C.R. LAURENCE 9542 CRL Black 10.3 Fl. Oz. Insulating Glass Silicone Sealant. CRL Insulating Glass Silicone is a single component, acetic cure silicone glass sealant specifically designed for producing long lasting insulating glass units when used with a primary seal of polyisobutylene. It contains adhesion promoting additives for excellent glass-to-glass adhesion, and is resistant to ultraviolet light and weather extremes. It has a functional temperature range of -80 F to 400 F (-62 C to 204 C).. Part Numbers Variations: 9542