If the core has gotten wet and mushy, there's no alternative but to replace
it.
The decision of whether to remove the top or bottom skin is next.
A glass job like this is only practical if working in a downward direction,
so this is generally done by removing the upper skin. However, if it really
is practical to turn the boat upside down and if there's not a molded liner,
then maybe working from the inside might work.
In any case, get the booklet from West System (their #002-550) "Fiberglass
Boat Repair & Maintenance". they describe the methods for this job.
If you remove the top skin, you need to repair the nonskid, either by
fairing the surface flat and using nonskid paint or by reproducing the
nonskid pattern. There's an article on how to repair nonskid pattern in the
Winter 2004 copy of Epoxyworks magazine. It's on the West System site.
This is fussy work and may be more work than the boat deserves.


"Michiel" wrote in message
...
Hello,

I'm looking for a little bit of advise. This is more boat repair then
boat building, but I'm figuring you guys here would have the right
kind of knowledge.

At the beginning of the summer I bought a trailerable fiberglass
minicruiser (a 1983 Gloucester 20). When it rained in the fall I found
there were some leaks into the interior and I found out that the
central part of the deck (not all of it) is balsa cored and one side
of this is saturated with water. All of it has some delamination.

I drilled some holes from the inside and found that the port side is
wet and some of the balsa is dark and the starboard side is mostly
dry. The water may have come in at holes for deck hardware and some
cracks in the gelcoat, one of them spiderweb shaped. As an extra piece
of information, the mast rests on a higher area of the deck which
seems to have a thicker core (probably not balsa) which is dry.

I want to stop the water from getting in and I'm also concerned that
the delamination will cause the gelcoat to flex more and thus crack
more. It's been on my mind and I've thought of the following options:

1 - leave it be. put deck hardware back on sealing carefully with
polysulfide or 3M 4200. Perhaps drill a large number of holes in the
inner skin so the balsa can dry out.

2 - cut out inner skin, scrape out old balsa core and glue down new
balsa or plastic core and then cover this with polyester and
fiberglass.

3 - cut out inner skin, scape out old core and add multiple layers of
fiberglass and polyester, building up until the deck is nice and
stiff.

I'm strongly leaning toward option 3, but also considering 1.

Let me know what you think, please!


Thank you,

Michiel van Wessem