Spray Foam for Floatation?

On Thu, 22 Nov 2007 17:04:33 GMT, – Colonel – <nobody.RemoveThis@fishing.net>
wrote:

>I need to fill in some missing foam under the front seat of an aluminum
>john boat. Does anyone know if I can use that "Great Stuff" spray foam
>or whatever it's called that they sell at Home Depot, etc. for use in
>houses?
>
>I believe that stuff is a closed-cell foam. Has anyone used it in this
>application and is it appropriate?
>
>Thanks.
>

The only relevant factoid I have is that people who used foam
polurethane aerosils under a glass skin on homebuild aircraft were
disconcerted to find that the stuff swelled again on a hot day,
messing with their faired curves.

Brian Whatcott Altus OK
 >> Stay informed about: Spray Foam for Floatation? 

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 >> Stay informed about: Spray Foam for Floatation? 

On Nov 22, 12:04 pm, - Colonel - <nob....RemoveThis@fishing.net> wrote:
> I need to fill in some missing foam under the front seat of an aluminum
> john boat. Does anyone know if I can use that "Great Stuff" spray foam
> or whatever it's called that they sell at Home Depot, etc. for use in
> houses?
>
> I believe that stuff is a closed-cell foam. Has anyone used it in this
> application and is it appropriate?
>
> Thanks.

I used it in a couple of cheap canoes. It works ok, and if shot in
right, is pretty waterproof. Only downside is it is a real mess and
gets yellow and brittle after a few months. You can however shape it
easily, and paint over it too. So if it is just a knock around boat,
and a small space (I would not do a whole boat with it) I say go ahead
and use it. Here is a tip too. You can take some chunks of old foam,
even open cell, and use it for filler as long as the chunks are
surrounded by the great stuff. If you have a bigger area, do the sides
and bottom with the GS, lay the chunks in the cavity, and cover with
more GS... I think you get it. Also, do not fill a whole area at one
time, use the stuff in layers and leave a few minutes between apps for
each to puff up...
 >> Stay informed about: Spray Foam for Floatation? 

Don't mess with Great Stuff in your boat. Great Stuff requires
moisture from the air to expand and cure. If filling a large cavity
the Stuff in the middle won't get enough exposure to the air to cure,
and will remain uncured, and there is a potential that under the right
conditions, it can later get enough moisture to expand at the worst
possible time. There's no reason to use it, except that it is
available at the local Wal-Mart. It won't be cheaper than 2 part
foam. It will take longer to apply. Go to http://www.raka.com or
http://www.uscomposites.com and buy some of the 2lb/ ft3 two part foam
instead, they'll have it out to you in a couple of days and you can do
your boat right.

Ed.
 >> Stay informed about: Spray Foam for Floatation?