On Sun, 22 Feb 2004 11:19:10 +0000, Peter Clinch
wrote:

Ewan Scott wrote:

Two pack fillers are NOT waterproof which is why car bodies repaires
with filler end up with rust around the edges just before the filing
falls out :-)

Some may not be, some I think are. The one I used specifies boat
repairs as one of its jobs and was sold to me on recommendation by a
specialist fibreglass boat builder. Mileage varies...

I'm not a chemist, but I did once research the commercially available
fillers on the market and at the time - three years ago, there were
none that were waterproof. They all use a filler material to bulk out
the mix, usually talc - which absorbs water.

It may be that there are some specialist fillers but you would need to
be sure that what you were buying was the right one.

Ewan Scott