Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: Dooley on October 02, 2009, 05:15:00 PM
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As I explained in a previous post,I botched my rawhide baking project on my osage stave bow and neede to remove it.
It took an entire day, but I succeded in removing the rawhide with the aid of a putty knife and a heat gun set on low, without scortching the wood. That operation went pretty well, but now one limb is warped in cross section. Two days have gone by and it hasn't flattened out at all.
What happened?
The illustration is just slightly exagerated.
(http://i674.photobucket.com/albums/vv108/grampaflyfish/warp.jpg)
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Looks like the acs cross section.
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Heat treating will do that to a limb, so maybe you got it with the heat gun a little more than the other limb, anyway as long as the limb didn't twist, it won't hurt anything unless its been overdried. If I was you, I'd just wait a few days to make sure moisture equalizes, then go ahead and retiller it. You could round the belly edges off first if you want the limbs to match.
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I haven't see that, is the stave still a tad green?
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The person I got the stave from said that it was cut in 2007. I dunno, with the thin growth rings and everything else I've run into with this bow I'm beginning to have low expectations for the outcome. Nevertheless, I'm going to redo the backing and finish the tillering. :rolleyes:
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I don't know the ramifications of this but...
If you were to take a wet rag and place it on the belly the wood would most likely take a little moisture on and expand. THis would make the concave belly flatten out. At least it works on wood left on the lawn! Not sure about osage.
Just my .02
good luck
pete
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Pete, I've been tossing that idea around in my head. Having applied heat to the back to loosen the backing, though, It just seems strange that it warped away from the heat. What aslso seems strange is that the stave had a natural deflex to start with, and that has increased since I removed the backing. :banghead:
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Did you pull any additional deflex into the bow before you put the original backing on?
It looks like the belly wood was stretched, the backing applied, then some tillered completed.
That will cause this profile when the backing is taken off.
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Actually, no I didn't. It has only been floor tillered prior to gluing on the backing. don't really mind the amount of delex,(about 1.5 inches total at the center of the handle) I'm just curious about how it came about. Tomorrow I'm glueing on another backing. Hope it goes better than the first. :rolleyes:
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it's very obvious. As Marc St. Louis describes in TBB4, and as I've experienced quite a few times, heattreatment creates a convex belly.
your results show that you haven't only tried to remove the rawhide, but you've actually tempered your bow.
the weird thing is that I would think that you've tempered the back of your bow, something you don't want to do. But According to your drawing I'd say you've tempered the belly...
Nick
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I wouldn't worry about it. You are going to round off the belly edges anyway so you will be removing the convex cross section.
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The belly on the drawing is concave. If heat treating creates a convex shape you have not heat treated the bow.
pete