TotalBoat Liquid Urethane Foam Kit 2 Lb Density, Closed Cell for Flotation & Insulation (2 Gallon Kit) Marine-grade, 2-part liquid polyurethane expanding flotation foam with simple 1:1 mix ratio by volume. Sets up quickly, and cures at room temperature. Lightweight, 2 lb. density is ideal for adding buoyancy, insulating, soundproofing, and filling gaps or voids. For nonstructural applications only. Shelf life is 6 months from date of manufacture. Cures to a rigid, 94% closed-cell foam that resists water absorption, and is not affected by gas, oil, or solvents. Once fully cured, foam can be coated with polyester, epoxy, or vinyl ester resins, without melting. It can also be cut to desired shape easily. Cures to a rigid, 94% closed-cell foam that resists water absorption, and is not affected by gas, oil, or solvents. Once fully cured, foam can be coated with polyester, epoxy, or vinyl ester resins, without melting. It can also be cut to desired shape easily. Pourable polyurethane foam is very easy to use, expands rapidly, and hardens in place in about 5 minutes at 70-80F, with minimal shrinkage. Foam can be poured in separate batches to build up multiple layers, forming strong bonds between layers. Sizes: Available in 2-Quart and 2-Gallon Kit sizes; Yield: 2-Quart Kit  2 cubic ft., 2-Gallon Kit  8 cubic ft.; Flotation Range (admixed): 75 lbs./qt. and 300 lbs./gal.; PROPER TEMPERATURE, TIMING, MIXING, and VENTING ARE CRITICAL TO ACHIEVING PROPER EXPANSION - Application Temperature: 75-80F; Mixing Time: 25 seconds (mix thoroughly; there should be no visible swirls in the material); Pouring Time Before Foaming Starts: 45 seconds; Full Expansion: Approximately 7 minutes.