Flexible closed-cell foam - pourable

[kach22i]

I found a local source of closed cell foam, in rolled sheet of 60" wide and 3/4" thick, I forget how long, but the log is 36" in diameter. It's about $500 a roll with shipping, that seems expensive to me. If you want a 4' x 8' sheet it's over $100 closer to $200, and there are more than five sheets in a continuous roll.

I've read about two-part liquid, expanding "rigid" urethane foam which is closed cell, pourable foam, and will resist the absorption of water.

QUESTION
Is there such a thing as two-part liquid, expanding flexible urethane foam which is a closed cell, pourable foam, and will resist the absorption of water?

The lighter and lower the density the better for my application.

This is a home brew design/experiment, so funding is very limited.

NOTE: I've been looking into this topic for a while now and getting nowhere. And what do you know, just found this:

http://www.rubbermoldcompounds.com/s...s-supplies.htm
FlexFoam-iT!

The FlexFoam-iT! Series of flexible foams come in 3, 5 & 10 lb. densities. They are two part flexible foams that are strong, versatile and easy to use. A+B mixture expands many times its original volume – cures quickly. Vibrant colors are achieved by adding color tints. FlexFoam-iT! Products are ideal for many arts & crafts, special effects and industrial applications.

..............now I just have to poke around and see if it's open or closed cell.

I could use any information or suggestions on where else to look.

[kach22i]

I called up US Composites, best time to call in early in the morning. The guy on the phone was honest and said he was not the best person there to talk to (I called late in the day). He had me going - said they have "flexible foam", but closer review of their site shows only pourable "rigid" foram. Guess it's flexible until it cures, don't know what he was thinking.

Anyway 2lb foam is the lightest and cheapest.

http://www.uscomposites.com/faq_foam.html

14. Is this foam water resistant?

Yes, but with the following caveat. The foams that we sell are considered closed-cell, which means that each cell that makes up the foam structure is completely closed off from surrounding cells which prevents it from acting like a sponge. It is completely safe for this foam to be in contact with water for hours/days/weeks and even months with no adverse effects. However, it should never be submerged in contact with water permanently. Over a period of years the water contact can begin to soften the foam and cause it to lose its closed-cell status. This foam is designed primarily to be used as an insurance policy in case of damage/holes that could cause a vessel to lose buoyancy. Pinhole sized openings would essentially have no effect on the foam since the amount of exposure is so minimal but you should always make repairs as soon as possible to keep the foam effectiveness as good as possible. This will be the case will all after market closed-cell polyurethane foams and even manufacturer installed foams.