How to make a bow
Part 2 of 3
The following measurements, with a caliper, are those of my favorite hunting bow, called "Old Horrible," and with which I've slain many a beast. The width just above the handle is 1-1/4 by 1-1/8 inches thick. Six inches up the limb the width is 1-1/4, thickness 11-1/16.
Twelve inches above the handle it is a trifle less than 1-1/4 wide by 1 inch thick. Eighteen inches above the handle it is 1-1/8 wide by 7/8 thick. Twenty-four inches above it is 15/16 wide by 3/4 thick. Thirty inches above it is 11/16 by 9/16 thick. At the nock it is practically 1/2 by 1/2 inches.
Having got the bow down to rough proportions, the next thing is to cut two temporary nocks on it, very near the ends. These consist in lateral cuts having a depth of an eighth of an inch and are best made with a rat tail file.
Now you can string your bow and test its curve.
Of course, you must have a string, and usually that employed in these early tests is very strong and roughly made of nearly ninety strands of Barbour's linen, No. 12. Directions for making strings will be given later on.
It is difficult to brace a new heavy bow and one will require assistance. In the absence of help he can place it in the vise, one of those revolving on a pivot, and having the string properly adjusted on the lower limb, pull on the upper end in such a way that the other presses against the wall or a stationary brace, thus bending the bow while you slip the expectant loop over the open nock. Or you can have an assistant pull on the upper nock, while you brace the bow yourself.
In ancient times, at this stage, the bow was tillered, or tested for its curve, or, as Sir Roger Ascham says, "brought round compass," which means to make it bend in a perfect arc when full drawn.
The tiller is a piece of board three feet long, two inches wide, and one inch thick, having a V-shaped notch at the lower end to fit on the handle and small notches on its side two inches apart, for a distance of twenty-eight inches. These are to hold the string.
Lay the braced bow on the floor, place the end of the tiller on the handle while you steady the tiller upright. Then put your foot on the bow next the tiller and draw the string up until it slips in the first notch, say twelve inches from the handle. If the curve of the bow is fairly symmetrical, draw the string a few inches more. If again it describes a perfect arc raise the string still farther. A perfect arc for a bow should be a trifle flat at the center. If, on the other hand, one limb or a part of it does not bend as it should, this must be reduced carefully by shaving it for a space of several inches over the spot and the bow tested again.
Proceeding very cautiously, at the same time not keeping the bow full drawn more than a second or two at a time, you ultimately get the two limbs so that they bend nearly the same and the general distribution of the curve is equal throughout.
As a matter of fact, a great deal of experience is needed here. By marking a correct form on the floor with chalk, a novice may fit his bow to this outline.
The perfect weapon is a trifle stiff at the center and the lower limb a shade stronger than the upper.
The real shooting center, the place where the arrow passes, is actually one and one-quarter inches above the geographic center, and the hand consequently is below this point. Your finished hand grip, being four inches long, will be one and a quarter inches above the center and two and three-quarters below the center. This makes the lower limb comparatively shorter, so it must be relatively stronger. Your bow, therefore, when full drawn should be symmetrical, but when simply braced, the bend of the upper limb is perceptibly greater than the stronger lower limb.
You will find the bow we have made will pull over eighty pounds, even after it is thoroughly broken to the string. It is necessary, therefore, to reduce it further. This is done with a spoke shave, a very small hand plane or a file. Ultimately I use a pocket knife as a scraper, and sandpaper and steelwool to finish it.
Your effort must be to get every part of the wood to do its work, for every inch is under utmost strain, and one part doing more than the rest must ultimately break down, sustain a compression fracture, or, as an archer would say, "chrysal or fret."
"A bow full drawn is seven-eighths broken," said old Thomas Waring, the English bowmaker, and he was right. Draw your bow three inches more than the standard cloth yard of twenty-eight inches and you break it. It is more accurate to say that a full drawn bow is nine-tenths broken.
It is also essential that the bow be stiff in the handle so that it will be rigid in shooting and not jar or kick, which one weak at this point invariably does.
A bow should be light at the tips, say the last eight inches, which is accomplished by rounding the back slightly and reducing the width at this point. This gives an active recoil, or as it is described, "whip ended." This can be overdone, especially in hunting-bows, where a little more solidity and safety are preferable to a brilliant cast.
And so you must work and test your bow, and shoot it, and draw it up before a full length mirror and observe its outline, and get your friends to draw it up and pass judgment on it. In fact, while the actual work of making a bow takes about eight hours, it requires months to get one adjusted so that it is good. A bow, like a violin, is a work of art. The best in it can only be brought out by infinite care. Like a violin, it is all curved contours, there is not a straight line in it. Many of my bows have been built over completely three or four times. Old Horrible first pulled eighty-five pounds. It was reduced, shortened, whip ended, and worked over again and again so to tune the wood that all parts acted in harmony. Every good bow is a work of love.
Your bow is now ready to shoot, but let us weigh it first. Brace it and put it horizontally in the vise with the string facing you. Take a spring scale registering at least eighty pounds and catch the hook under the string. Draw it until the yardstick registers twenty-eight inches from the string to the back of the bow. Now read the scale; that is its weight.
As a matter of convenience I have devised a stick that facilitates the weighing. I take a dowel and attach to one end by glue and binding a bent piece of iron so fashioned that the extremity serves as a hook to draw the string and the bent portion permits the attachment of the scale. The dowel is marked off in inches so that one can test different lengths of draw. With the bow in the bench vise, this measure hooked on the string and resting on the bow at the arrow plate, the scale is hooked in place, the dowel drawn down to the standard length and the registered weight read off on the scale.
If you still find that your bow is too strong for you, it must be further reduced. Begin all over again with the spoke shave and the file, trying to correct any inequalities that may have existed before and reducing it to what ultimately will be sixty-five pounds. Put on the string and weigh it again and again until you get the weight you want. If you have reduced it too much, cut it down two or four inches; it will be stronger and shoot better.
All yew bows tend to lose in strength after much use, and your new one should pull five pounds more than the required weight. If a bow is put away in a dry, warm place for several years it nearly always increases in strength. In our experience one in constant use lasts from three to five years. The longer the bow, the longer its life. Some, of course, break or come to grief after a short period, others live to honorable old age. Yew bows are in existence today that were made many thousands of years ago, but, of course, they would break if shot. Many bows over one hundred years old are still in use occasionally. I have estimated that the average life of a good bow should exceed one hundred thousand shots, after which time it begins to fret and show other signs of weakness.
Keeping in mind the idea of making your weapon as beautiful, as symmetrical and resilient as possible, free from dead or overstrained areas, work it down with utmost solicitude until it approaches your ideal. Smooth it with sandpaper; finish it with steelwool.
Now comes the process of putting on the nocks. A bow shoots well without them, but is safer with them.
From time immemorial, horn tips have been put on the ends of the limbs to hold the string. We have used rawhide, hardwood, aluminum, bone, elk horn, deer horn, buffalo horn, paper fiber or composition, and cow's horn. The last seems best of all. From your butcher secure a number of horns. With a saw cut off three or four inches of the tip. Place one in a vise and drill a conical hole in it an inch and a quarter deep and half an inch wide. This can be done by using a half-inch drill which has been ground on a carborundum stone to a conical point the proper length. In this hole set a stout piece of wood with glue. This permits you to hold the horn in the vise while you work it.
After the glue has set, take a coarse file and shape the horn nock to the classical shape, which is hard to describe but easy to illustrate. It must have diagonal grooves to hold the string. The nock for the upper limb has also a hole at its extremity to receive the buckskin thong which keeps the upper loop of the string from slipping too far down the bow when unbraced.
The nocks for hunting bows should be short and stout, not over one and a half inches long, for they get a lot of hard usage in their travels. They should also be broader and thicker than those used on target bows.
Two nocks having been roughly finished, they are loosened from their wooden handles by being soaked in boiling water, and are ready for use. Cut the ends of the bow to fit the nocks in such a way that they tip slightly backward when in place, but do not attach them yet.
At this point we back the bow with rawhide. Ordinarily a yew bow properly protected by sapwood requires no backing; but having had many bows break in our hands, we at last took the advice of Ishi and backed them. Since then no bow legitimately used has broken.
The rawhide utilized for this purpose is known to tanners as clarified calfskin. Its principal use is in the manufacture of artificial limbs, drum heads and parchment. Its thickness is not much more than that of writing paper.
Having secured two pieces about three feet in length and two inches wide, soak them in warm water for an hour.
While this is being done, slightly roughen the back of your bow with a file. Place it in the vise and size the back with thin, hot carpenter's glue. When the hide is soft, lay the pieces smooth side down on a board and wipe off the excess water. Quickly size them with hot glue, remove the excess with your finger, turn the pieces over and apply them to the bow. Overlap them at the hand grip for a distance of two or three inches. Smooth them out toward the tips by stroking and expressing all air bubbles and excess glue. Wrap the handle roughly with string to keep the strips from slipping; also bind the tips for a short distance to secure them in place. Remove the bow from the vise and bandage it carefully from tip to tip with a gauze surgical bandage. Set it aside to dry over night. When dry, remove the bandage and string binding, cut off the overlapping edges of the hide and scrape it smooth. Having got it to the required finish, size the exterior again with very thin glue, and it is ready for the final stage.
The tips of the bow having been cut to a conical point and the nocks fitted prior to the backing process the horn nocks are now set on with glue; the ordinary liquid variety will do.
Glue a thin strip of wood on the back of the bow to round out the handle. This should be about one-eighth of an inch thick, one inch wide and three inches long and rounded at the edges.
Bind the center of your bow with heavy fish line to make the handgrip, carefully overlapping the start and finish. A little liquid glue or shellac can be placed on the wood to fix the serving. Some prefer leather or pigskin for a handgrip, but a cord binding keeps the hand from sweating and has an honest feel.
The handle occupies a space of four inches with one and a quarter inches above the center and two and three-quarters below it. Finish off the edges of the cord binding with a band of thin leather half an inch wide. This should be soaked in water, beveled at the edge, sized with glue, put around the bow, and overlapped at the back. I also glue a small piece of leather on the left-hand side of the bow above the handle to prevent the arrow chafing the wood at this spot. This is called the arrow plate and usually is made of mother-of-pearl or bone; leather is better. These finishing pieces are wrapped temporarily with string until they dry.
The bow is then given a final treatment with scraper and steelwool and is ready for the varnish.