A few questions: Is your friends mold male or female? In other
words, will the first layer of fiberglass applied be the inner skin of
the finished hull (male), or the outer skin (female)? If the former,
gelcoat is not an option; you'll have to fill-fair the hull, then use
an epoxy primer over which you'll apply a compatible paint.

In female molds (on the other hand), gelcoat is the first 'foreign
substance' applied to the mold (release agent assumed). This is
almost always followed by a layer of mat, to avoid the visual
'print-through' of the heavier woven materials in the laminate. Mat
must be applied using polyester / vinylester resin (which contain
styrene, which breaks down the binders in the mat). Here's the
problem: You're proposing an epoxy laminate; it's very difficult to
properly 'tie' the polyester/vinylester layer of the laminate to the
epoxy layer.

You might check out:
http://www.wessex-resins.com/proset/gelcoats.html
looking specifically at the 'epoxy gelcoat' descriptions and
procedures.

Good luck!

MW
Los Angeles


I am just getting started building a new sailboat, I will be using a
friends molds. I am using epoxy and glass but we wondering what people
thought about various approaches to painting/gel coating it. What
should I do? What are some positives an negatives?

Thanks for any advice