MasterSil Primer 718 is a silicone primer formulated for MasterSil RTV systems, including one- and two-part silicones and sealants. It promotes adhesion to difficult-to-bond substrates such as metals, rubbers, and plastics like ABS, polycarbonate, polyphenylene oxide, polysulfone, polyester, styrenics, and rigid PVC. Most importantly, it can also be used with silicone rubber substrates.
It is a low viscosity, colorless liquid which can be applied by brushing, wiping or dipping. A uniform coating is applied in a thin layer. Using a primer coating on styrene and polycarbonate surfaces is recommended to avoid crazing or surface stickiness. A minimum drying time of 20 minutes at ambient temperature is recommended before applying the RTV silicone adhesive/sealant. The primer may be allowed to dry for up to 24 hours before applying the RTV compound without any loss in bonding performance. However, the primed surface must be covered to prevent dirt or contaminant pickup. MasterSil Primer 718 has a shelf life of 6 months when stored in its original unopened container at 25°C (75°F).
