Masterseal 590 is a one-component, quick-setting, portland-cement-based hydraulic repair mortar that instantly stops running water through holes or cracks in concrete or masonry. It expands as it sets to lock into place even under constant water pressure.Applications • non-moving (static) cracks and holes with running water or moisture seepage • for immersion service • for anchoring vertical bolts • basements • foundations • retaining walls • sewers