Mix these two-part foam casting compounds and pour into your mold—they expand to fill every hole and cavity. Because they're foam, they're lighter weight than other casting compounds.

The foam's expansion is related to its density. Denser foam expands less; lighter foam expands more.

Flexible compounds cure into soft foam; use them to cast gaskets, cushions, and other bendable objects. The foam is open cell, which means it will absorb water, air, and gases.

Rigid compounds form stiff, closed-cell foam, which prevents water and air from flowing through the part.

Machinable compounds are dense enough to create prototype modeling blocks, so you can make mockups and test out tooling setups with little cost and less wear on your tools.

Compounds that meet FMVSS 302 prevent the spread of flames. Originally used for seat cushions and arm rests in cars, these compounds conform to U.S. Federal Motor Vehicle Safety Standards for flammability of interior materials.

UL 94HB-rated compounds have been tested to ensure that flames extinguish or do not spread quickly.

Before casting, apply a mold-release lubricant to prevent the part from sticking, stretching, and tearing. These wax-based lubricants won't cause the foam to collapse as it cures. Because they leave a residue, parts should be cleaned before painting or coating.