Stiffening Fiberglass

I’m trying to cut pieces of CF to make a fin. They have to fit the mold fairly well and the stuff won’t sit still to cut it. Is there some sizing or starch or something that will let me cut nice pieces and not affect the strength of the final product. It can be pretty stiff because it doesn’t have to form around curves of anything.

You could e-mail Graham Herbert on Hornby Isl. and ask him. He has just made some fins.

To stop your dry reinforcement from fraying / distorting while cutting, surround the pattern with lines of masking tape ( a little bigger than you need of course), then chop with yer sizzors, halfway (middle line) through the tape. Same as when cutting from a roll…masking tape line across, cut it in the middle, leaving a half of mask, to hold the edges from fraying.

I have heard the expert guys in r/c glider and sailplane forums talking about using 3M Super 77 spray glue. It is a fine mist, multi-purpose contact adhesive usually used for plastics, paper, foils, foams, metals, etc.

I use both tape and 3m77 where needed.
A light mist of 3m77 is great if your moving big or small pieces around.
Carbon is so exspensive its horrifying to have it come apart before your eyes.

And the 3M77 doesn’t affect the wetting out or strength?

That spray, and “Airtack” are commonly used for lay-ups. It’s a great third hand in Infusion-type jobs as well. Doesn’t affect anything in the lay-ups.