TrueCast 70-Slow is a versatile, two component liquid castable polyurethane elastomer. TrueCast 70-Slow combines high strength and durability with easy processing at room temperature. TrueCast 70-Slow can be used for casting urethane parts or flexible molds.

Application and Mix Ratio

Component A and component B are supplied in 1 and 5 gallon plastic containers. Component B should be thoroughly mixed before using. Component A does not need mixing. Carefully weigh out One-Hundred (100) parts of Component A to Fifty (50) parts Component B. Mix together for 1 to 2 minutes by hand using a spatula for small batches (1/2 gallon or less), or electric drill and jiffy mixer for larger batches. Use silicone mold release. TrueCast 70-Slow is fully cured in 24 hours at 72°F. Colder curing temperatures will lengthen cure times. Warmer temperatures will greatly reduce working and cure times. Curing can be heat accelerated (150°F/ 8 hours) to speed up processing. Use methyl ethyl ketone (MEK), acetone or mineral spirits for clean-up.


Working Properties

Mix Ratio By Weight

100 parts A/ 50 part B

Mix Ratio By Volume

100 parts A/ 49.63 parts B

Viscosity @ 72°F (A Side)

2500 CPS

Viscosity @ 72°F (B Side)

2000 CPS

Viscosity @ 72°F (Mixed)

2200 CPS


Part A:



Part B:

Medium Blue



Medium Blue

Working Life @ 72°F

8-14 minutes

Full Cure Time* @ 72°F

72 hours

* Set time and Demold time depends on temperature and relative humidity.


Physical Properties

Specific Gravity (Part A)


Specific Gravity (Part B)


Specific Gravity (Mixed)


Weight/Gallon Part A

8.57 lbs.

Weight/Gallon Part B

8.64 lbs.

Weight/Gallon Mixed

8.60 lbs.

Cubic inch per lb. of product


Hardness @ 72° F

ASTM 2240-85

65-75 Shore A

Tear Strength

ASTM D-624

175 lb./in.

Tensile Strength

ASTM D-412 die C

2300 psi


ASTM D-412 die C


Shrinkage, inches

ASTM D-2566



Clean Up

Dispose of all empty TrueCast 70-Slow component containers in accordance with local, state and federal regulations. Empty component containers can be rendered non-hazardous by rinsing the containers with a small amount of mixed material and allowing material to cure for 24 hours. The containers will then contain non-hazardous cured urethane.

Storage and Shelf Life

TrueCast 70-Slow is shipped from the factory in sealed containers. The containers should be stored in a cool, dry area that is protected from direct sunlight and moisture. Storage temperatures should not exceed 80°F. The shelf life of the factory sealed containers stored under these conditions is six months. Containers that have been opened should be resealed immediately after material has been removed in order to prevent solvent evaporation.


Shipping Class: Class 55 Non-hazardous