On Sep 29, 8:09*am, sisu1a wrote:
Hmmm... Judging by weight and weave, I've always thought 7725 was a
direct replacement for 92125. I can't help with 92145, but the grainy
photo in the ASW 12/15/17 repair manual makes it look a lot like 7781.

Thanks, Bob K.

Not quite. Check this direct comparison chart of 92125 vs 7725. It
also shows 92145 vs 7715, which I think is 92145's closest US
brethren. They are both close, but definitely not direct
replacements...http://tinyurl.com/4gm27mFWIW, here's a more broad Interglas
equivalency chart:http://www.canardzone.com/forum/atta...ntid=1398&d=12...

Yup, I was wrong about 92145 vs 7781, the closer match is definitely
between 92145 and 7715, sometimes known as "Rutan uni" (except, of
course, in Rutan-free zones).

However, as far as I can tell, 7725 is near enough equivalent to
92125 as makes no difference, and 7715 is close enough to 92145 as
anybody this side of Boeing needs to get. There is no seeeeeekrit
ingredient to the Interglas stuff that makes it stronger or stiffer
per unit mass than the Hexcel style equivalents.

Of course, I am perfectly prepared to be demonstrated wrong in this.
Feel free to send me 4" square, 5-ply test coupons of 92125 and 92145.
I'll match them with 7725 and 7715 equivalents, pull them apart on the
Break-o-tron, and post the results on YouTube. I'm not set up to
collect anything but the most rudimentary modulus measurements, but I
can easily do ultimates.

Thanks, and best regards to all

Bob K.