Carbon fiber Prepreg

[way2ski]

Does anyone have experience with carbon fiber prepreg material? I'm a newbe, so I was wondering what thickness and how many layers might be required. Also twill vs straight fabic. I'm thinking or two reverse layers of twill.

[twizzstyle]

Depends on what you're using it for. Aesthetics? Use the twill.

If you're using it for actual added stiffness/strength, use only unidirectional. Any fibers running laterally (side-to-side on the ski) will be doing virtually nothing but adding weight.

It also needs to be kept in a freezer, and needs to be compatible with whatever resin you are using for the rest of your layup. And it's crazy expensive.

(what's a reverse layer?)

[way2ski]

I'm familiar with aerospace radomes for antennas. They use a bias twill ply layup, but they alternate the layup so the bias is reversed on each layer. Good point about unidirectional fibers for longitudinal flex, but they don't provide as much torsional rigidity bias ply- I think

[twizzstyle]

Diagonal fibers will provide torsional stiffness. Lateral fibers WILL NOT! That is why triax is the most commonly used composite for skis and snowboards, you get the bending stiffness from the longitudinal fibers, and the torsional stiffness from the diagonals. Lateral fibers would provide lateral bending stiffness, but the ski is so narrow for it's thickness, you get negligible bending (at least in a ski, it might be more appropriate in a snowboard)

[artski]

You may want to check on whether you need high heat(350 plus f) to get it to bond