DOWSIL 791 Silicone Weatherproofing Sealant is a neutral-cure, one-part silicone designed for high-performance weather sealing in modern building envelopes. Formulated for curtain walls, window perimeters, and facade joints, it offers excellent movement capability, long-term flexibility, and outstanding adhesion to a wide range of porous and non-porous construction substrates. Once applied, it cures by reacting with atmospheric moisture into a durable, elastomeric silicone rubber that withstands severe weather, UV exposure, temperature swings, and long-term environmental stress without hardening, cracking, or shrinking.
Engineered for expansion, perimeter, connection, and other dynamic joints, DOWSIL 791 provides ±50% movement capability, making it highly effective in dynamic facade systems. Its neutral cure chemistry is compatible with coated glass, galvanized metals, aluminum, masonry, and many architectural finishes without staining or corrosion concerns. With excellent rheology for smooth gunning, minimal stringing, and easy tooling, installers can achieve consistently clean bead lines and reliable joint sealing performance.
DOWSIL 791 meets ASTM C920 Type S, Grade NS, Class 50 standards and is available in multiple standard and custom colors to blend with architectural substrates. It is intended for above-grade exterior applications and long-term weatherproofing where durability and joint performance are critical.




