Which is the least expensive way to add color to concrete – acid or staining or dying?
Muratic acid to etch is very deleterious to a concrete. The hydrochloric content dissolves the lime in the matrix [that’s what makes the bubbles] causing a de-bond of aggregates and fines from the mix [thats why there is a residue of sand]. In addition to eroding the surface, it reduces the concrete pH and opens up the pore structure causing more problems than you can imagine. “Weatherability” is a minor concern! Any steel in concrete looses the passivating layer and begins to rust when the pH level surrounding it drops below 11.5, so whatever you do, keep the pH high or a least neutral on a surface.
