I will shortly be making a carbon/kevlar fuel tank for my competition bike, and cant decide whether or not to have a poly gel coat finish or to paint.
Probably be better to paint the finished tank, but wonder if anyone has had any experience using epoxy over poly gel coats?
I had no luck with poly gelcoat with epoxy resin for the layup( if thats what your talking about) The gel coat never realy cures in the mold so the epoxy only had semi cured gel coat to stick to. Im sure you can make something work but I would say paint it.
If you sprayed the mold with the gelcoat and get it fully cured the scuff it before the lay up maybe, but I have not done that myself.
I was going to use wax additive in the gel-coat so it cured fully, then sand before laying up using epoxy.
Why not use an epoxy surface coat instead of Poly gelcoat?
Main reason is cost…this being a one off for my own bike. I wont be needing much material, and here in the UK things like epoxy surface coat are generally pretty difficult to find, and have to be bought in quite large minimum amounts.
you can paint Duratec tint base over the “sticky” gel-coat and the epoxy will stick to that no problems,
we also brush our regular laminating epoxy (with fastest Hardener)( but never in High Humidity) into the mould, let it cure overnight(def not postcure) and lay up the next morning
You need to use a regular carnauba wax like Ceara so the “gelcoat” doesn’t fisheye and/or drain too much