4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit)

This works great and made a nice, firm filler that I needed for a place on my kayak. It was easily sand-able and paintable. It is firmer/stiffer than the spray foam you buy in cans at the home improvement store. Just be aware that the directions are a bit off. In the video we watched online, it looked as if it foamed up instantly, and the directions said to count a number of seconds and no more before pouring. Our experience was that it took a bit longer for it to foam up, and we wasted some that poured through some holes in the cavity we were trying to fill. I would say an extra 10-15 seconds would have worked better.

I purchased this product to secure a fuel tank in a boat. It worked perfectly. I carefully followed the instructions, adding part A to part B (not the other way around), working in an ambient temperature of about 70 degrees Fahrenheit. It expanded slowly over a few minutes and did not "explode" as described by others. The instructions emphasize the mixing order, and I suspect that is the key to avoiding disaster.

works well with a great expansion rate.

I created a rear wing which was hollow and needed to strong as it is active and used as an air brake so I needed to fill it with foam. The 4 pound foam was perfect but calculating the internal volume was difficult. To be sure I wasn't going to come up short I added a little extra and did two pours. Because of the shape I couldn't see where the first ended so I proceeded to do the second pour. As soon as I saw it I had like 2 seconds before it over flowed. All good as I planned for this and could just cut the excess off. So be warned and prepared if you mixed too much. It sticks to everything and there is no stopping it. My wing now is as hard as a rock and strong so it worked well for me.

Instructions were unclear and also we're not included so I started off slow poured some in at equal amounts of both solutions with nothing happening so I poured more started to mix and get thick but still barely forming so I figured I'd put all of it into a four gallon bucket started to see it mix more turned around for about ten seconds to prep the area on the wall to fill and I turn back around and it's all just a solid bucket of useless hard unmailable foam no choice at this point but to throw it all away wouldn't recommend if you plan to shape it in any way shape or form

Needs to be room temperature to expand right cold temperatures mean less expansion. works well

Used for taxidermy purposes. It's a denser foam that does not expand as much as the lighter weight foams, but it has been great for form alterations etc Might be a waste to use for habitat work as you'd get more expansion from the lighter weights.

Easy to use windsurfing board repair foam. This is perfect if you get a soft deck or have to repair a large gouge in your board.