I thought I was getting it-but no

[Don Armstrong]

I have made 4 - D shaped bows and they all came out good or at least they are shootable and seem to be tillered OK. I decided to try a couple of reflex bows. I did a bamboo flooring board with hickory backing and a hickory with hickory backing. The bamboo flooring was about a 1/2" so I put a piece of hickory under the backing to keep the stress out of the handle but after tillering it to almost brace, the handle popped and seperated. I got it off and the glue joint was good. It pulled the bamboo fibers apart under the handle. I reglued and reduced the sides of the limbs and the belly out from the fades but the first pull on the tiller board-crack and the handle broke again. I have one more piece of bamboo flooring but is it worth putting all that work into it? The hickory bow also blew a limb after tillering to almost brace. It was bending well but I think I had a dry glue spot and it was a marginal piece of hickory. It had a narly place in the limb. Either I made some bad mistakes or maybe I have no idea what I'm doing. Any help would be greatly appricated. Two bows destroyed in a half hour did not help my confidence. Thanks, Don

[Pat B]

Don. I've build a few bows with boo flooring with marginal results. I have however seen some pretty good ones.
   I don't understand why your bows are breaking, especially the hickory backed hickory. Will you show pics of the break.      Pat

[Glenn Newell]

Don, everybody has broken bows, I had problems with handles popping off when I first stated making all wood bows. It happened twice on one bow so I glued the handle back but in 1/8th strips laminations and it is still on after 14 years, I do that to all of my all my bows now and don't have any handle problems.
I have used bamboo flooring as well and like Pat I find it marginal as well...Glenn...

[Don Armstrong]

Pat, I'll try to get a picture of the hickory bow as soon as possible. Don

[talkingcabbage]

Don,

Usually when the handle pops off, it's because the bow is trying to bend through the handle, like your D-bows.  Try leaving more wood in the middle of the bow, and only letting the limbs start bending after the handle.  Although, I'll admit, I haven't tried the boo flooring, so maybe there's another reason?

Joe

[Don Armstrong]

Joe, I only had a maxium of 1/2" to work with and it was a gamble trying to keep a few pounds and trying to get it to not bend in the fades.

Pat, here are a couple of pictures of the hickory blow up.

 

 

[adam]

I just finished building a few R/D bows that were backed with bamboo. Never used hickory so i can't help much on that. But i have a few questions. What type of glue are you using??Are you using heat to cure the glue? How long are you letting it sit under clamping pressure??

The only reason i ask is b/c i've only had one laminated bow fail. That was using Urac 185 letting it sit with clamps for 48 hours without heat. As soon as i removed the clamps the bow had basically fallen apart after 24 hours. Everything de-laminated. Since then every bow i glue up with Urac 185 goes in the hotbox for 4 hours and i give it a couple hours to cool back to room temp. and have had no problems since.

Hope this helps some.

Adam

[Pat B]

It's hard for me to tell but it looks like it failed in tension. In my experience, for hickory to fail like that it either was infected with fungi after the tree was harvested or the grain was violated badly at the break area. Pat

[Springbuck]

So you had used a power lam, but the handle popped off anyway, is that what I am getting?  Hmmm...

  I have made a bunch out of boofloo and never had that problem.  They were usually tri-lams in a R/D, and the bow didn't bend MUCH right off the handle/fades, but did bend there....

 Did the fibers pull apart crosswise, or do you mean that it tore some up, like lifted them out, so they separated lengthwise?

  On the boofloo, the handle came off, but the backing and power-lam did not fail, right?  If so, try gluing another thin (1/16" to 1/8") power lam of something pretty stiff under the handle, lke another piece of hickory, osage, ipe, etc..

  I don't flex lam bows until I am pretty happy with the shape of the fade-outs at the handle.  If you were tillering with a squared handle block on, that may be it...

[sulphur]

the power lam works great but it has to go between the backing and belly.  I found i need to start with one at least 2-3 inches longer  than the riser and 3/8" thick.  also be sure to make the ends super thin to get good glue joints.  using a power lam allows you to use wood too thin for a rigid handle.  it may take a little practice but once you get it your boo floo bows will come out perfect.

[Don Armstrong]

I did use a power lam between the handle and backing but I didn't run it far enough past the handle. The glue held but the bamboo ripped apart under the handle. I have another piece of bamboo but no backing so I'll have to wait till I can get a backing to try again. Don

[Springbuck]

Can you cannibalize the backing from this one?...

  I don't usually make power lams as thick as Sulphur, but he is dead on about the length.  Just like fades that end too abruptly off the flares, if the power lam doesn't extend past the handle you still get too much flex.

  Sulphur,  I probably never make them more than 1/4" thick, but I taper them longer and thinner, I bet.  I usually have them 2" or more past each side of the handle, and still work to get a good gradual fade off the handle piece.

[Don Armstrong]

I am thinking of doing a take down with the limbs. I cut them at the fades and they are almost perfectly matched to each other. If I can figure out the angle to mount them to a riser, I'll try to make a take down with about a 14" handle and see what happens. Don