On Aug 27, 1:37*pm, Eric Greenwell wrote:
wrote:

Another option could be to skip the whole gelcoat thing and do the
lamination of epoxy/glass/carbon directly in the mold and accept that
it will need pinhole/prime/fill and then paint. You would avoid the
time delay failure mode that gelcoat finishes have inherent to them.
They all fail- its only a matter of time till the gelcoat comes off in
sheets or chips.

It's all about the duration, though:

Time = 5 years = angry owner
Time = 50 years = happy owner(s)

Do the factories offering polyurethane paint as an option to gel coat
still use a thin layer gel coat? How much does that method extend the
life of the gel coat?

--
Eric Greenwell - Washington State, USA
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The painted gliders still come out of the mold with gelcoat. It gives
them something to sand and provide basis for finish.
Life isn't known yet because the aren't that many out there with
original PU finishes. It has only been commonly available, as far as I
know, for maybe 5 yrs. If you can keep moisture and UV away from it, I
would expect gelcoat to last quite a while, certainly longer than
"natural" gelcoat.
All this said, we have a Std Libelle in our club which is over 35 yr
old and the finish on the wings(original) is still excellent.
We also have an ASK-21 which is about 25 yr old which I expect we will
be able to take the gelcoat off with a chisel(don't ask) in chunks.