Rust-Oleum 265985 Zinsser® Watertite® Concrete Etch & Cleaner

Clean and prepare concrete, stone, brick, tile and galvanized metal. Quickly restores a stain-free surface and also preps it for painting, patching, or waterproofing. Removes efflorescence. Safer than muriatic acid. Use a wire brush to scrape off loose mortar or dirt before applying