FormRub 35 Liquid Rubber

Mold Rubber for Casting ConcreteFormRub 35 Liquid Rubber is the softest option (Shore A35) in the FormRub Series. This two-part, polyurethane rubber is designed to make high-performance molds that are particularly well-suited for casting and texturing concrete. Other common casting materials include plaster, wax, and, with proper release agents, some resins and foams.

The high elongation and tear strength of FormRub 35 molds make them ideal for casting veneer stone, intricate architectural elements, edge or trim strips, decorative panels and tiles, and many other cast stone products with deep relief or irregular undercuts that require a flexible, yet durable mold option.

This liquid rubber has a 1A:1B mix ratio, a very low mixed viscosity and can be demolded after ~16 hours at room temperature.

Thicken FormRub 35 with PolyFiber II for brush-on application.



Mix Ratio Shore Hardness Pour Time Cured Color Mixed Viscosity Specific Volume Demold Time
1A:1B A35 15 min. Turquoise 600 cP 27.2 in³/lb ~16 hr.
Accessories: 74/75 Part C Softener74/75 Part X AcceleratorPolyFiber II Thickening AgentUV AdditiveTietex® FabricPoly Purge Aerosol Dry Gas


Product Literature: Technical Bulletin | Safety Data Sheets | Physical Properties Bulletin | Sealers & Release Agents Selection Guide

Video Tutorials on YouTube: How to Make a Concrete Log Mold 


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