Smooth-On Oomoo 25 - Molding Silicone

OOMOO® 25 is an easy to use silicone rubber compound that features a convenient one-to-one by volume mix ratio (no scale necessary). It has low viscosity for easy mixing and pouring. Vacuum degassing is not necessary. This product cures at room temperature with negligible shrinkage. OOMOO® 25 has a 15 minute pot life, with a 75 minute cure time.

OOMOO™ 25 is suitable for a variety of art-related and industrial applications including making one and two-piece block molds for sculpture and prototype reproduction, casting plaster, resins and wax. OOMOO™ silicones are also suitable for electrical potting and encapsulation applications.


  • Convenient one-to-one by volume mix ratio (no scale necessary)
  • Low viscosity for easy mixing and pouring . . . vacuum degassing is not necessary

Data At-A-Glance

Mix Ratio By Volume 1A:1B
Mix Ratio By Weight 100A:130B
Specific Gravity 1.34 g/cc
Specific Volume 20.6 cu. in./lb.
Pot Life 15 minutes
Cure Time 75 minutes
Color Light Blue
Shore Hardness 25 A
Tensile Strength 240 psi
Elongation @ Break 250 %
Shrinkage 0.0025 in. / in.
Die B Tear Strength 40 pli
Useful Temperature (min) -65 °F
Useful Temperature (max) 400 °F
100% Modulus 100 psi
Mixed Viscosity 4,250 cps

Next Previous

Related Items