IsoCast RCR 739

IsoCast RCR 739 (Formerly PAK Mark 15) is used to make castings from rigid and flexible molds. Some of the most common uses of IsoCast RCR 739 are point-of-purchase displays, rapid prototypes, special effects, taxidermy, and sculpture reproductions. However IsoCast RCR 739 can be used for any application that requires a lightweight, durable plastic.
IsoCast RCR 739 is a two-part, MDI-based polyurethane casting system. It is mixed one-to-one by volume and cures at room temperature. IsoCast RCR 739 begins to gel in about 15 minutes and cures to a white color.



  • Convenient mixing ratio (s)
  • Fast hardness development
  • Low shrinkage
Product Types

Casting Resin


Product Testing

Test PerformedTest Results
Color - ISOAmber  
Color - POLWhite  
Compound Specific Gravity1.09  
Compressive Strength - ASTM D69510,200 psi 
Compressive Yield Strength - ASTM D69510,200 psi 
Demold Time0.5-1 Hour 
Elongation - ASTM D41210 % 
Full Cure7 Days 
Hardness - ASTM D2240 - Shore D76-80 Shore D 
Izod Impact Notched - ASTM 256A0.11 
Izod Impact Unnotched - ASTM 256E13.4 
Izod Impact-Notched, Four Specimens - ASTM D256-93A0.21 
Linear Shrinkage - ASTM D25660.001 in/in 
Mix Time - by Hand1 Minutes 
Modulus of Elasticity - ASTM D7901897 psi 
Pot Life - 100g12-15 Minutes 
Ratio by Volume - ISO:POL1-1  
Ratio by Weight - ISO:POL1.09-1  
Rebound, Bayshore % - ASTM D263220 % 
Shrinkage0.001 % 
Split Tear - ASTM D470115 pli 
Stress - ASTM D790 - at 5% Strain68.2 psi 
Tear Strength - ASTM D624, Die C820 pli 
Tensile Strength - ASTM D4128000 psi 

Posted on

May 18, 2020