6 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boats, Dock Flotation, Carving, Soundproofing, Filling Voids, and Insulation (1 Gallon Kit)

Works great for my taxidermy molds Expands roughly 4 times liquid amount and is rock solid ( 6lb )

I used this product to pour through a small hole into an area that an animal was attempting to dig under my deck. It expands pretty rapidly and you need to get it poured as fast as you can after mixing it. You have maybe a 60 second working time before it takes off. It expands very rapidly and voluminously. It filled the area with decently hard cured material. Just don't put it someplace fragile and confined, it will very happily push out thin wood on its way to full expansion. The end material seems acceptably durable. It builds a thin skin on itself and it's not easy to rip apart or dislodge. The resultant material also sticks aggressively to anything, so make sure you are ok with that. Also, don't get the pre-cured material on your hands; it sticks extremely well to human skin and it will be a pain to get off. Overall a great product for filling spaces!

Used this to insulate around a bathtub and it worked great. The foam expanded exactly as expected and provided a solid, supportive fill without over-expanding or creating pressure issues. Once cured, it formed a dense, durable barrier that helps with both insulation and soundproofing. Just be sure to follow the mixing directions carefully and prep your area—it sets fast. Highly recommend for home projects where a strong, stable fill is needed

Works extremely well!

Great for tub repairs.. Injecting under tub floors for support, to lift floors up a bit, prevent tub floor sagging. Also great for injecting into inner tub walls to use as a backer for the rest of your repair once it's hardened. Allows one to continue and complete the repair job in one fell swoop.