Concrete Acid Etching
Acid etching is accomplished by use of spraying the acid solution onto the concrete causing a foaming action. Next the solution must be agitated with scrubbers and/or floor buffers followed by thorough rinsing of the surface to remove any acid and concrete residue. After rinsing the surface neutralization of ph is required. This is typically accomplished with the use of TSP or Tri-sodium Phosphate.
Acid etching is used most often for D-I-Y applications. Done properly acid etching opens the pores of the concrete creating a light texture similar to that of 100 grit sandpaper.
The negatives are typically related to the improper coating selection. Due to the mild texture of the acid etched concrete, thick products tend to have inferior bond than thin products like sealers. The second major drawback is moisture. The vast majority of coatings are moisture sensitive requiring as much as 24-48 hours of dry time prior to application. There is a common misconception that acid etching as named is dangerous and uses harmful chemicals and special safety equipment. Muriatic acid one of the old mainstays has partially contributed. Today the premium acid etches products used buffered organic acids, detergents, and emulsifiers to etch as well as clean. There use also negates any need to neutralize the acid. It is still possible to purchase muriatic acid from local hardware stores and due to cost some individuals still choose to use it. It is however discouraged by the vast majorities of manufactures and contractors.