I am going to have to learn how to do that with the pics. That's a nice way to illustrate your ideas!

I have taken scraps from stripping (both glassed and unglassed) and have done destructive testing by flexing the pieces in different directions with my hands. I believe George is right when he says the wood has virtually no strength perpendicular to the fibers, it splits easily before the panels are glassed. And I have seen graphs which show the tensional strengths of various weaves when the forces are off axis to the fibers. Again George is right. This indicates to me that it is fairly critical to have fibers running perpendicular to the length of the strips. This agrees with what Nick wrote also with the fibers taking the place of the ribs in the Adirondack guide boats.

However, as Dale points out, concentrated loads will be stressing the fibers off axis if all the fibers are 0/90. For protection against this it would be good to have some fibers in the -30/30 directions.

The structure of the kayak is similar to a box beam. I have repaired a kevlar white water kayak which had hit rocks head-on. Most of the damage was on the deck where the compressional forces buckled the deck. I repaired it by forming a hat channel down the inside center of the deck with foam and unidirectional glass. Wow did that make a difference with very little added weight! While I hope I'm not going to be running into to many things head-on, any climbing on the deck needs similar reinforcements.

What I figure from all this is that (obviously) different areas of the kayak need to be reinforced in different ways and I still need to give it more thought. I'm up past my bed time and it's getting harder to do that so I'll leave it for another time.

Thanks,
Doug