I've dug out a lot of soggy foam too. Undoubtably it was 2 part foam, but
even so, it soaked up water , so I expect there may not be much difference.
You just keep it dry 'til you need the floatation, and hope you won't need
it to float but so long !

"Jason" wrote in message
...
I've worked on a few boats that had saturated floatation foam. The boat
was
not submerged, just exposed to normal bilgewater or rain water over the
years. The foam sure didn't look like it would float in its saturated
condition, it was extremely heavy. I threw out 700 lbs of it from under
the
floor of a 20 open powerboat.

Just something to keep in mind.

Jason


"Roger Derby" wrote in message
nk.net...
"over time" ??? How much time?

It is a safety issue, but most or us aren't going to spend weeks or
months
depending on it.

Sometimes the difference is not in the material but in the documentation
and "approvals."

Roger

http://home.earthlink.net/~derbyrm

"Brian Nystrom" wrote in message
news:E9xKe.5643$lK2.4843@trndny01...

keith wrote:
Just a quick question. Is polyurethane buoyancy/flotation foam in
aerosols the same as the polyurethane foam sold at builders merchants
for sealing voids and cracks etc? The reason that I ask is that my
local
chandlery has aerosol foam that
looks about the same if you read the ingredients etc on the tin, but
the builders is cheaper.

Floatation foam is generally a two-part foam specifically made to be
waterproof. Most foams used in construction will absorb water over
time.
Considering that buoyancy is a safety issue, it doesn't make sense to
risk using sub-standard or inappropriate products.