Primer 200™ is a single component urethane adhesion promoter for concrete and masonry surfaces. Simply brush or spray Primer 200™ onto concrete surface and wait 1 hour. Primer 200™ is used to bond UraSeal 210™ to cracks and expansion joints in concrete surfaces. Primer 350™ is a two component self etching primer used to increase adhesion of urethanes to aluminum, galvanized, copper, bronze and steel surfaces. It may be applied by spraying, brushing or dipping surface. Primer 350™ must be coated with Primer 450™ adhesion promoter before application of urethane coating. Primer 450™ is a two component urethane primer used to increase adhesion of urethanes to painted metal surfaces, wood, plastic and concrete. It is also used as a bonding agent between new and old urethane surfaces. Primer 450™ is required for the application of new coatings over an existing urethane surface. It may be applied by spraying, brushing or dipping surface. For best results, surface should be cleaned, abraded and wiped with solvent prior to application. When recoating spray-on truck bed liners, Primer 450™ must be used to bond new coating to existing liners. Cure time depends on temperature and relative humidity.