How violin bow is made - material, manufacture, making, history, how to make, parts, dimensions, History
Process
Roughing the stick
1 Roughing the stick refers to the process of carving and planing the         stick to its approximate finished dimensions. The squared off blank of         Pemnambuco wood is either held
Major parts of a violin bow.
across the corner of a bench, or along the length of a special board,         and planed by hand with specially designed planes, fashioning the stick         into its characteristic octagon shape. Using a direct heat device such         as a spirit lamp or gas burner, the stick is heated slowly until it         becomes flexible enough to bend. When ready, the stick is bent into an         approximate or rough curve. When cooled, the stick is set aside, and the         work on the frog begins.
Roughing out the frog
2 The frog begins with the fashioning of the metal fittings. Several         parts require soldering as well as bending and shaping. The ferrule,         much like a half round ring, is a semicircular length of sheet silver         soldered to a flat one. The button for the adjuster needs one or two         silver rings. The other metal parts include a silver liner, which is         shaped to three facets of an octagon on a steel die, to conform to the         three facets on which it will contact the stick. If the frog is designed         with a back plate, the plate is shaped and bent to the 90 degree angle         of the back of the frog where it is to be inlaid.
The ebony wedge is trimmed to length and planed true to its center on           all sides with a small razor sharp block plane. The various metal           fittings are fit onto the frog in their respective places. Although           modern commercial manufacture uses milling machinery to accomplish           this part, the best modern builders have no problem doing this work by           hand.
The fitting of the metal to the frog begins with drilling a 3-mm hole           called the "throat" just under the area where the           ferrule is located. The ferrule is fit onto the wider part of the           throat with a knife and small chisels until it fits back flush and           level. The sides are shaped concave with a gouge. The slot             for the pearl slide, with its 20 degree under-cut sides, is next to           be shaved out with the chisels. The cavity for the hair, called the           hair mortise, is drilled and carved into the frog with a bow drill and           chisel. The liner is then fit to the narrow edge of the frog's           length using the chisels. The liner conformns to the top three facets           of the stick's octagonal shape and is the bearing surface of           the frog against the stick. A tapered silver back-plate extending from           the back of the pearl slide slot to the center facet of the liner is           inlaid to the flat end of the frog. The frog is then shaped using a           knife, files, and small scrapers made of thin steel sheet. The           decorations, called the eyes, are inlaid into the sides of the frog at           this point. Then the ebony dowel for the adjuster button is fashioned           separately on a lathe.
Fitting the frog to the stick
3 After the frog is done, the next job is to fit it to the roughed out         stick. This is done by chalking the liner of the frog and rubbing it         against the facets of the stick at the point where the frog makes         contact. Through a process of marking the stick in this way and         carefully planing, scraping, and filing the marks away, the frog is         brought into the proper contact with the three bottom facets. Then holes         are drilled in the stick for the screw and eye assembly which attaches         the frog to the brass nut at the end of the stick.
Finishing the stick and frog
4 The first step here is to fit an ivory plate to the head or tip of the         bow. A plate of ivory is prepared with a raised section for the right         angle of the "beak" with a thin lamination of ebony veneer         all along its inside surface. The ivory is glued to the bottom face of         the head.
The shaping of the head is done with a knife and files. This work           usually follows an established model and is accomplished with the           means of a pattern or template, which is alternately traced and           compared with the carving as it progresses. The elegant head models of           the classic bows are often very beautiful, and have inspired           connoisseurs the world over to collect them. All the great bowmakers           imprinted their work with their own personal style, and experts are           easily able to recognize most of the important styles, each head being           akin to the signature of the maker. Once the head is finished, the           mortise for the hair is cut into it, and the finishing of the stick           can continue.
The stick must be now brought into final dimension, a process called           graduation. The stick tapers from 3.5-5.0 mm just behind the head to           6.5-8.5 mm at the button end. Using a gauge or caliper, the craftsman           skillfully planes this transition of thickness into the stick. The           whole process must be done while preserving the integrity of a perfect           octagon. The octagon's transition into the head is most           difficult, and ends with the top three facets converging upwards, the           two side facets becoming the side of the head, and the bottom three           becoming the back of the head and the chamfers (a thin finish cut, at a 45 degree angle to the sides). All of this           work is accomplished with either the plane in the case of the facets,           or the knife and file for the detailing of the head. The stick is           simply held by hand across a flat board or the corner of the workbench           while planing the facets. The head is simply held in the hand while           finishing.
If the stick is to be finished round, as many are, the edges of the           octagon are planed away after graduation, and the stick is rounded off           in this manner to an area about 1.6-2.4 inches (4-6 cm) in front of           the frog. The area where one holds the bow is almost always octagonal.
Treating the stick
5 The bow usually has no real varnish as such because Pernambuco is         inherently dark and oily. But the stick may be subjected to a number of         chemical treatments to achieve its characteristic chocolate brown color.         Bathing the stick with nitric acid, and then following with a         neutralizing exposure to ammonia fumes is the most common color         treatment. The bow is given additional sheen and protection by a         technique known as "French polishing." This involves the         application of a dilute solution of shellac, sometimes mixed with other         gums or resins, with a lightly oiled rag held wrapped around the         fingers.
The roughing and finishing of bow sticks do not vary in technique from           hand making to commercial manufacture. Most violin bows are made           completely by hand. Only the speed of production, quality of           materials, and diligence in finishing distinguish the difference           between the mediocre and the sublime.
Lapping and hairing the bow
6 The lapping or winding acts as a grip for the stick and is often         called the "grip." It usually covers a 3-inch (7.6 cm)         length starting from just in front of the frog and going toward the tip.         It consists of some material, usually silver wire, wound in a compact         spiral fashion around the stick. Part of the winding nearest the frog is         covered with leather to protect the spot where the player's thumb         rests.
The hairing of the bow is quite routine, as the hair wears from           playing and must be frequently replaced. The horsehair is purchased           already selected, drawn, and bundled in uniform lengths. A small           amount is separated from this and a small rosined knot is fashioned at           one end using very strong thin thread. The knot is made stronger by           inserting the end of the hair into the heat of a flame, and expanding           the hair behind it. A small wooden plug is carved to fit the mortise           in the head, and the hair is turned under and fastened into the head           with this plug, which holds the hair spread across the top edge in a           neat uniform flat strip. With the frog all the way forward, the hair           is measured to length, cut off, and after much combing and arranging,           tied in a similar way at the end near the frog. Another wooden plug is           fashioned for the mortise of the frog. The ferrule is slid over the           hair and after much more combing, the hair is turned over and fastened           again with a wooden plug, this time into the frog. The hair is combed           again before pushing in the pearl slide, and again after sliding on           the ferrule. A wooden wedge is carved to fit the width of the ferrule           so as to hold the hair spread in a ribbon-like fashion. After some           more combing, the wedge is pushed into the ferrule against the hair           and trimmed off with a knife. With the application of some rosin on           the hair, for grip, the new bow is ready to play.
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