: Hi- I thought I posted this message yesterday, but apparently it didn't make
: it to the forum. Sorry for that, and if it somehow did and I'm repeating
: myself.

: I'm far enough into my current project to start thinking about non-wood
: materials. Like everyone, I want to maximize strength-to-weight and I'd
: like to use some carbon cloth in places for the weight savings, and that
: leads me to my first question. Carbon cloth is rated just like glass,
: isn't it? So if I use 5.7oz. carbon it will still weigh 5.7oz/sq yard?
: That means I'll only see a negligible weight reduction over 6 oz glass,
: but what is the increase in strength?

: Second issue is- on a day boat is the 25-30% strength increase in S-glass
: sufficient so that those of you who use this stuff on a regular basis
: (This is my first non-SOF kayak) would think it's o.k. to go with 4-oz
: S-glass instead of 6-oz E-glass?

: Assuming that what I've read that glass is stronger in tension than
: compression, I'm thinking of using a full layer of 4-oz S-glass on the
: exterior with a second layer in the hull's "damage" areas, with
: a layer of 4-oz. S-glass on the interior, and the cockpit area reinforced
: with carbon fiber cloth.

: I'm sure that I'm not being innovative and someone's had the same idea, so if
: you can let me know how it worked I'd appreciate it. I'm only going to
: build this boat once, so I'd rather spend a few extra bucks to do it
: right.

: thanks-

: m

Carbon fiber is cool to play with and does add considerable stiffness. Problem really is that it's black and shiny when it's dry and it's black and shiny when it's wet with resin. Darned near impossible to tell when you have enough resin to wet out the cloth and not so much that it's floating in a pool of resin. Too much resin and you'll actually gain weight rather than lose any. Only reasonable way to lose weight with materials is using vacuum bagging.

Bill H.