On Thu, 25 Mar 2010 22:54:40 -0500, cavelamb
wrote:

Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester. Feather the gouge out and pack it with epoxy saturated
mat. If you are worried about osmosis, after you have made your
repairs grind the entire underwater area down to a good solid surface
and roll on two coats of epoxy. Put the first coat on and let it set
up until it isn't sticky but you can still mark it with your finger
and then roll on the second coat. After the second coat sets up, but
still not hard, roll on a coat of epoxy high build primer and leave it
for a day or so.

If you don't wait long enough after the first coat of epoxy the second
coat will be very heavy as you have to slop it onto a sticky surface
and if you paint the primer too soon it will craze - tiny cracks all
over the place. The reason for all this hoopdi-do is that if you let
the usual epoxy set hard it will have an oily film on it called "amine
blush" and then you have to wash the whole thing clean, let it dry,
wipe it with thinner, and repaint.

Finish sand and two coats of two part polyurethane. You'll be good
for ten years or so.... However it is more costly then polyester and
barn paint.

Cheers,

Bruce


I gotta say, Bruce, about the only thing that could be done beyond that
it a couple of layers of new glass over the entire underwater hull.
A close out layer that seals off all the possible cracks and crevasses from
water incursion.

Not that such would be economically feasible...

Richard


Yes, and I've seen a number of boats that were treated that way. Grind
off all the gel coat and let it set and dry for about half a year.
Then fair the hull and cover it with one layer of glass cloth. It is
expensive.

Over here the labor costs aren't expensive and even materials aren't
too bad but the yard rent is going to get you. All the yards, except
one hard stand area are commercial yards and charge commercial rates
for space. You might get a better rate for a six month stay if you
picked a period when the yard wasn't busy, but that is usually in the
rainy season... And, I've always wondered how much drying out goes on
when humidity is in the 80s and 90s?

Cheers,

Bruce