Alan,
You know the story as well as any of us that are in the game...
Jason,
Wow, loaded questions there.
Easy answers first. Yeah, just one seat, three thwarts, and two seat pedestals to add.
For the gunnels, if I had done my homework, I wouldn't have been so surprised. The 30 feet of carbon fiber tape alone was nearly a pound, then a total of 30 oz of resin. I verified the numbers after the fact, and it gets worse...I haven't added any covering coats of resin on the gunnels yet!
Would I spend the money for carbon fiber again? Uhmm, maybe. I like the strength and modulus, but I don't care for the non conformance and the subtle wet out visuals. The carbon cloth was OK as far as resin absorption, but the bias woven tape at 13.5 oz/sq yd is thick, thick, thick, .028". This, in turn, requires much resin, and we know the results of that set of parameters.
I don't know if you were joking before, but part of the answer is, yes, build a smaller boat. This Kite has much volume, and it doesn't come free.
But for a given hull, what to do to minimize weight and yet retain adequate strength?? (don't discount my use of the word adequate, it's important)
I would need to model and build a bunch of test laminates to decide upon my optimum lamination schedule. This might not be your optimum though. Body weight, gear weight, type of water, type of use, tolerance for damage, all effect each person's optimum lamination schedule for a particular hull. We can't separate geometry from the equation, it has too strong of an effect on the stiffness.
So without thorough modeling and test panels, I am leaning toward 1-1/2 layers of 6 oz, 1/4" and 1/8" Divinycell foam, and another 1-1/2 layers of 6 oz glass.
While the carbon fiber has great strength and modulus, this can be substituted with a thicker beam section.
Think about it this way:
Epoxy resin as an average of 78 lbs/cu ft. Enough resin to saturate multiple layers of carbon and/or kevlar ends up being quite a penalty. Why not use a 5 lbs/cu ft core, and back off on the excessive layers and required resin? As long as that core doesn't fail in shear you're OK.
Which then brings me to another semi-conclusion. Build a composite hull from the outside in, in a female pattern, using foam, glass and epoxy only.
Isn't this how we build strippers? But just swap out the 22 lbs/cu ft cedar for the 5 lbs/cu ft foam, you'll have virtually the same hull stiffness.
With all that said, I will still build with cedar, after all, I am stripperguy! I love the grain, the colors, the smells...
