On Wed, 29 Oct 2014 10:10:39 -0400, Ed Huntress
wrote:

On Wed, 29 Oct 2014 18:46:24 +0700, John B. Slocomb
wrote:

On Wed, 29 Oct 2014 06:37:26 -0400, Ed Huntress
wrote:

snip

Anyway, your sarcasm was misplaced, as was Richard's. I don't know
what the hell he was talking about regarding boat paints. And when you
popped off about PFDs, it was clear that you don't sail where we sail.


I think Richard was probably referring to the fact that most, if not
all, small production fiberglass boats have the hull finished with gel
coat and a boat requiring paint would be one on which the gel coat had
deteriorated to a considerable degree.


Enjoy your sailing in S.E.A., John.

Cheers,

John B.

It's true that failing gel coats on lightly-built fiberglass boats may
reflect fatigue in the hull layup, but I don't see that as a reason to
make a blanket statement about it. Strongly-built boats, like a Boston
Whaler, Black Watch, Cape Dory or Stone Horse, will FAR outlast their
gel coats, and it has nothing to do with fatigue -- because those
boats generally don't fatigue.

In tropical countries it is quite common to see old fiberglass boats
with "chalky" finishes due to UV deterioration. While this may or may
not be a serious problem depends on the individual case but the
turning up of the nose at fiberglass boats that need paint is
certainly not a frivolous notion.

There's an entire industry dedicated to re-covering those boats. It
satarted with a spray-on replacement gel coat around 1960; progressed
a few years later to sprayed-on two-part epoxy; and, finally,
developed into re-coating with two-part polyurethanes, a lot like the
paint used on high-class custom cars.

Ed, I think in this case you really don't have all the facts. I've got
a good friend in the business and certainly he will re gel-coat your
boat for you, but it costs far more money than a two part polyurethane
paint job, which is not necessarily "similar to paint on high class
cars" as in many cases it is the same stuff. Dupont Imron comes to
mind.

And polyester gel coats are porous; they can get stained, or marked up
badly because of the way they were tied up at a dock.

If "Polyester gel coats" are porous then so is the whole hull as
"gel-coat" is commonly just polyester resin with an added pigment.

Gunner is more likely talking about rolling on a coat of house paint
g, but I don't get why Richard was so dismissive about painting a
boat. There are a lot of boats around here right now that are dry
docked or up on stilts, having their topsides painted at the same time
they're getting a new coat of bottom paint, before the weather gets
too cold. Most of them are fiberglass boats.

I suspect that it is because properly painting a deteriorated
gel-coated hull is an expensive proposition as to do a good job you
first need to remove the old gel-coat down to a smooth solid surface
and removing gel-coat is a pain in the butt and pains in the butt tend
to be expensive. Additionally, I suspect, it may well be extra costly
in the U.S. due to your environmental laws. I read somewhere that a
U.S. yard had refused to allow removing old copper bottom paint as
they said it would get them in trouble with the environmental people.
--
Cheers,

John B.