Primitive Archer
Main Discussion Area => Bows => Topic started by: DC on February 20, 2020, 01:27:41 pm
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I'm wondering if I'm taking an extra step that isn't needed. I've started using a two piece Boo backing so I can have the nodes equally spaced on the limbs. I'm putting in a short handle lam to help tie it together. (The thin white piece right under the boo) I didn't use this with a one piece backing because the backing tied it together. The two piece backing overlaps by about an inch/inch and a half. It takes a full day waiting for the epoxy to cure just for the handle lam. Do you think I could leave out the handle lam? I know the 3 finger splice is overkill but I got the jig working well so it doesn't take any more time than a "Z" splice. It keeps the splice completely in the handle too.
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Just my opinion but with all that glue surface you have with that joint I dought it would fail with out the handle lam but Im curious why you couldnt glue up the handle lam and backing all at the same time vs 2 different glue ups ?
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I don't think that extra lam is doing anything extra to protect the backing that gluing right to the handle wouldn't do. If you're worried about the integrity of the splice, you're probably good without it anyways.
But if you didn't put the handle lam in, would it look as cool? ;)
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I'm just not talented enough to put all those pieces together at once and get a good joint.
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I don't think that extra lam is doing anything extra to protect the backing that gluing right to the handle wouldn't do. If you're worried about the integrity of the splice, you're probably good without it anyways.
But if you didn't put the handle lam in, would it look as cool? ;)
It hardly shows and a leather wrap would hide it completely :D
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I might be able to get a little more overlap on the backing.
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Your splice on the boo is pretty good. I don't think you need to worry
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I think it's a waste of time. I don't think it's doing much. What's it supposed to do? Tie it together? Whats that mean? Keep it from bending? Blowing apart? All your splices look fine. I'd leave a little more depth in the center of the handle on the palm side, to help fill the natural shape of the cupped palm, and it will also help ensure it doesn't bend there on the next one, and I think you're good.
I've made a bunch of bamboo backed bows and never cut a piece of bamboo in half to better orient the nodes in the limbs. I just shift them to balance their position as best I can, and that's the end of it. Usually they're very close. So I'd say that's unnecessary as well... jmho.
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Thanks guys, pretty unanimous :D The reason for cutting the backing is the last logs of boo I bought have close nodes. On an 8 foot log the longest node is 10" and the short ones are 4". If I went one piece I would have almost twice as many nodes on one limb. It just didn't look good. Other than the many nodes it seems like good boo so I'll go with it.
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I think its a problem creation exercise..... If you keep the boo backing as a continuous piece it will never blow (terms and conditons apply ;) )
The belly, being in compression barely needs any fancy joint at all. I've done plenty boo backed with just a very short V or Z splice .
The long fancy splice is only necessary when it goes through the whole bow.
IMO the nodes aren't a problem they are just a cosmetic issue.
Even with the swell at the grip there is still some flex there and your lap joint in the boo could fail, which would make the whole thing blow.
Del
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I think its a problem creation exercise..... If you keep the boo backing as a continuous piece it will never blow (terms and conditons apply ;) )
The belly, being in compression barely needs any fancy joint at all. I've done plenty boo backed with just a very short V or Z splice .
The long fancy splice is only necessary when it goes through the whole bow.
IMO the nodes aren't a problem they are just a cosmetic issue.
Even with the swell at the grip there is still some flex there and your lap joint in the boo could fail, which would make the whole thing blow.
Del
Well, almost unanimous ;D ;D This is a cosmetic issue. I would much prefer a one piece back. Most of my boo backed bows have been two piece with no problems but then I don't shoot them a much as I should.
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DC,, I dont remember much, but I do remeber you posting something like,,simpler is better,,
that being said,, I dont think the amount of nodes being different on each limb is a problem,, sometimes things that are different make the composition more interesting,, I think you are good,,
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When in doubt, wrap with sinew. ;)
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You rounded the belly side of your splice. If that were left a little flatter you could cap that and then run Boo all way down back in one shot.
That splice is plenty tough. Tuffer than the wood I would reckon. I like the boo backing splice but prolly not needed for strength at all.
Gary D made thousands of these splices with no caps or backings on them. He always told me he thought they were stronger than one contiguous stave bow. I have never had one give up the ghost.
HH~
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As Marc says.
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More nodes means more little stiff spots along the limb. Better to keep things even limb to limb. Another reason to splice boo backings is if you have one that isn't straight. Sometimes they can be cut and then spliced straight. I tend to use most of my lower quality boo like this.
The closer you get to gluing up a pre 'tillered' lam bow the more these things matter as well.
I prefer a z-splice for boo backings as you violate the fibers less.
As for your powerlam it is unnecessary in this style of bow (belly wood is plenty thick).
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I agree that it looks better with evenly spaced nodes on both limbs although I have never had any issues with uneven spaced nodes and stiff spots in bamboo. (I do make my bamboo backings as thin as possible though)
Also I don't think you need the powerlam at all, however you can speed that part up by glueing the powerlam with ca glue, that way you can continue in an hour or so.
And for the fun of it, I even glued a v-splice with ca glue when I did not have any epoxy left. On a 56 pound bow without any problems ;D