Making an Osage selfbow
Traditional Bowhunting -- Part Two...
July 01, 2010
Bowyer, Gary Davis, has been teaching me how to make an Osage selfbow. This is a bow made from a single piece of wood which has been split out of a 6 foot section of log. Historically, Osage was recognized as the premier bow wood because of its natural tendencies of being the strongest wood in both tension and compression. Osage was named after the Osage Indians who made it famous because their bows were known as the superior weapon in North America before gun powder.
As you remember from last month's column, Gary had shown me how to split the stave from the log and use a draw knife to remove the bark and white sapwood down to one strong layer of hard, yellow summer wood. Then we laid out the dimensions of my bow and cut it out with a bandsaw. We finished by steaming the bow blank and clamping it to a form to straighten the irregularities in the wood, bring the bow tips into alignment and add some reflex for better performance of the finished bow.
When I returned to Gary's shop, my bow had cooled while clamped tightly to the form. After removing all the C-clamps, I was pleased to see that the bow blank had taken on a smooth side profile with about 2 inches of backset, or reflex. Turning the bow to look at the frontal view, I expressed concern about the snaky curves in the limbs. "That adds character to your bow," Gary said. "Don't worry. As long as the bow's tips are in line with the handle, the bow will shoot just fine."
By stretching a string from limb tip to limb tip we could see that, when strung, the bowstring would lay nearly over the center of the handle section. Gray explained, "If the string lays closer to one side just use that side for the arrow pass side. That will, in effect, make your bow more center cut. Since the handle is in the exact center of the bow, either limb can be up."
Gary then instructed me to use a wood rasp to round out the handle area to my liking and bring the sides of the limbs square with the back of the bow.
Tillering is the most important part of bow making. Good tillering is the secret of making a serviceable selfbow. This is how you teach a wooden bow to bend into a smooth arc where every inch of the bow limb does its part of the work so that no part of the limb is overstressed. By carefully removing wood from the stiff areas each time the limb is flexed, the tapered limb can be formed into a perfect arc. All tillering is done from the belly side of the bow. (The side that is toward your belly when shooting the bow) The life or death of a selfbow is in the tillering.
"I use a three step tillering sequence." Gary told me. "Step one is floor tillering. By putting the limb tip on the floor and pushing the handle forward, even an overly stiff bow limb will flex some. Sight down the limb and notice any spots that aren't bending. Use the rasp to remove some belly wood in the stiff areas. Soon you'll have a limb that floor tillers into a smooth curve at a slight bend." Of course, you do both limbs.
|Step two is the tillering stick. This holds the bow at a slight bend while a straight edge is moved along the belly of the limb to locate any stiff areas. Remove wood to correct the bow's curve as you move down the notches in the stick until you reach the bow's brace height
After floor tillering you'll need to remove more belly wood to get the bow bending farther. Draw a pencil line down the side of the limb that creates a smooth taper from handle to limb tip. Use the rasp to reduce the belly down to the line. Then use a round chainsaw file to cut string grooves into the limb tips an inch back from each end. Hang an extra long bowstring from the string grooves and you are ready for the next step in tillering.
The second step in Gary's tillering sequence is done with a tillering stick. This is a small board with a groove on top to hold the bow and notches cut into one side to hold the string as the bow is partially drawn.
Place the T-stick upright in a vise so you have both hands free. Place the bow on the stick and pull the string down until the bow is slightly bent. Then hook the string into a notch on the T-stick. Now use a 5 or 6 inch long straight edge, moved along the belly of the limb, to study the bend. By focusing on the gap between the straight edge and the bow, you can identify any spot that isn't bending. Remove belly wood from any stiff spots. By slowly working the bow into more and more of a bend as you go down the notches on the T-stick, you will start teaching the wood to bend into a smooth arc. The use of the T-stick ends when you reach the brace height of the bow. Brace height is the amount of bend that the bow will have when strung by using a regular length string.
The final step in tillering is done with a tillering tree. This is a block on the wall to hold the bow at eye level and a pulley affixed on the floor or wall below it. Put the bow on the block, hang a scale on the bowstring and hook a rope to the scale which also runs through the pulley. By standing back and pulling on the rope you can draw the bow and also watch the weight on the scale.
Begin pumping the rope and studying the bend of the limbs at a short draw length. Use a cabinet scraper now, in place of the rasp, to remove wood from the belly of the bow in any stiff areas. A cabinet scraper will remove small curls of the yellow wood and smooth out any rasp marks left on the wood.
"Don't rush it. Take your time and go slowly with the tillering process." Gary reminded me. " A lot of 'kid's' bows are made by rushing the tillering and removing too much wood, which causes the bow to come out too light in draw weight."
As I worked, Gary instructed. "Exercise the bow by drawing it several times after removing wood. You are teaching it to bend and the wood needs to be worked to conform to the new conditions after any wood is removed. Just keep correcting the tiller as you go and keep pulling the bow a little farther each time. Approach full draw an inch at a time."
At this point my new bow was bending into a nice even curve on the T-tree.
As I approached my draw length of 28 inches, Gary commanded, "Watch the scales! Never pull the bow over your chosen finished draw weight. The goal is to stop an inch short of your draw length with a bow that is just at your chosen draw weight. That will finish the bow a couple of pounds overweight at your draw length."
I learned that final sanding and "shooting the bow in" would probably reduce the draw weight by a couple of pounds. More importantly, a selfbow should never be drawn past the finished draw length for fear of damaging wood which has been taught to bend a certain distance.
"Now the fun part!" Gary grinned. "Grab some arrows and start shooting!"
The first arrow sent arcing away from your own selfbow is a wonderful sight. I was pleased to find that my Osage bow, although not a perfect bow by any means, shot arrow after arrow with quiet and powerful authority.
Gary had suggested that I shoot the bow for awhile before putting any finish on it. "Keep an eye on the tiller until it is well shot in," he said. "You can always use a cabinet scraper to correct the bend or reduce the draw weight if you need to."
Shooting my new selfbow was a pleasure. I shot it every day, putting hundreds of arrows through it. The bow settled in at 62 pounds at 28 inches and the tiller of the limbs never changed at all.
A selfbow is not center-cut like modern, glass laminated longbows and recurves. Therefore, they are a little more particular about arrow choice. I had to find wood shafts which were spined correctly to fly well from my new bow. I don't have a chronograph but in shooting for distance, out in an open field, I found my selfbow to perform remarkably well. It consistently grouped arrows just a few paces short of those shot by a reputable fiberglass laminated longbow.
Although my bow tests were completely unscientific, I was pleased to find my simple Osage stick and string wasn't too "doggy."
Now to see if this dog hunts!