Dow. Help eliminate air infiltration and associated comfort, moisture, and pest problems with Froth-Pak Foam Sealant. The two-component quick-cure polyurethane foam fills gaps and cracks and cures in minutes, the maker says. Suitable for interior or exterior applications, Froth-Pak Foam Sealant is ideal for roof and wall junctions; wall and attic penetrations; electrical, mechanical, and plumbing penetrations; and other cracks or crevices in the building envelope. 800.232.2436.