Trad Gang

Main Boards => PowWow => Topic started by: TroyH on April 04, 2008, 09:39:00 PM

Title: Will a fiberglass backing help?
Post by: TroyH on April 04, 2008, 09:39:00 PM
I've been trying my hand at making a wood laminate bow, but with not much success.  My hickory backing strip keeps cracking at a runout.  If I put a clear fiberglass backing over that, do you think I will cure the problem?
Title: Re: Will a fiberglass backing help?
Post by: TroyH on April 04, 2008, 11:21:00 PM
ttt
Title: Re: Will a fiberglass backing help?
Post by: **DONOTDELETE** on April 05, 2008, 12:11:00 AM
I would say...YES, that is what a backing is for, to help keep the bow together. You can add it to your stave/board, I do believe you use 50grit paper on the glass & a hacksaw blade on the wood when gluing-up. If your stave is tapered you can add reflex/deflex to the bow as well.
Title: Re: Will a fiberglass backing help?
Post by: wingnut on April 05, 2008, 09:19:00 AM
IT will save the bow but so would rawhide.  Glass on the back and not belly will cause the bow to take a lot of follow.  The belly will not be near strong enough.  I use this to test new belly woods.  Build a glass backed prototype and run the belly through the ringer.

But if you are having hickory problems, try bamboo or back the hickory with rawhide.

Mike
Title: Re: Will a fiberglass backing help?
Post by: TroyH on April 05, 2008, 11:50:00 AM
Let me clarify my problem.
This is a tri-lam bow.  It has a hickory backing strip, but the backing strip has cracked at a runout.  So would it be better to use glass or rawhide on such a problem?
And where is a good place get some rawhide?
Title: Re: Will a fiberglass backing help?
Post by: Pat B on April 05, 2008, 11:58:00 AM
3 Rivers and Pine Hollow both sell rawhide for bow backing. You may be able to repair the backing that is already on your bow. If you post pics we could make a better suggestions.
  What glue did you use to glue-up your tri-lam? With the Tite-Bond glues you can heat it up and the glue will release. I had to remove a hickory backing from a bow that I had used TBIII on. I called tech support for TB and they told me that at 150deg(F) the glue would release.
  Pat
Title: Re: Will a fiberglass backing help?
Post by: TroyH on April 05, 2008, 06:20:00 PM
I used Urac, so I don't think there will be any getting it loose.
Besides, the bow didn't come out as high of poundage as I had hoped, so another backing will help to increase the poundage a little.
Title: Re: Will a fiberglass backing help?
Post by: Springbuck on April 05, 2008, 08:04:00 PM
Urac will release if heated, but it isn't as cooperative as epoxy.  I get success about half the time, the rest I over-dry, scorch, or whatever.

 Glass on only the back will move the neutral plane forward (putting more of the limbs thickness under compression, hence putting the belly under MUCH greater compression) and that might be too much for hickory.\\

 I'd look for either a way to improve your hickory backing (better selection or sawing or whatever), or try a natural material like the others have said.  Rawhide, cotton or linen fabric, , etc would do great.  Fabric backings are so easy....and can look great!