hpeer wrote in news:49be353d$0$19669
:

Actually most steel boats are insulated with foam above the water line.
This is the commercial variant of the foam not the minimially
expanding Great Stuff.

However you make a good point for the repairs and I would only do it as
an immediate expedient to stop a leak until I could address it properly.



Someone I know bought a used pickup truck that looked brand new.

It had a professionally-installed, sprayed-in plastic bedliner that was
really expensive in it.

The first time he got it in the shop, he helped himself to the bottom of it
while it was up on the rack at his fav garage.

Looking around for anything wrong, he was STUNNED to see the BOTTOM OF THE
BEDLINER in big holes of rust that used to be the truck's pickup bed!
Water had gotten between this bedliner sprayed on it and the steel, eating
away first the paint, then the hull....just like it would in a steel hulled
boat.

It looked great from the top, of course, as the plastic covered up the rust
holes and seems to support the load. Maybe Ford shoulda made the whole bed
out of plastic!