Chalk-Bond + Clear 100% Acrylic Primer-Sealer Concentrate is a water reducible acrylic emulsion primer sealer specifically designed to bind oxidized paint residue - (chalk), as well as other forms of small particles of foreign debris to the substrate. Easy to apply, it provides excellent adhesion and its special formulation penetrates and seals bare masonry surfaces allowing specified paint coatings to be applied more smoothly. Concentrated - 1 gallon makes 4 gallons mixed!