PureCast 603 is a high performance, two-component liquid castable polyurethane elastomer that contains no TDI or MOCA. PureCast 603 is insensitive to typical environmental moisture and exhibits low shrinkage. PureCast 603 provides the strength and durability of a heat-cured urethane in a simple to use RTV system. It provides you with the ability to cast high strength, flexible urethane parts in urethane or silicone molds. PureCast 603 can be colored with our RV series pigments. We recommend using black or darker colors to prevent color change or applying a UV resistant coating for outdoor application. The product is reddish/brown in color. Some uses for PureCast 603 include core box liners, metal forming pads, industrial parts and abrasion resistant pads and bumpers. Purecast 603 may also be used as an abrasive resistant coating for ropes.

Application and Mix Ratio


Condition the liquid components: Component A to 90˚F-100°F to reduce viscosity which greatly aids with mixing and Component B to 72°F before combining. Warmer temperature will significantly shorten the working time and colder temperatures will length time and make mixing difficult.

In a clean plastic container, mix by Weight 100 parts of Component A (clear) and 31.17 parts Component B (black or clear amber) or mix by Volume 100 parts Component A and 32.33 part Component B.

Start mixing immediately after A & B components are added to the beaker. Use a clean flat spatula taking care to scrape the sides and bottom of the container to include all of the unmixed material.

Mix for 1 minute, mixture should be evenly mixed with no "
lines" of unmixed clear or black.

Pour mixture into prepared mold. Cami 980 silicone mold release is recommended for most surfaces.

Clean up with mineral spirits.

Metallic surfaces to be bonded should be brushed blasted to achieve a 2 to 3-mill surface profile to remove all surface oxidation and traces of previously bonded polymer. After blasting, etched surface should be thoroughly degreased using clean Toluene or mineral spirits solvent wipe. Surface is now ready for priming.

To prevent further surface oxidation, prepared metallic surface should be immediately primed using Primer 460 SPX or Primer 800 and allowed to cure in a dry environment overnight for 12 hours. This should be allowed to cure for 1 hour at 72° F before applying PureCast 603 urethane elastomer (see Primer 460 SPX or Primer 800 technical data sheet for full mixing and application instructions).

Do not allow Primer 460 SPX or Primer 800 to cure longer than 6 hours before applying PureCast 603 urethane elastomer to ensure a total chemical bond in between primer and elastomer coating.

Maintain at least 72° F during the complete application process. Colder temperatures retard curing times, warmer temperatures reduce curing times.

All primed surfaces should be kept free of moisture, dust and any grease or oil, which may interfere with polymer bond.


Working Properties

Mix Ratio By Weight

100 parts A/ 31.17 part B

Mix Ratio By Volume

100 parts A/ 32.33 parts B

Viscosity @ 72°F (A Side)

35,000 CPS

Viscosity @ 72°F (B Side)

100 CPS

Viscosity @ 72°F (Mixed)

6500 CPS


Part A:



Part B:

Black or Clear Amber



Black or Clear Amber

Working Life @ 72°F

18-30 minutes

Demold Time* @72°F

6-8 hours

Demold Time* @150°F

2-4 hours

Complete Cure Time* @ 72°F

7 days

* 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

8.59 lbs.

Weight/Gallon Part B

8.28 lbs.

Weight/Gallon Mixed

8.52 lbs.

Hardness @ 72° F

ASTM 2240-85

82-92 Shore A

Tear Strength

ASTM D-624 die C

956 lb./in.

Tensile Strength

ASTM D-412 die C

5039 psi


ASTM D-412 die C


Dielectric Strength

ASTM D-149

1,165 V/mil

Dielectric Constant

ASTM D-150

55.45 @1MHz


Clean Up

Clean up with Mineral Spirits.

Dispose of all empty PureCast 603 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 the solvents to evaporate. The containers will then contain non-hazardous cured urethane.

Storage and Shelf Life

PureCast 603 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 be between 70°-80°F and should not exceed 90°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