ACIDIC BONDING CONCENTRATE pH sealer 250 ml ACIDIC BONDING CONCENTRATE pH sealer 250 ml is a professional grade product designed to seal and protect surfaces from stains, dirt, and water. It is formulated to form a protective barrier on porous surfaces, such as concrete, brick, and stone. It is also suitable for use on non-porous surfaces, such as glass, ceramic, and metal. This product is designed for use in both indoor and outdoor applications and is perfect for protecting surfaces from the damaging effects of acid rain and other harsh elements.