Primitive Archer
Main Discussion Area => Bows => Topic started by: medicinewheel on August 30, 2007, 07:34:12 am
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i'm back with another tiller question: this is a recurve of tri-lam hickory-black walnut-jatoba and it came out WAY to strong. in the second picture the bow pulls straight 50 pounds! in the third after violating it since two days it's still not brace-hight and still around 50 and not that i could tell the bow lost any reflex! the bow is 70" long (68" NTN) ...meant to pike it if it was to weak :)
i mostly worked the sides so far and i have a trapezoidal cross-section with narrower back. the bow feels really nice and springy and the recurves are aligned perfectly.
stand up you recurve enthusiasts and give advice whats best to do next!
thanks for all the comments!
frank
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I've never worked with Jatoba but it seems to me that it has fairly high compression strength. I would go with a flattened D section for the belly especially with a Hickory back. Why did you trap the back?
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hi mark! - a friend had problems with a jatoba belly fretting; i knew i had to narrow the bow and i thought trapezoidal was the way to start. worked down some more and by now it's perpendicular almost.
but just a minute ago i realized the glueline popped between core and backing right at the handle. it's open right in the handle towards the lower limb; it's a glue failure, see no cracks in the wood...
H E L P pe-leazze !!!!
frank
ps: bow-making is so much fun---never get boared!
pps:
has anyone ever tried to inject epoxy through a needle?? is that possible if the epoxy is warmed up maybe???
the whole thing doesn't look too bad if i get glue in there and later wrap the spot...
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If you glued it up with epoxy then you could use a good quality cyano. It's thin enough that it should flow into the crack. Use good clamp pressure
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You are right Frank it is always something else,But I am a glutton for punishment as
I guess we all are. ;)
Pappy
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I've done epoxy through a needle, and it is rather challenging. Heating it up might help, but make sure you have an epoxy with a very long set time, because the heat will make it set faster. Also keep a bottle of acetone nearby, because that'll keep the needle clean. Also helps to run a bit of acetone through it before you do the glue.
The handle that popped on me did end up popping again, despite the glue. So, I wrapped it heavily at the fades with some thread (which did give it a nice look also), and that sort of fixed it. It still opens at full draw (but do keep in mind that this was a 35# bow, so not sure how it would work for higher weights), but I don't think there's any chance of the split spreading.