Acrylic Block Filler is a premium plus 100% acrylic heavy-duty interior/exterior block filler designed to fill pores and small voids in CMU (concrete masonry units) without shrinking or cracking. Provides excellent filling, holdout, and foundation for a wide variety of conventional topcoats including epoxy coatings. The products’ 100% acrylic composition will provide better efflorescence and alkalinity properties.