Chuck Duchon wrote:

Do you think the stuff specifically designed for marine use is open cell? I
know it's pricey at $70.00 or so for a qt but I was under the assumption
that it was closed cell and therefore waterproof.

Good question... I only know about some experiments with the two
component expanding foam in kayaks in my old student paddling club that
went horribly wrong. In part because the surface layer was initially
waterproof and a little bit flexible but then started to crack after a
while, soaking up water, and also because of the heat of the chemical
reaction slightly warping the hull.

My other concern is removal: once you want to change it, or if you'd
like to sell the boat, can you still get it out?

Personally, I'd rather pay the 30 euro's or so that a giant block of
minicell costs (around here, that is) and cut it to the size and shape
that you need, than run the risk of using 70US$ foam and maybe getting
any of the three mentioned issues.

I've been playing with minicell and contact glue quite a bit over the
last couple of years, and I cut a perfectly fitting footbrace for my
latest kayak (Bliss Stick Flip Stick) out of minicell as well. That took
an hour or two, but it stays in my boat when I want it to (it's glued
in), comes out if need be and it fits my feet well.

--
Wilko van den Bergh wilko(a@t dse d.o.t)nl
Eindhoven The Netherlands Europe
Look at the possibilities, don't worry about the limitations.
http://wilko.webzone.ru/