KWIK-Key is a milky-white, general-purpose latex primer designed to improve adhesion, strength, flexibility, and water resistance across all cementitious and gypsum-based substrates. It enhances the bonding of tile adhesives, mortars, screeds, and renders — especially on smooth, dense, dusty, or highly absorbent surfaces. It is also used to create a high-performance slurry coat for non-porous substrates, tile-on-tile applications, and painted or sealed surfaces.