Hickory boo rebuild suggestions

[Kidder]

I posted a few days ago about a tension failure I had on a bamboo backed hickory hill style bow. It was nicely tillered out to 45# at 29 inches when it failed. TTT was 68 inches. I was unable to glue down the fibers satisfactorily so opted to strip off the boo and reback it. My concern is that I’m going to have to sand the face of the hickory and will likely lose some more weight that way and I’d like to ensure that the weight stays up and here are my thoughts on options:
1) pike it to 64 inches and tiller it to my draw (26) opposed to the 29 it originally was.
2) use a slightly thicker boo backing than was originally on it (0.11 +/-0.01 inches I believe)
3) add a somewhat extended power lam
4) add a core lam and make it essentially a trilam - for core lam options I’ve got Osage, hickory, hard maple, walnut, and ERC.
What does the collective wisdom suggest? Thanks in advance.

[PatM]

Heve you done a tri-lam before?

[Eric Krewson]

I have done the same a bunch of times, here is what I do;

I grind off most of the bamboo but not all of it, the cracks won't go to the glue line. I leave just enough bamboo to have something to glue the new backing to. With the new backing glued on you are going be over poundage and have plenty wiggle room to retiller to your target poundage.

Here are some pictures of just such a repair;

The failed bamboo;

[Eric Krewson]

Grinding off the bad bamboo and the finished new glue surface, there is a side picture that shows the amount of bamboo I left, the picture is deceiving and makes the backing look very thick, it isn't, my rasping back to round the corners makes it look that way.

I found another picture that shows the actual thickness of the new backing and my sanding off some of the rind.

[Eric Krewson]

From here on out it is the same as making a new bamboo backed bow, I threw in a picture of the repaired bow as well, Chad Weaver (LBR on most sites) owns it and has been shooting the repaired version for over 10 years.

[Kidder]

Heve you done a tri-lam before?

I have never done a tri lam before.
Eric, this is a great idea and explanation! I should have asked the question before I removed the back I guess. Since I used TBIII I was able to essentially steam it off with a little effort and muscle. So I’m starting with the back down to the hickory already.

[scp]

The talk of core lam belongs to the laminated bows, and IMHO not quite "primitive". On the other hand, backing a bow and doing partial overlay or underlay are quite acceptable. The difference is between using hand tools and using a thickness planer. But of course, one can glue a backing and thin it down using only hand tools.

[silent sniper]

Eric, thanks for the explanation for how to apply a new backing. I have tried removing the failed backings with heat but your method of grinding it off appears more efficient and safer for the belly wood. Thanks for sharing!
-Taylor

[Eric Krewson]

When recovering a failed bow you do what you have to do, many here would say " I put failures in the burn pile", some I do, some I don't, when I want a challenge.

A little on the bow I show above;

I quit selling bows about 10 years ago, I realized there were several guys out the that worked tirelessly for free at tournaments helping out and never got the recognition they deserved.

Chad Weaver was just such a guy, he was on the go from daylight until dark at the tournaments at Enid Ms. Now Chad is BIG guy and would make two of us normal folk, he also has a crushed ankle that never properly healed that caused him a lot of grief. In spite of this, he endured the pain and never slowed down.

I call these bows "thank you bows" and Chad deserved one.  He has at least a 31" draw, the first bow had a bamboo failure shortly after I gave it to him. He loved the bow and the way the handle fit him so I didn't want to make a new bow, just restore the one I gave him initially.

He got the same bow back as I gave him initially, just a little better one this time.

[bownarra]

If you glue-up with clamps, alternate them one way then the other. All that weight on one side can cause twist.
Good luck fixing your bow.

[Eric Krewson]

The ones in the picture above are alternated. You also need to have the same sized clamps positioned at the same place on both limbs, the weight of the clamps will cause more or less reflex in a limb depending on where they are placed.