Kaowool Rigidizer (2300ºF Colloidal Silica Hardener and Rigidizer)

Kaowool Rigidizer is a colloidal silica compound for treating surfaces of Kaowool ceramic fiber products to provide a degree of surface hardness and resistance to erosion. Kaowool Rigidizer is stabilized against freezing during exposure to cold; however, freezing should be avoided.


Standard SizesCan - 1 gallon
Drum - 55 gallon
Pail - 5 gallon
Maximum Temperature Rating ( ºC )1260
Maximum Temperature Rating ( ºF )2300
Solid ContentApprox. Silica 28 to 29%
Approx. Weight per Gallon ( kg )4.5
Approx. Weight per Gallon ( lb )10
Approx. Nominal Density, (Wet) ( lb/ft³ )75
Approx. Nominal Density, (Wet) ( kg/m³ )1202
Freezing Temperature ( ºC )-2
Freezing Temperature ( ºF )28
Viscosity, Centipoises at 25ºC4
Specific Gravity at 25ºC1.203


  • Increases surface hardness and resistance lo erosion
  • Easily applied by brushing or spraying
  • Freeze resistant


  • Surface coating for Kaowool ceramic fiber blanket exposed to high velocity gases
  • Adhesive for use in making composites and laminates
  • Surface treatment for Kaowool vacuum formed shapes to increase surface hardness

Installation Information

Kaowool Rigidizer is applied by brushing, dipping, rolling, and spraying. Suitable respiratory protection and ventilation are required when applied by spraying.

Materials to be rigidized should be free of all grease and oil. Kaowool Rigidizer receives its bonding action from the removal of physical water. Bonding may be accelerated by heating or over drying. Curing is a function of the size of the shape and its geometry.

An application rate of one gallon per 25 square feet (7.6 m²) of ceramic fiber surface will render a hard surface without completely rigidizing the interior of the ceramic fiber body.

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