laminates grain direction?

[DonLee]

is there a preferred grain for laminates when making a glass bow? im thinking of a ASL bow, but recurve really as well.  quarter sawn vs plain sawn ? has anyone keept a record of not only thicknes but grain direction? Im thinking yes.

[Crooked Stic]

Edge grain for core will be best such as vertical laminated bamboo.as far as veneers go being so thin crazy grain gonna look better.

[Kirkll]

On an ASL design you would be better with vertical grain rather than flat sawn material for the highest strength in tension.


But..... I just spent a couple hours on the phone with Alan Case the other day talking about heavy bows and compression issues ive been having. He told me that he did some compression testing using flat grain maple and pushed it till it blew, then put it under a microscope to see the difference from vertical grain maple.

Believe it or not, the flat grain held up to extreme compression much better than vertical grain.  He said he has a test going right now using thin book matched flat grain lams that are stacked 180 degrees so the opposing grains are equalized. He expects much higher compression ratings with the two thin lams and an epoxy joint than a thicker maple lam.     Food for thought on that subject...   Kirk

[Crooked Stic]

You may be right about maple. If that's what you use for core. That the guy who concentrates on flight bows.