3350 W. 48^th Pl. Chicago, IL 60632-3000. Phone 773-927-3484, FAX 773-650-5853.

Source for liquid thermosets: silicones, moldmaking urethanes, casting plastics, polyester resins, epoxy.
Fiberglass fabrics, release agents, fillers and dyes.
All products available in small quantity.

This series of two-component urethane moldmaking rubbers has been used in the casting of cement, plaster, gypsum and concrete. There are three versions stocked at Eager Plastics:

PMC121-30 WET
PMC121-40 DRY
PMC121-50 WET

All three systems have the same convenient "one-to-one" (by volume) mix ratio that allows for quick measuring and easy pouring of the mold rubber, so there is no need for a scale. The working time is 20 minutes and full cure is 16 hours.

There are two main differences in the above products. The number after the 121- indicates how flexible the cured system is, rated as Shore 'A' hardness. Thus the #30 is the softest (30A hardness) and the #50 is the stiffest (50A hardness). The second main difference is whether the system is wet or dry. The WET system has a release agent already dissolved in the liquid components. When the system cures, the surface of the mold is lubricated for easy casting of cement, plaster, gypsum, concrete or urethane plastics without need for a release agent. The DRY system has no lubricant added to the mix, so casting of plastic parts requires the use of a release agent. The dry system has been used extensively for CASTING FLEXIBLE PARTS.

The PMC-121 series (30, 40 or 50) is available from Eager Plastics in the following sizes:

2 Pint Kit
2 Gallon Kit
10 Gallon Kit
110 Gallon Kit