Product Data Sheet

DOWSIL™ 791 Silicone Weatherproofing Sealant is a premium one-component, neutral-cure silicone sealant engineered for long-term weathersealing performance in commercial construction and façade applications. Designed for general glazing and weatherproofing joints, this architectural-grade sealant forms durable, flexible silicone rubber seals that withstand harsh environmental exposure and continuous building movement.

Its medium-modulus formulation provides exceptional joint movement capability of up to ±50%, allowing the sealant to accommodate expansion, contraction, vibration, and thermal cycling without cracking or losing adhesion. DOWSIL™ 791 offers excellent primerless adhesion to many common construction materials including glass, aluminum, galvanized steel, masonry, concrete, painted surfaces, and other porous and non-porous substrates.

This weatherproofing sealant is specifically designed for curtainwall systems, perimeter joints, expansion joints, and building façade applications where long-term durability and weather resistance are critical. Once cured, the silicone remains highly resistant to UV exposure, ozone, rain, snow, humidity, and extreme temperatures, helping maintain watertight performance and flexibility for years of exterior service.

DOWSIL™ 791 features excellent gunnability and low-string application characteristics for clean, efficient installation in both shop and field conditions. Its non-sag consistency allows for easy vertical and horizontal joint application, while the neutral-cure chemistry minimizes substrate corrosion and improves compatibility with sensitive construction materials.

Common applications include:

• Curtainwall weathersealing
• Expansion and control joints
• Perimeter window and door sealing
• Glass and metal façade systems
• Precast concrete panel joints
• General glazing applications
• Building envelope weatherproofing