Gel coat and a foil wing

[downunder]

Ok, back to the topic.

The gel coat wrinkled. BIG time. It actually ruined my almost brand new race fins!

It went trough the wax and the PTFE release film. Arghhhhh...How on Earth would I know?!

So basically, if you're making a mold (a cast) of something, say a foil mast or a wing to replicate, the Gel coat might dissolve any paintings on that part and that will result in massive irregularities on the mold. I'm thinking the epoxy might do the same, however it did not on this fins (already tried).

I'll add a pic soon.

[TheJoe]

Haha That does suck. Silicon for the win. But if you where just making a mold why not use some bagging material as a barrier and then fiberglass the mold?

[downunder]

Yeah, silicone might be ok.

Tried a thin barrier, the gelcoat wrinkled the barrier as well. Because getloat, as well as epoxy, gets worm when is curing it might "pull" whatever is under...

Interestingly enough, the gel coat did not react with white painting on a fin, just with the black one. Must be something in a colour. But that said, 8 layers of wax?! One would hope nothing goes through....

[TomW]

Are you using epoxy? If not and you are using polyester resin, the styrene in polyester is a solvent( with nasty voc) that will dissolve many types of paints.

[tkettlepoint]

get some high temp vacuum bag film make for polyester and stick that as your release.

[downunder]

The gelcoat is probably polyester based so that's why wrinkles happened. The imprint can be seen on the mold, however I did bite the bullet and poured epoxy in the mold today after slightly sanded and waxed. Will see how it goes.
I did flip the original fins, only a bit of white FS logo can be seen as 'half eaten' by the gelcoat.

[downunder]

Made a mold with around 15 MDF boards to get the winglets

The good news was we have 10 cuts free of charge and each cut after that is 20c (I think it was)! Didn't spend much time with cutting that Took about 1hr with jigsaw and belt sander to get a nice curved tips.

The vacuum test and now ready for making some wings:

tbc...

[tkettlepoint]

what carbon are you using there. nice big tow, will it form over the tight profiles

[downunder]

For the flat bottom it might

Cheers

D.

[downunder]

Post curing!

138g carbon, 90g epoxy.

Cutting it next weekend, can't wait!

Carbon 22/20mm by 1000mm tubes arrived today for a fuselage

Strut ready for infusion, core drilled, not decided yet about the plate or tuttle.