" wrote:
Amen. But, having been tangentially involved in a completely
disastrous attempt to bond Kevlar (tm) fabric to PVC foam with epoxy I
strongly advise getting advise from the fabric provider before
bonding. A Method that worked very well with both epoxy and polyester
with stitched glass didn't fly with Kevlar (literally as the structure
was a wing for an ultra-lite).

I wonder why. Incompatible binder in the cloth?
One issue with both carbon fiber & aramids (you're right, Kevlar is a
trademarked brand name) is that the cloth is much lighter than
conventional fiberglass... duh, that's a big reason to use it... but
it also means that the cloth tends to float up out of the resin. The
best way to bond it is to vacuum bag it, or use pre-preg, but it can
be laid up like conventional FG once you know to not pour on more
resin when it looks dry. Or you can use thickening/bonding agents
mixed into the resin, that holds it in place better anyway. I used
peel ply, with no vacuum bagging, over a carbon fiber & Kevlar lay-up
with very good results.

.... And, yeah, you're right, the stuff
goes all fuzzy if you look at it funny and it kills scissors. Carbon
is less of a pain to work with but you can't use it to armor existing
hulls.


It would help add compression srength as an outside layer. I dunno if
it would help with impact resistance. The yield curve for carbon fiber
(also called graphite) is almost straight, the stuff tends to fracture
and people think of it as brittle. Of course, it takes about 10x more
force than steel can withstand, but we're so used to seeing stuff bend
before it breaks that it's counterintuitive that material which
*doesn't bend* and suddenly snaps is really strong. And it also
doesn't lend itself to "soft failure" modes.

DSK