Vinyl Foam: Divinycell 4 lb. DensityDIAB closed cell vinyl foams are valued for their superior structural and mechanical properties. When used as a structural sandwich core, these foams combine ultra low weight, improved stiffness, and impact resistance. In particular, our 4 lb. cubic foot foam is employed extensively in marine (leisure, military and commercial) and automotive applications. Extremely easy to handle, including cutting, shaping, and thermoforming with a heat gun or oven