Polyurethane solvent-free primer for absorbent substrate to promote adhesion of MAPEFLEX one-component polyurethane sealants on all types of porous absorbent building substrates such as concrete, mortar, wood and brick. TECHNICAL DATA: Consumption: 5-10 g/m of 1 cm deep joint treated with primer. Packaging: 250 g and 2 kg canisters.