Primitive Archer
Main Discussion Area => Bows => Topic started by: uncleduck on June 26, 2010, 09:52:36 pm
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Hello I am new to the forum and have some questions about finishing my first bow and hopefully you guys can help. I am attempting to build an osage flat with the dimensions found in Bowyer's Bible Vol 1. Right now I am at the stage where I have the bow ready to tiller. If you are holding my "bow" as if you were shooting it, one limb naturally is curving towards you and one is naturally curving away from you. This is where I am at a stand still because I dont know if I should try to remedy this problem or continue with it as is. This is what it looks like:
(http://i392.photobucket.com/albums/pp9/dwilckens/006.jpg)
Without any prior experience I am unsure on how to tiller this correctly when the limbs start in different positions. Also when I laid the bow out the guy who helped me then suggested I lay it out as to avoid a knot. This layout helpfully avoided the knot, but also left the "bow" with a distinct sideways curve to it, and a string would not bisect the handle if laid from tip to tip:
(http://i392.photobucket.com/albums/pp9/dwilckens/010.jpg)
Any help on this or any other advice would be greatly appreciated. Also what do you use as a string for the tillering process??
Thanks a lot!
Dave
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Get yourself a heatgun Uncleduck. Heat the limb slowly and evenly and introduce some reflex into that limb. Its hard to see the other limb in the pic, but i think your lay out is fine. You can fix your string tracking with heat as well. I place the bow on a 2x4 and heat the area i want to move slowly and use clamps to push it one way or another. here is a pic of how i introduce reflex into a limb. the caul i am using also helps me straighten any crocked limbs to get the string running down the middle. looks like you doing fine!
(http://i727.photobucket.com/albums/ww279/sulphur7/osage%20bows/DSCF2597.jpg)
(http://i727.photobucket.com/albums/ww279/sulphur7/osage%20bows/DSCF2596.jpg)
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what are the advantages of doing this heat gun method as opposed to steaming?
also what kind of sting should I be using to tiller?
thanks
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duck, dry wood, dry heat! Wet wood, wet heat! Osage bends easily with dry heat and a heat gun works well to heat the wood. You can use any heat source like cook stove(gas or electric) or open fire but the heat gun is more convenient.
When straightening or bending osage I usually oil the wood first. I use olive oil but any veg or animal oil(fat) will work. This prevents the wood from scorching. If you use steam, you introduce moisture into dry wood and as it re-dries it can easily check(crack along the grain). If you decide to use steam, seal the wood with shellac to prevent the wood from taking on moisture. The shellac can take the heat and moisture from the steam. Shellac is easily removed later be lightly scraping or by wiping it off with an alcohol soaked towel.
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ok thanks for clearing that up for me
still wondering about a tillering string
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I use a piece of paracord for a "long string" tillering string. Any strong string or cord with little stretch should work. Just tie a slip knot in each end. When you get your bow tips moving 6" to 8" change to a regular bow string and brace your bow to about 3" to 4".
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If you don't want to bend the limbs with heat, you can just go with the curve of the stave.
My preference is to make the limb which bends towards you (deflex), the shorter lower limb as it normally has to bend through a tighter curve due to being shorter (because more of the handle is in that limb).
This helps to take some of the strain off the limb.
With a stave you often just have to worrk with it rather than trying to beat it into submission!
Del
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ok guys i got my hands on a heat gun and im going to try to reflex the limb so it even with the other limb...any advice on form dimensions? by the way the naturally reflexed limb is relfexed about 1" and the deflexed limb is naturally deflexed 2 1/8" making a 3 1/8" difference in their positions...im assuming ill have to relfex it a little bit farther than the other limb bc after taking off the form it will lose some of that artifical reflex?? also should i try to relex the other limb any more or leaave it where its at for now?