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)

Meet expectations.

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

Replaced foam under floorboards in my boat and this product worked extremely well.

This is good stuff, not soft, squishy foam. Very high density and tough

Good stuff, There's definitely a learning curve, but that's on me. Using between thin fiberglass sheets (Boston Whaler resto) I appreciate it's ability to maintain some density even when allowed to expand freely, without deforming the skin.