Bonasa wrote:
Hi,

Once again I need to draw on the wisdom of this group hoping for an
explanation or clarification. I posted earlier regarding the repair of an
impact hole in a fiberglass sailboat hull. I'm using the Don Casey boook
"Sailboat Hull & Deck Repair" and have run into conflicting/confusing
information.

In the book, he states that epoxy resin should always be used for repair
because it creates a stronger bond than polyester resin. He then goes on to
state that the only time not to use epoxy is when using polyester gelcoat.
Okay, so far so good.

Then in the section titled "Impact Damage" which is what I'm following, the
first step in the actual repair is to lay up a piece of acrylic on the
outside of the hull and apply a 20 mil coat of gelcoat from the interior up
against the acrylic, then start laying up the fiberglass layers on top of
the gelcoat.

This is a large repair (4' long by approx 4 " h) and strength is the primary
importance to me, so it would seem epoxy is what I would want to use. But
following those directions I have to use polyester resin to have the
fiberglass adhere to the first gelcoat layer. Is there something I can use
to substitute for the gelcoat that will allow me to use epoxy? Any
suggestions? Is there some kind of paint that will have a thick enough
consistency to use on a nearly vertical surface? Using epoxy resin for the
strength is more important to me than what the finish looks like, it'll be
underwater so the cosmetic aspect doesn't matter much to me.

Thank you for any help and suggestions on how to handle this part. Also, one
person requested I keep posting the progress of this disaste....I meqan
project. I'm putting together a web site of sorts to show the progress.
www.geocities.com/lokisdad1026 if you're interested. I have little time and
no knowledge of web page design so don't expect much but maybe it'll help
someone so I'll do the best I can there.

Mike


Aw, lay a coat or two of poly glass on the outside to accept the
matching gel coat. Then complete the repair from the inside with
epoxy, if having a hard spot at that point doesn't bother you.

Epoxy is so strong that it makes the surrounding polyglass look weak
by comparison, but it isn't. Polyglass will stick to properly
cleaned and toothed polyglass well enough that the actual benefit
from using epoxy is not really practically useful, or cost
effective. Overbuild the inner part if it makes you feel safer.

Feather the edges out on the inside and equally on the out. 10:1 is
plenty.

Terry K