Painting/gel coating over Epoxy
 

Hello Everybody,

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

Painting/gel coating over Epoxy
 

If you're using 2-part marine epoxy, you have to paint it or clear coat
it. Otherwise UV rays will break down the epoxy over time.

--
Matt Langenfeld
JEM Watercraft
http://jem.e-boat.net/

et2piei wrote:
Hello Everybody,

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

Painting/gel coating over Epoxy
 

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

Painting/gel coating over Epoxy
 

Thanks for the advice.

I am using a female mold, the first layer will be a thin veil, it can
be used with epoxy, I have check this with the manufacturer. I will
not be using a wooven cloth it will be a biaxial, but yes print
through perhaps will be a problem. I was planning on just epoxy
painting it after I pulled it from the mold but many people tell me
that the epoxy will not release as easily as using a gel coat. So the
problem for me might be a way to be assured that I can get the hull to
pop from the mold. I will check out the link, for the epoxy gel coat,
thank you very much.

Painting/gel coating over Epoxy
 

mike worrall wrote:

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).

Epoxy compatible mat is available. I've used it in a few repairs.