moulding carbon fibre

[haggis]

Hi guys

Im planning on making a mould of the inside of my hull using carbon fibre.

this is so i can mount the motor mount to it and strengthen the inside of the hull.

does the surface have to be smooth on the hull or can i just use pva mould release stuff?

[JIM MARCUM]

Why not just epoxy the carbon fiber cloth directly to the hull? Seems like a lot of extra work to make a mold, lay the CF, and then re-epoxy it to the hull. Am I missing something here? JIM

[sft2]

I agree with Jim, I can't think of a compelling reason to make a mold of the inside of a hull (ok, I can, but it's a pretty far out way of doing things). That said, if you want to actually be able to get the carbon out of the hull, the surface needs to be extremely smooth with no undercuts, then waxed multiple times, and a couple of coats of PVA over that.

[haggis]

point taken. i just thought i could make a neater job of whole thing if it was out of the boat.

have you guys got any tips on securing the motor mount to the CF?

ill be using 30 min Zap! epoxy and a basic L shaped aluminium motor mount

[sft2]

Drill a few holes in the mount, scuff it up with 60 grit sandpaper, degrease, glue it down in the right spot making sure the epoxy oozes through the holes, and glass it down with some light glass or carbon. I use West System epoxy for almost everything, which is much thinner than Zap or similar, so if you're using something like that you'll need to add some milled fiber or similar thickener to get a strong joint. Don't let the epoxy fully cure before adding the cloth over the top. If it's still sticky you'll get a chemical bond between everything and it'll be much stronger.