• Clean all joints and remove contaminants such as grease, oil, dust, water, frost, surface dirt, old sealants or glazing compounds and protective coatings.
• The sealant is ready to use. Install backing material or joint filler, setting blocks, spacer shims and tapes.
• Mask areas adjacent to joints to ensure neat sealant lines. Primer is generally not required on non-porous surfaces, but maybe necessary for certain porous surfaces.
• It is recommended to do a test application on a small area. Apply DOWSIL 789 Silicone Weatherproofing Sealant in a continuous operation using pressure.
• The sealant can be applied using air-operated guns or bulk dispensing equipment. Before a skin is formed, (within 15-20 minutes), apply light pressure to spread the sealant against backing material and the joint surfaces.
• Remove masking tapes.

DOWSIL™ 789™ Silicone Weatherproofing Sealant is not approved for use as a structural sealant. It should not be used:

• In below-grade applications
• When surface temperatures exceed 50°C (122°F)
• On surfaces that are continuously immersed in water
• On building materials that bleed oils, plasticizers or solvents, green or partially vulcanized rubber gaskets or tapes
• On frost-laden or wet surfaces
• In totally confined joints (the sealant requires atmospheric moisture for cure)
• If the sealant is intended to be painted (paints do not typically adhere to most silicone sealants)
• To surfaces in direct contact with food or other food-grade applications
• This product is neither tested nor represented as suitable for medical or pharmaceutical uses.