A one-part, film-forming primer for use with most DOWSIL™ sealants on porous and cementitious surfaces to promote adhesion. Also suitable for metal substrates, such as polyvinylidene fluoride (PVDF) coating resin painted aluminum, when properly prepared. It is an air drying primer supplied as a solution of reactive materials in solvent. Should not be used with DOWSIL™ 790 Silicone Building Sealant, DOWSIL™ Contractors Concrete Sealant or DOWSIL™ Parking Structure Sealants.