I have no experience building kayaks, but I've got to mention this...

My neighbor built a homemade airplane. While working on it he took fiberglass cloth (the kind that looks like burlap) and coated it with high temp silicone gasket sealer (the same kind you use on auto gaskets) using a "Bondo" spreader. I think he may have developed an entirely new material when he did this.

The result is a super tough, flexible, heat resistant, waterproof material. I've worked with many different media while building different projects over the years and I can tell you that this stuff is pretty darn cool.

You should be able to coat one side with silicone sealer, lay the piece in or over a mold, and coat the other side with epoxy or polyurethane resin to make a hard part (as opposed to flexible). Of course, you should be able to use kevlar or graphite too.

It's cheap and easy to make a fiberglass sample yourself to test and play with. You might find it has an application that fits your project... If nothing else it'd make the world's toughest Dry Bag <img src="/forums/images/graemlins/smile.gif" alt="" />

That a cool project you're working on and a beautiful boat design you've chosen. While this may not be much inspiration, here's the last boat I built (sort of). I wanted to build a sailboat with off the shelf items for a total of no more than $100.00. I pondered this a lot before coming up with the "Hobocraft" below:

Bill