Why not use epoxy? After it has cured, practically nothing will
react with it. You don't mention which type of resin you are using
for the fiberglass mold, but I'll guess that it's polyester rather
than epoxy. The solvents used with polyester resin are far more
reactive than the epoxies.

Jim - AMA 501383

Ivan wrote:
I'm currently working on a project were I'm making a mould of a
spherical garden ornament. The garden ornament is the plug, I filled,
sanded, painted and smoothed it, then I applied several layers of
release wax and then PVA. When I applied the fibreglass it caused the
paint to soften and blister, and it peals away when I try to remove
the fibreglass mould.

I have tried using car bodywork repair paint, the high build type
that is easy to sand, I also tried ordinary household vinyl emulsion.
Both of these have caused the same problem.

Could anyone tell me what type of paint won't react with polyester
resin, that I can obtain in the UK?

Other postings have mentioned Duratec but we don't seem to get that
in the UK, is there a similar product I can get here?

Others have mentioned polyurethane or polyester paint. Can I get
these in B&Q or Halfords or online somewhere? Is melamine paint
viable?

Cheers for the help.

Ivan