Lucas #8500 Silicone Mastic is a high solids non-shrinking moisture cure silicone mastic intended for flashing, sealing and repairing roofs, walls, masonry and metal roof seams & fasteners. #8500 has minimal odor, contains no solvents and less than 10 grams per liter VOC. Use to seal penetrations and terminations prior to application of Lucas #8000 100% Silicone Roof Coating. Excellent adhesion to concrete, masonry, vinyl, fiber cement, polyurethane foam, EPDM, aged acrylic coatings, granular cap sheet, wood, metals, Kynar and most other common building materials. May be applied to wet and underwater surfaces. Lucas #8015 TPO Primer is required for application TPO roofs.

Lucas #8500 is a non-reactive oxime, neutral cure silicone and will bond extremely well to a wide variety of surfaces. It does not emit acidic byproducts during cure like acetoxy silicone sealants.

Application:

Surface to be sealed must be clean but may be slightly damp. Apply with a trowel or 4 inch chip brush at a minimum of inch thick and taper the edges of the application. Lucas #8500 is immediately weather resistant.

Application below 32F (0 C) is possible however curing requires free moisture in the air and will not begin until the temperature is above freezing.