"DSK" wrote in message
.. .
Why? What is "fiberglassing over the hole" vulnerable to? You still
haven't explained that part. And it's certainly not prohibitively
expensive...

It's not vulnerable to much unless there is impact and flexing. I
wouldn't want to just fill the hole on a solid layup (which my boat
is) as there isn't much to hold the patch in. The fiberglass should
be tapered back so there is a good, long scarf for bonding. You're
right that it wouldn't be expensive to do yourself but I'm thinking
yard time (after all, my time is worth something too and unenjoyable
jobs like grinding fiberglass don't have their own rewards). By the
time it is ground, filled, faired, and re-painted, it will cost a bit
either in other things you didn't get done or out of the checkbook.

With a cored hull, you can and should dig out as much core as you can
reach to seal if from the water. This will create a good mechanical
as well as adhesive connection since the patch will extend between the
skins.

The cap and fill will last as long and reliably (actually more so due
to the watertight fill) than the rest of the through hull plumbing.
That's good enough for me. Getting plastic through hulls, especially
the ones near the waterline that can freeze, replaced with bronze is a
much more important issue.

--

Roger Long