Upper limb twist on Ipe bow? PICS*

[vanillabear?]

[PEARL DRUMS]

The poor strength of the backing may have been the reason my limb was twisted, yet perfectly even. My wife felt bad, but I told her I learned alot on this one and the next one will be that much better!

[John Cooper]

I had three failures of TBIII hickory backed ipe's before I just went to bamboo and resorcinol.  I know how frustrating that can be.  I don't know if it was the hickory backing's fault or the TBIII since I changed both variables at the same time!  Just keep plugging away.  You'll get a lot of education even off of the failures.  If I were you, I'd experiment more with that ipe since osage is harder come by up here in Michigan!      Just make sure you clean it up well with acetone.  Pictures of the "autopsy" might help us see what happened.  Did it look like the wood gave way, or the glue line?

~John

[Pat B]

I have never had a glue failure with any TB glues. I've used it with hickory and boo backings and osage, ipe, yew, mulberry, locust and other belly woods. TB glue requires two smooth, well mated surfaces. No toothing or grooving.

[PEARL DRUMS]

The backing made a clean break from the core, same place on each limb. I toothed both surfaces prior to glue up. I didnt clean the surfaces with acetone either. I knew Ipe was "oily" wood and should have known better. Thats a no-no with TBIII from what Im told. How did my tiller look in the pic by the way? I can still learn from that even if it broke. The past hickory bow's I made spoiled me, that stuff is too easy to make a bow from! I will try to get some post mortum pics tonite after work.

[Pat B]

You not only worry about oily wood but also oil from your fingers. Once a glue surface is cleaned get the glue on it anf the pieces together without pouching those glue surfaces.
  The bow seem to be stiff just off both fades then most of the bend at mid limb on both limbs...and they are not bending together. Get the area near the fades bending and recheck tiller.