Expanding urethane pour foam is a two-part, closed-cell liquid foam system that expands rapidly when mixed. It's used for flotation, insulation, soundproofing, and filling voids in boat hulls, decks, and other marine structures.

No. This foam is designed specifically for pour into place applications.

Foam expansion is temperature-sensitive. For best results, both the foam and the working environment should be around 80°F. At 50°F, expansion can be reduced by 50% or more. Warm the product before use if needed.

Use 2 lb foam for standard flotation applications. It offers about 60 lbs of buoyancy per cubic foot. For added strength or to support a deck, 4 lb foam is a better option.

Once Parts A and B are mixed, you’ll have roughly 45 seconds before expansion begins. Stir vigorously for about 25 seconds, then pour immediately. The foam expands fully in about 5 minutes and hardens in 15 minutes.

Yes. You can pour in multiple layers, waiting 15–20 minutes between pours. This method helps control expansion and ensures complete curing without overheating.

Measure the volume of the space in cubic feet (length × width × height). Each cubic foot requires about 2 quarts of liquid foam (combined Part A and B).

Yes. Once cured, urethane foam is resistant to gasoline, acetone, and most solvents. It cannot be dissolved—only mechanically removed by sanding or scraping.

Yes, you can pour foam into molds. For easy release, use a mold release wax like Partall #2 or line the mold with smooth plastic sheeting. Porous molds should be sealed before applying wax.

Yes, but with caution. You’ll need to calculate the internal volume of the space and ensure it’s dry and sealed. For pipes or long, narrow cavities, be aware that foam only flows a few feet before expanding. For anything over 5 feet in length or under 2" diameter, results may vary—test beforehand. Read the full post on how to fill your pontoons with foam