: I missed the previous discussion(s) about this. That's one heavy duty layup.
: Why so bullet proof? At first glance it seems excessive but like I said, I
: missed the first part.

I began the discussion in this thread, and Bill gave me some really good feedback-

http://www.kayakforum.com/cgi-bin/Building/index.cgi/page/2

Basically, I am building a one off whitewater kayak; more of a technical steep creeker than anything. Looking for something that can handle Class IV and decent class V stuff. I created my design basically grabbing from my favorite aspects of dominant designs in the market. The link at the bottom has some screen shots of the design.

I am definitely going for bomb proof. Orignally I was looking at laminating S-Glass with Polyester through an S-P-S-P layup on the outside of my 4mm Okoume Stitch and Glue Build, with a layer of Kevlar on the inside. Bill pointed out that the great strengths of the Kevlar might be wasted on the inside next to the wood, as opposed to somewhere else in the lamination.

I did a lot of thinking, trying to determine whether a "wood core" was truely a good idea for a whitewater boat, and taking Bill's advice, as well as some from an old whitewater glass boat builder i know, and I am basically elimating the wood from being the "core material" and now its mainly just a shape holder for the outer materials. Most people build whitewater boats from molds, but i think Stitch-and-Glue will lend itself well to this boat build, even tho i will have extra, seemingly unnecessary weight.

So now the hull lamination is S-Glass : Kevlar : S-Glass: Kevlar to get work off of the strengths of both materials. S-Glass is extremely strong both in compression and tension, while Kevlar is incedibly strong in tension (not great in compression). I am going with S-K-S-K over just S-S-K-K to slightly pay tribute to ballistic armour designs, as well as squirt boat layups. I'm hoping over time that layup will be able to handle the maximum amount of abuse i can get out of those layups. I WILL be hitting rocks, so its a matter of making sure i don't bust through the hull while in the middle of a steep 9 mile class V run.

There are few boats i have heard of which will be built up quite as tough as this... so hopefully that pays off. A lot of whitewater racing boats are only 2-3 layers thick, so... we'll see.

~Johnathan