Spray in foam - foam adhesive

[anonymous]

This is a simple question for some of you guys out in submarine land. Is the spray in foam insulation/adhesive closed cell or open cell when it cures? Is it OK for submarines or will it absorb water like a sponge?

[wayne frey]

I read an article where

I read an article where Greg Sharpe used a spray in foam in his Beluga. Coincedintal you post this, as I would like to know as well.
In talking to Tom Spettel last weekend, he told me about coating his foam,which made it more predicatable to trim. I would like to find a "spray in" to try now or maybe on a later project that has the properties of closed cell foam.
Who has tried this and what do you think of the result vs. conventional foam setup?

[tmsmalley]

Great question. Since Bob the

Great question. Since Bob the Builder, the SC webmaster knows Mr. Sharpe, maybe he can find out for us?

[bob the builder]

I should be seeing Greg

I should be seeing Greg this week sometime when we do the final tweaking of my Nautilus' trim. After that we have a sub run planned for this weekend at Thetis Lake. I'll be sure to ask him.

If I remember, however, he doesn't use the "off the shelf" spray foam, but rather a two part mixture that foams when it cures. It looks pretty much the same, but from what I could tell, the bubbles in the foam were far more uniform than the spray stuff.

I'll let you guys know after I find out...

[tmsmalley]

Thanks Bob! Brand names and

Thanks Bob! Brand names and suppliers would be great too.
Tim

[d manley]

Please, please please don’t even

Please, please please don’t even think about using that stuff! It is unstable after cure and I know from personal experience that it can deflate so to speak and cause a buoyant sub to sink and maybe get lost!
If you can’t resist the urge to cast your foam, then use an industrial 2-part foam and then cover with polyester resin or epoxy.
This type of foam is much more stable especially when used in a closed mold.
I hope this helps or even saves someone.

Dave Manley.

[anonymous]

Dave,
Bravo Zulu...The LAST thing that

Dave,
Bravo Zulu...The LAST thing that any of us need is to put something in the boat that is akin to a ticking time bomb. Thanks for a straight forward answer to the question.
Chuck

[uss silversides]

The same doesn't happen to

The same doesn't happen to "blue foam", I hope?
Jon

[tom spettel]

The blue or pink foam

The blue or pink foam you buy at home depot wont melt if you use epoxy resin. I used west systems epoxy with a little
coloring (black) coated the foam and layed them out on a sheet of wax paper and let cure.
Tom

[tmsmalley]

Greg has been around quite

Greg has been around quite awhile and really knows his stuff so I'm assuming he uses the "industrial" two part closed cell foam. I would still like to find the brand name and a supplier when Bob Martin sees him next.

[bob the builder]

I'm finishing tweaking my linkages

I'm finishing tweaking my linkages tonight and am hoping to do final testing with Greg tomorrow night.

What Dave says makes sense to me. I've used the spray-in foam on my 16th century galleon to fill all of the empty voids (no way she'll ever sink!), and I noticed that it was pretty easy to crush the foam with my fingers.

For a submarine operating at depth, I'd imaging that the water pressure could do the same thing, resulting in loss of bouyancy and possible.... sinking!

[uss silversides]

Tom-
What I actually meant

Tom-
What I actually meant was does that blue or pink stuff absorb water?

[carcharadon]

I use Home Depot great

I use Home Depot great stuff insulating foam in my subs. And yes it will compress to some degree. So I purposely send my subs to the bottom (approximately 20 -- 30 ft.). After a couple runs to the bottom the waterline is pretty much stable and after that I don't have to mess with it. If the waterline is still too high I simply remove foam.

And yes it will absorb some water but not like a sponge. It's a slow but slight saturation over the course of say a two-hour outing. It usually takes a day or two for the foam to dry out. If my waterline is slightly high to start I know that after a while it will settle down some due to this saturation characteristic.

I would like to know about a better foam though more resistant to saturation and compression and where available.

[bob the builder]

Just got back today from

Just got back today from my Nautilus' first voyage... more on that tomorrow...

Greg told me that Tim may have more info on what Greg uses (I guess Tim e-mailed Greg directly). We can wait for particulars when Tim gets the chance to write here.

From what Greg told me, he uses blue foam almost exclusively unless space is very short. Only then will he use a two part urethane expanding foam to fill any voids. Apparently it's also resistant to polyester resins....

[tmsmalley]

Nope, haven't heard from Greg

Nope, haven't heard from Greg yet. I will let you know when I do.
Tim