Hi Ivan,
I feel for you. It's frustrating isn't it? Anyhow, here's what you should
do next time -

Use ONLY Nitro-cellulose Lacquer as the final coat on your plug. I've heard
that Acrylic Lacquer is also ok but I've never used it. In the colonys, its
marketed as ICI (Imperial Chemical Industry) DUCO. Apply Duco in thin coats
letting each coat flash off before the next coat (abt 3 mins in the tropics)
then one thicker flow coat. Then its done. Let the paint harden for at
least a few days until there is absolutely no smell of thinner when you put
your nose to the plug. Then and only then do you apply wax.
If you're feeling rich, you can also use epoxy paint and most 2 pack paints
but I don't have personal experience with these. But I dare say that a
harder paint will make the demoulding easier since Duco is somewhat softer
and MAY deform slightly under mould shrinkage. But I've not had major
problems with duco. But you also must make sure that there are no soft
spots under the paint or the mould will shrink into those soft spots making
the mold surface less tahn perfect.

email me directly if you have more questions.

cheers
Arnold

Ivan wrote in message
om...
SNIP
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.