Pecora BC-158 is a one-part gun grade caulking, sealing and glazing compound formulated from virgin butyl rubber. Because of the well-known durability of butyl rubber, Pecora BC-158 provides a long- lasting durable seal between joints of similar and dissimilar surfaces. Questions? Contact us
Provides a durable long-lasting seal between all types of masonry, steel, aluminum, glass, wood and other common construction materials.Also for sealing glass in channel glazing panels, caulking joints, mullions and flashings in curtain wall construction, and installation of insulated glass units in metal or wood frames. BC-158 is USDA approved for use in food processing plants.
Joint Design: For optimum perform- ance, joints should be designed for no more than 5% extension or compression. Neither the width or the depth of the joint should be less than 1/4” (6 mm).
Ideally, the depth should be one half the width.The maximum recommended width is 3/4” (19 mm), with a depth range of 1/4” to 3/8” (6 to 9 mm).
Surface preparation: Joints must be clean, dry and free of foreign matter, including form-release and curing agents in concrete joints or protective coatings on aluminum. Priming is not required.
Joint Backing: Joint backing materials control the depth of the sealant and permit the sealant to be installed under pressure. Joints should be filled to within 1/2” of the surface with polyethylene or polyurethane backer rod, preferably of a non-gassing, non-absorbing type. Use a size that will compress about 25% when installed.Where it is not possible to use a backer rod, use a bondbreaker tape at the bottom of the joint to prevent three-sided adhesion and allow for free movement of the sealant after it has cured.