For preparation of concrete surfaces, Ni-Build Filler Compound No. 209HB is a strong-bonding epoxy material that was engineered to fill large voids and open joints in concrete substrates prior to the application of a protective topcoat. It is formulated to be lightweight, which allows for the thicker application. The product is easy to apply and creates a smooth finish and appropriate bonding surface for the preparation and application of a protective coating or lining. The physical properties include compressive strength exceeding 5000 psi. It has a curing time of 30 minutes at 70º Fahrenheit and a recoat window of 24 hours, enabling fast track scheduling. Sauereisen . 412-963-0303.