High Performance Silicone Sealant

ASI 502 is a one-part, moisture-curing RTV (room temperature vulcanizing) silicone that cures to a strong, silicone rubber that maintains long-term durability and flexibility. Fully cured, ASI 502 has excellent adhesion to glass, metal, porcelain, ceramic, wood, most plastics and many other nonporous substrates. A technician’s preferred silicone for filling holes at customer installations.

SKU: ASI502 Categories: , Tag:


  • Mold & Mildew Resistant
  • Interior or Exterior Application
  • Resists Yellowing & UV Degradation
  • Weather Resistant, Long-Term Use


2.8 oz


ASI 502 (ASI 100% RTV Silicone) is ready to use and requires no mixing or additives. The cure mechanism begins as soon as the sealant comes in contact with the air.

At conditions of 25°C(77°F) and 50% relative humidity, the sealant will skin in 10 minutes and fully cure in 24 hours (1/8 bead) and reaches its maximum adhesion in 7 days. Higher humidity accelerates cure. Tooling, if necessary, should be done before skinning takes place.

In applications where partial or total confinement of sealant is prevalent, the time required for proper cure is generally lengthened by the degree of confinement.

Surface Preparation

All surfaces should be clean and dry. It is recommended that bonding surfaces be solvent wiped with naphthas, ketones or chlorinated solvents. Specific solvents would include xylol, toluol and mineral spirits.

In case of plastics, determine suitability of solvent prior to use. Allow surface to dry thoroughly before applying sealant. Do not solvent wipe with alcohols or oil-containing solvents such as Varsol.


Priming for ASI 502 is not normally required for applications to nonporous surfaces.

Unprimed adhesion can be easily tested by applying a small trial bead and allowing 7 days for maximum adhesion to occur. If primer is required, contact ASI.


ASI 502 sealant should not be applied to surfaces that will be painted. Painting over sealant is not recommended because the paint film does not stretch with the extension of the sealant.