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Mac
 
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On Tue, 27 Jul 2004 02:58:19 +0000, Jason wrote:

A while back i asked about if it is okay to put fibreglass below the
waterline of my 28 foot mahogany lapstraked carver mariner.
Overwhelmingly the response was NO.

heres my next question,
Would just using epoxy to coat all wood surfaces of the hull be okay?
or does anyone see anything wrong with it? i need the quickest,
easiest way to make this boat waterproof so i can get a month out of
it this year at least. it has already been sanded down, just waiting
for my next move.

any help is appreciated.
thanks,
-Jason


I wouldn't normally think of epoxy as a waterproofing material, but I
don't know what kind of boat you have. Here is a quote from _The
Gougeon Brothers on Boat Construction_ (fourth edition)

"Most available plans for traditional small craft were drawn many
years before the development of modern resins. They rely on traditional
building techniques ... This sort of construction is not compatible
with our methods and, unfortunately, any attempt to blend old and new
will probably result in an unsuccessful hybrid." (p7)

The Gougeon brothers are the guys behind West System epoxy products.

So I would advise you to seal the boat in the same fashion (more or
less) in which it was designed to be sealed.

I do have a little experience with the aesthetics of applying epoxy to
wood. By itself, epoxy is a terrible varnish substitute. It looks great at
first, and it is relatively easy to get a nice glossy finish, but it
begins to go milky. It will do this very rapidly (in a few days) if it is
exposed to direct sunlight. Eventually, it will be kind of yellow and
almost opaque.

What you can do, however, is apply a few coats of epoxy first to get rapid
buildup and a nearly perfect finish with little or no sanding, then apply
a standard marine varnish afterwards. (You have to wet sand the epoxy
with very fine sandpaper prior to applying the varnish). I'm not sure how
this holds up over the course of decades, but it holds up pretty well for
interior jobs over the course of several years.

Practice on a piece of plywood before you do it on a piece you care about.
Also, some varnishes may attack the cured epoxy, so be sure to test the
exact combination before using it.

HTH

--Mac