Polyurethane Foam and Resin

Three Pound Density

Polyurethane foam, 3 lb density. Also known as A-B foam. Mix two equal parts of Part A and Part B and compound will expand about 20 times to form a rigid mass of foam. Not the same as the spray foam you get at the hardware store. Doesn't form a consistent skin. Stronger than the 2 pound stuff. Great for making foam armatures on which to sculpt. Water blown. A 12" x 12" x 12" block of this stuff will weigh about three pounds. A kit consists of two equal volumes of material. For example, a quart kit will contain one quart of part A and one quart of part B. Doesn't expand as much as the two pound kits so the material won't go as far.

  Rigid Foam MSDS Sheet

Odorless Casting Resin or Plastic Casting Resin. Not completely odorless but is called that anyway. Mix two equal parts of Part A and Part B and compound will form a solid plastic in a few minutes. Great for artists who want to reproduce their own "Resin Kits." Works great in a silicone mold. Color is sort of a amberish, translucent white. Can be painted, but don't use a silicone mold release.

Basically if you take a block of foam that is 12 inches by 12 inches by 12 includes and set it on a scale the foam will weight the density specified. Three pound foam would weigh three pounds, the two pound foam would weigh two pounds, etc..

For rigid foams the basic gallons kit weighs about 17 lbs.

Therefore the yields for the rigid foam kits are:

RF3-16x2 = .7 cubic feet
RF3-32x2 = 1.4 cubic feet
RF3-128x2= 5.6 cubic feet

Soft foam is a different matter. The kits are not equal amounts. Usually the part B is about 60% of the mix and part A is 40% of the mix. When we specify a gallon kit it means the side B will be a full gallon and the side A will be what is required for its 40%. Usually the density is about 3.25 lbs. per cubic foot.

These are rough calculations based on perfect conditions. Expansion rates are affected by product temperature, mold temperature, humidity and accuracy of the mix.