Do you think any material other than G10 will hold up to the stresses put on fins this length? Lamborghini and Callaway are pioneering a new carbon moulding teqnuqie called "Forged Carbon" which is basically chopped up carbon material that is pressed into a mould. It allows for much more complex shapes and is cheaper to produce. Similar to your black hairball goo. I don't see this process being much stronger the traditional carbon layup method though.
Not sure about "forged carbon" (patented in the games and toys..... not in materials
but Short strand injection molded composites aren't anything new, However they require equipment that will NEVER be present in my garage. And it's known they are NOT stonger than a lay up due to the discontinuities in the fiber and tendency for pull out if the length is not long enough.
However when you say "fins this length", figure your talking racing fins. If I were to tackle these I'd certainly overlay whatever I made with unidirectional carbon for structural stiffness. I like the idea of using a mold cause I don't trust myself sanding anything by hand well or consistently let alone aerofoils.
Beware the exothermy and thixotropy escalation of carbon kitty hair for molding.
Personally I found CF made normal room temp laminating resins (west 105, RR 2000 etc) unmanageable for pouring into one part kite fin molds before it made them strong.
Your mileage may vary, good luck!
Re Exotherm, thank you VERY good reminder.... I needed it....
Was hoping some cabonsil (or like) could help keep the kitty hair suspended as it warms up and gets runny.
Played with hair and epoxy when podding inserts and know it'll never pour it. Was thinking the "kitty hair" for flat sided outside surf fins where I can "scrape" it into the mold and squeeze out excess. For 2 piece molds was gunna try making it nice and thick scrape it in each side add a bit extra, slap the two molds together and squeeze out any excess into the pour holes. but at this point I still gotta work on the mold release.
Just playin right now. see if something works.
More of a learning exercise than a real time/cost savings for now.
but might make my money back if I ever make a set of race fins.
I can't imagine these big knives lasting long the way I ride, I COULD be more careful but that would cut into my fun.