is a statement which I wish we might all keep             in mind: "Accidents are someone's fault don't let one be yours!" If we             all motivate ourselves to learn and practice safety if we avoid being lazy and             take that extra step to do what's right to assure safety, it should save us and             our loved ones much suffering.
When we work with fireworks, we must constantly be on guard against             complacency. Because we work with certain chemicals and do certain operations             all the time without incident, does not assure us an accident can't or won't             happen. All it takes is a source of energy, a minute spark to create a disaster             given the right conditions. And those conditions are the ones we must avoid as             well as the source of energy;! Remember, that extra effort to promote safety or             prevent accidents is cheap insurance indeed. - WO
 
FACTORY SAFETY: OSHA & THE COURTS
No malicious intent is needed to constitute a "willful" violation             of OSHA standards, according to a ruling of the Fifth Circuit Court of Appeals.             The court further declared: "Intentional disregard of or plain indifference             to the OSHA rules makes it a willful violation. A common sense safety policy             that leaves judgment up to the workers is insufficient." The case involved             a company that warned a crew to avoid overhead power lines, but did not tell             workers exactly how far they must stay away from the lines under OSHA standards.             A worker was electrocuted when a steel pole he was maneuvering touched a power             line. The company was fined $7,150.
In another case, the claim that an employee exhibited "idiosyncratic             behavior" was ruled no defense against an OSHA citation. This case involved             a steel plate in a shipyard that fell onto and killed a worker as it was being             welded. Necessary supports were removed. The company said it was employee error             that caused the accident, but the Occupational Safety and Health Review             Commission found that a better worker training program would have prevented the "idiosyncratic behavior." An appeals court upheld the commission.
So how does this affect the fireworks industry? It is true that better than             60% of the fireworks businesses employ 10 or less people. This means that OSHA             will not target those businesses for periodic inspections. However, they are             mandated to inspect whenever they receive a complaint on that business, or if             there is ever an accident involving serious injury or a fatality.
When serious injuries and fatalities occur, one of the first questions that             OSHA officials will ask is, "Was the employee trained?" and, "What records do you have of the training;?" The philosophy involved             in the OSHA law says in effect, "If a worker is exposed to a hazard, he             must be trained so that he is aware of what the hazard is and how to avoid             it." Employers must be aware of the hazards inherent to the nature of the             work and must make sure everyone understands what those hazards are. He must             know and train his people in the correct procedure, rules and regulations to             follow, in order to avoid an accident. Further, workers must know what to do if             a dangerous situation suddenly arises and be familiar with emergency procedures             to follow in order to avoid injury to themselves and others. Where potentially             dangerous work is involved, some companies write "shop order             procedures" (SOP) which is a training document detailing the routine for             each job. The SOP lists conditions, equipment to be worn or used, hazards to             avoid and details tasks step by step. Upon training, the employee is given a             copy of the SOP and signs a document attesting he was given and has read the             SOP. The courts hold, it is the burden of the employer to provide and maintain             safety for the employees.
This thinking is basic to the law. It covers all recognized hazards. There             must be training, and hand in hand with training must be proof: procedures,             training records, records of instruction or documented evidence of some sort             that says the worker was told and shown how to do the job right. The philosophy             of training in the OSHA law doesn't stop there. They go further and say that it             is the employer's responsibility to see to it that the employee follows             instructions and protects himself from hazards. If the employee is not properly             supervised and the worker is injured because he didn't wear safety protective             equipment, for example, the law places the blame on the employer, not the             employee.
The argument that a man was told about the hazard and was told to wear his             safety equipment, but failed to follow instructions, doesn't hold water. The             attitude of the OSHA Administration (supported by the courts) is that, "Management must Manage." It is then management's responsibility to             take the steps necessary to assure that the man follows procedures and uses the             protection provided for him in the work place. One more thing to think about.             When OSHA charges and the courts find that an employer was willfully negligent             by not managing, training or removing known hazards ( for example, more than 10             lbs. of flash;) from the work shop an employer becomes wide open for civil             lawsuits regardless of the workers compensation rules. The worker's compensation             law is designed to protect employers from employee law suits in the event of             employee injury provided the injury was not willful. - WO
 
MORE ON ELECTRIC SQUIBS
It was previously mentioned (Aug '84 AFN, Safety Fax) the primer spot on             electric squibs are friction sensitive and should be regarded with care and             caution handling. Although the primer spot is somewhat desensitized by a             nitrocellulose lacquer coating, it can still be set off by rough handling such             as yanking from a quickmatch shell leader. It should also seem reasonably             logical to avoid setting heavy boxes down on top of squibs that may be laying on             a table top or to avoid stepping on squibs that may have dropped to the shop             floor. The squib itself is relatively harmless, but should be respected as a             serious source of ignition to other nearby material.
Electric squibs are in essence electric match heads. They are similar or             identical in construction to components of electric blasting caps and have             identical electrical characteristics. Squibs should, therefore, be regarded with             the same respect as electric blasting caps. They should be kept shunted at all             times (bare ends of lead wires twisted together). The shunt is an important             safety precaution. It prevents stray electrical current, either by induction or             by conduction, from setting off the squib. The shunt must not be removed until             field wiring interconnection. At that time, it is a good practice to have the             cabling shunted at the control firing box end, while connections are made at the             mortars and until just before the display begins. A specially wired shunting             connector could easily accomplish this, with the operator transferring the cable             connector to the firing panel output connector of the box a few minutes prior to             starting the display. (This presumes, of course, circuit debugging was             accomplished earlier in the day). Control panel designers should give this             safety feature serious consideration.
Electric squibs should never be stored in a magazine with other stocks of             fireworks or explosives. They should be kept separate and stored in a portable             steel box type magazine. It is possible for a nearby lightning strike to set-off             squibs via electromagnetic interference (EMI) and it has been known to happen on             rare occasions even with a good shunt in place. EMI is also a hazard in the             field and another good reason for shunting cables at the control box during             set-up and while waiting before the start of a display. Long lead wires and             cables act as antennae for absorbing EMI and radio frequency energy.             Multi-conductor cables used in field wiring should be the twisted pair type with             full shielding.
When hooking up squib wires, it is important to keep bare wire connections             from touching the ground, especially if the ground is damp. Tape over             connections or support them so no electrical contact is made with earth ground.             The reason is stray electrical currents flow within the earth's ground. Sources             of stray current can be utility pole transformer grounds (ground loop currents             between poles) or the ground plane of a nearby radio broadcasting station             transmitting antenna. Nearby high tension towers humming at 500,000 volts can             induce stray current into the ground or your antenna-like field cables. A             thunderstorm several miles away can cause stray ground current surges in your             area as lightning strikes the ground and finds paths through underground mineral             deposits, the water table or underground stream or aquifers. As little as 150             milliamps (.150 amps or 150/1000 amps passing through the resistive bridge wire             (heating element) of the squib can set it off. A standard 1-1/2 volt D cell             flashlight battery can deliver 4,000 milliamps or 4 full amps and an alkaline D             cell can deliver twice as much again. It has been recorded that lightning bolts             can deliver 100,000 full amps at a million volts in a single bolt! Given the             right conditions, a distant thunder storm that you may not even see or hear can             deliver stray ground current to your bare squib connections touching the ground.             The likelihood of the squib being in the path of a stray current is extremely             remote. However, these are the conditions that are reported to have caused             disasters with similar electric blasting caps over many years of experience by             blasting engineers.
It should be understood that voltage is the electrical "pressure" that causes electrical current or amps to flow in a circuit. Current flowing             through a resistance creates heat which dissipates energy. The more current             flowing , the more heat energy and the quicker it is generated. The most common             way to increase current flow where resistance is fixed, (squib bridge wire plus             length of circuit wire) is to raise the voltage at the electrical power source.             This is the basic principle of the squibs ignition element current flowing             through a resistive wire finer than a human hair to create heat and ignite a             primer spot which produces a flame.
With more and more electrical firing of display fireworks taking place each             year, the operators must recognize and practice a new set of safety guidelines.             Without forming new electrical safety habit awareness or by taking squib safety             for granted, accidents will occur given the right conditions. Many will agree,             including myself, that electrical display firing is far less hazardous than hand             firing. Yet we must be aware of and respect the subtle dangers lurking in the             shadows of ignorance and avoid complacency in order to seek out and enjoy safety             perfection. - WO
 
UPDATE ON ELECTRIC SQUIBS
Extensive studies on electrical bridge wires for explosives initiation have             been undertaken for may years at the Franklin Institute and at companies such as             Atlas Explosives, Dupont and Ireco, Inc. where this writer is employed as a             staff Electrical Engineer. Resistive bridge wires of varying length, diameter,             alloy and hence resistive and thermal value are used in virtually thousands of             devices of differing design. Devices such as: squibs (a catch-all broad and             vague term in the industry), igniters, explosive bolts, detonators of many             different sizes and shapes, safe & arm military devices and blasting caps             are to name but a few. Electric igniters (or squibs as we fireworks people call             them) are electrically very similar to the electric circuit in blasting caps. In             fact, the ICI squib so commonly used by professional display operators, is the             exact same igniter manufactured and used in Atlas blasting caps. (Atlas is a             division of Gulf Explosives, Inc.). The electrical studies made on bridge wire             initiated devices involve, for example, environmental studies of performance             under extreme conditions. These tests include, but are not limited to, freezing,             baking, pressurized submergence in salt water, mechanical shock and vibration to             many g's, static electricity discharges, and RF energy excitation of finished             devices. Parameter measurements include studies for changes in: bridge wire             resistance, elapsed time from electrical initiation to detonation, fusion time             (initiation to bridge wire melt-down time), initiation energy requirements             (all-fire and no-fire current limits), explosive power output of the device, and             high voltage static electricity sensitivity.
The all-fire and no-fire current limits, RF energy excitation effects and             static electricity effects on fireworks squibs at ambient environmental             conditions is easily recognized as a safety concern. The all-fire current is             defined as the level of applied current at which 100% ignition is guaranteed by             the manufacturer. Generally, this figure is 1.0 amps flowing through the bridge             wire after allowing for wire line losses. The no-fire current limit is somewhat             more complicated and vague as environmental conditions have a great effect on             the value. Conditions such as temperature, ground leakage current , RF energy             excitation, the presence of static charges, etc. adversely affect the value of             this limit. However, no-fire current limit is generally defined as the minimum             applied current at which a squib is guaranteed to not fire under lab conditions.             This value is generally given at 0.1 amps (100 milliamps). For field circuit             testing, the Institute of Makers of Explosives (IME) recommends the test current             for measuring the resistance of field wiring by the user be limited to under             0.01 amps (10 milliamps).
Beware of the output test current of your ohm meter. Some meters, such as the             Simpson Model 260 Volt-Ohmmeter (VOM) can output as high as 200 milliamps of             test current on the ohms X1 scale (range). To test the output of your meter, set             the meter up to read ohms and measure the current with a second meter set-up to             read current. Read the test leads of the first meter directly with the test             leads of the second meter. Check each of the ohms multiplier scales by switching             the range selector switch on the first meter.
For more detailed information on the application of firing display fireworks             with electrical squibs, I recommend readers absorb the past and on-going fine             articles written by Sam Bases for AFN. (Incidentally, I have examined Sam's             panels up close and they are truly a work of art!) - WO
 
THE RESPONSIBILITY OF CHOICE
We have all heard or read about safety abuse issues having their root cause             in such things as: risk management, or risk analysis, or poor attitudes, or             statistical observations of so many near misses equal an incident, and so many             near incidents equal an accident. All of these observations are interesting to             think about and yet are open ended without integration into the reality of human             behavior. They don't really explain WHY accidents happen and continue to happen             despite all we learn or know! A search for the root reason brings us to an             understanding of the nature of choice.
Choice and the responsibility that comes with making choices allows us to act             for our survival or for our destruction. Plants and the lower conscious animals             can act only for their survival. Their behavior in the quest for nutrition and             other survival needs is automatic. They cannot form concepts or think in             concepts and therefore are not aware of their own self concept. They have no             ego. Man has no automatic survival behavior. He does have a concept forming             conscious mind with an ego. He must use his mind to act for his survival by             identifying what is good for him or what is bad for him. He has choices and can             also choose to act for his own destruction. To be successful at surviving, he             must exercise thinking effort to raise his consciousness and predict the outcome             of his choices. He is free to make any choice but he is not free to escape the             consequences of the wrong choice. Their are several ways he can fail.
If he chooses to suspend his conscious thinking before he acts, he will make             mistakes. If he acts on his emotions or feelings instead of his conscious             thinking, he will make mistakes. If he chooses to be lazy and not do his "homework", i.e. read instructions, read labels, review safety rules,             etc., he will make mistakes. If he chooses to evade reality to satisfy a whim or             want, he will make mistakes. If he represses his mind to suspend his thoughts             because those thoughts may invoke fear, he will make mistakes. Notice how in all             these observations, a choice was involved. The choice to think or not think.
I have often wondered why the vast majority of humans spend their entire             lives evading the responsibility that comes with choice. A fundamental conflict             within each of us seems to be involved. Our self concept demands that we be             productive to be happy. We enjoy our achievements and knowledge at living             competently. Pride in our achievements is a virtue. However, we sometimes do             take chances when we suspend our conscious thinking efforts before we act. If we             make a serious mistake, we evade the responsibility and often fail to learn. We             are afraid of rejection, ridicule, emotional pain or punishment. Much of this             fear is a product of our childhood where we learned to evade truth for fear of             pain and punishment. The reality we experienced was a successful avoidance of             pain when we deceived the authority figures and the perceived threat. We learned             to avoid truth and equated it with surviving successfully. We were often             punished for telling the truth, which was always stated with innocence, then             fear. All of us have experienced this to one degree or another. We should have             been patiently taught to think, which is the root of responsibility. Instead, we             were taught rule following obedience, which is the root of a habit-forming             suspending of one's consciousness and looking to outside authorities to do our             thinking for us. The reality of this is no matter how many rules we memorize, we             will not be able to memorize a rule to solve every problem life presents us             with, nor remember it in the immediacy of an action demanding situation. At best             in this circumstance, we could only act on a feeling and most often it results             in a mistake.
There is no substitute for conscious thinking effort, and no one can do our             thinking for us. It is our nature that we have choices and can act for our             survival or destruction. Our only tool of survival is our mind. We have choices,             and must exercise thinking effort to be able to make the correct choices for             successful survival, and to live competently. Accidents involving human effort             and actions are the result of one's failure to think consciously and predict the             outcome of his actions. To be safe means to be conscious with focused awareness.
- WO
 
THE BEAUTIFUL 4" SPIDER WEB SHELL
One of the most spectacular, yet simple to make fireworks bombshell, is the             Spider Web. It is also one of the most inexpensive shells. Some companies call             this shell an Octopus, but the effect is the same. This shell packs a dramatic             punch when it bursts. Exploding with a bang, it instantly fills the sky with             golden tentacles spreading radially in straight lines and in all directions from             the center. The gold stripes are formed from the burning powdered charcoal trail             left behind as the stars are hurled at high speed. The pattern just hangs in the             sky for many seconds before fading. A four inch canister Spider Web shell, when             made properly, looks like a six inch chrysanthemum. Fire 5 of these in a salvo             or flight and an awesome checkerboard spider web fills the sky! Here's how I             have refined the Spider Web to perform better than any others I have ever seen:
Stars are cut 5/8" or 3/4" (large) square. The formulae:
FORMULA 1 FORMULA 2
Commercial Meal D 10.0 Lbs.
Potassium Nitrate 7.5 15.0 Lbs.
Air Float Charcoal 7.5 9.0
Sulfur 1.0 2.0
Dextrin 2.0 2.0
While the formulae are given in Lbs., smaller batches can be made by             substituting grams, ounces, etc. for the Lbs. or by multiplying or dividing all             the quantities by the same number, keeping ratio relationships the same. For             example, Formula 1 can be weighed out in ounces with each quantity multiplied by             two to make enough stars for 3 or 4 shells. Formula 1 is a very fast burning             star because it is 50% commercial Meal D black powder. It will ignite 100% from             the strongest flash bag. The stronger, the better! Formula 2 needs to be ball             milled for at least ten hours to be almost as fast, yet just as ignitable as             formula 1. Because it burns slightly slower than formula 1 (after ball             milling;), these stars achieve a larger spread in the sky. Ball milling also             serves another purpose. It reduces the amount of ash and shortens the charcoal             glow time. Without ball milling, some of the sparks may glow all the way to the             ground. With ball milling, the golden stripes are more uniform and more             beautiful, fading in unison. Formula 1 (less the Meal D;) can also be ball             milled to achieve uniformity and less ash. Add the Meal D after ball milling the             rest of the chemicals. Very slight dampening with a volume mix of 80% water with             20% denatured alcohol is helpful during ball milling. By slight I mean just             enough to settle the dust but the mass still feels dry and flows freely as a             powder.
Commercial quantities can be ball milled in an electric cement mixer that has             been modified. I did this by removing the blades and reinstalling the bolts to             prevent leakage of powder out of the bolt holes. I also removed the motor and             replaced it with a totally enclosed (sealed) motor, and thoroughly electrically             grounded the machine. Ball milling of a mixer charge of 28 Lbs. of Spider Web             mix, was done with a set of inexpensive Bocce Balls! The mouth of the mixer was             sealed with a sheet of heavy plastic cut in a circle larger than the opening of             the mixer vessel. The plastic cover was held in place with bungee cords. After             10 hours, the powder was absolutely beautiful and performed exquisitely after             the stars were made.
If one tries to burn the star composition after mixing and ball milling, one             will be disappointed. It appears to be smoldering and slow as if something were             done wrong. This is normal. After the stars are made by thoroughly dampening             with water, forming loafs in a frame, slicing, dicing, dusting and drying the stars perform quite differently! Burn time for a 3/4" star is less than 1             second. The star is very sensitive to low temperature incandescent heat             ignition, yet is very stable and insensitive to friction or impact. This makes             the star ideal for hard breaking flash bag bursts!
Once the stars are made, I use the following materials to assemble a 4" Spider Web Shell;:
*Paper Can with end caps 3-1/2" dia. X 4" long
*3 Chipboard discs, 1/8" thick X 3-1/2" dia.
*Jap 1/4" Time Fuse, 3 seconds between cross match
*Dime size Coin Wrapper for making Flash Bag
*Wooden Dowel, 5/8" X 4" for making Flash Bag
*Masking Tape
*Spool of 12 ply Cotton Twine or equal shell twine
*Enough good Flash Powder to fill a dime wrapper
*Igniter Cord for cross matching time fuse
*Elmer's White Glue and/or Hot Melt Glue & gun
*Pulverone or home made granulated black powder
*Wallpaper wheat paste