T&T: Filling pockets behind stringers in older trawler

[Michael Bragg]

Hi again,

Just wanted to thank the list for the suggestions about filling
those pockets. I went with the spray-foam to fill the bulk of the space, then
used a knife to cut the tops off of the foam humps, then sanded all of it flat
(I didn't know you could sand that stuff with a belt sander...works great!),
then I put a layer of fiberglass strand re-enforced polyester filler (aka:
Monkee-s*it) over it for a smooth and strong cap. This is where I am at now. I
found that a thin cap was better at first, as thicker amounts of filler seemed
to sag the foam either from weight, chemical reaction, or heat. After a thin
cap was hard, it was easy to rasp it and apply a thicker layer to the cap.
I was tempted to just cut plywood to fit as caps, but I didn't want an open
void underneath. The foam will at least displace any water that might get by
my cap.

My plan is to use some CPES to seal the filler nicely (I love this
stuff, and use it everywhere, but the fumes are intense and requires working
quickly with respirator - then vacating for a day or two, depending on how
much you used), then lay some new polyester FRP over the filler and blend it
into the stringers and hull. Then one or two more coats of CPES to fill the
pores. I'll probably leave it unpainted for a few weeks to check for cracking
or shrinkage. Then primer and paint. It's a lot of work, but I'm happy with
the way it's going, and it's not yet emptied my pockets. :) 

Thanks for the
help.

- Michael