With more and more stringent environmental regulations, is acid etching still a viable way to prepare concrete slabs before applying a coating?
According to Robert Cain of KRC Associates, acid etching is an effective and safe procedure. You must first remove curing compounds, sealers, and any oil or grease. Then spray a 10% solution of muriatic acid uniformly over the surface. Foaming and bubbling occur and the acid is neutralized as it attacks the surface. Flush the surface with water. Because the acid is neutralized by alkalies in the concrete, the flushing water can be safely washed down a floor drain. After etching, the floor surface should feel like coarse to medium sandpaper.