Gelcoat repair

Hi

I have repaired some old skin fitting holes above the waterline with polyester resin and csm, but some of them have finished maybe just a bit too deep for gelcoat I think. I intend on using an epoxy primer and 2 part polyurethane on the topsides anyway, but not until the weather improves in springtime.
So my questions are:

1. How thick can I go using gelcoat filler without the risk of being too brittle or shrinkage?

2. Could I go thicker using epoxy with chop strands/q-cells/low density filler etc?

3. Would epoxy be uv stable by adding such fillers?

 

1. You can't go very thick with gel coat, or putty made from gel coat when it covers a larger area, filling a pit or hole you can get away with it being slightly thicker. It also depends on the amount of stress and flex the area is subjected to.

2. Epoxy with glass fibers can be built up much thicker.

3. Nothing will make the epoxy UV resistant other than a coat of paint.

 

Thanks ondarvr, I will look tomorrow at the best course of action