For years, many concrete floors were prepared for coatings by acid etching. Often, acid etch techniques are inadequate, misunderstood and result in early coating failures.
Acid etching was commonly specified as preparation for thin film coatings up to 250 microns. Following a correct procedure is vital to achieve a surface preparation necessary for proper coating adhesion.
The process to achieve the correct result is labour intensive and time consuming and thus subject to contractor abuse by cutting corners. (Once the coating is applied who can tell what the preparation was like!)
The bond or link with the concrete is just as important for ‘cheap’ floor coatings as ‘hi-tech’ floor coatings.
The disruption for the client, the hassle and expense for the contractor and the embarrassment for the paint company can be avoided with proper concrete preparation.
What is the purpose of acid-etching?
Etching is intended to remove weakly bonded cement paste from the concrete surface and slightly profile the surface by exposing fine concrete aggregate. This promotes the penetration and adhesion of thin film sealers/coatings up to 250 microns. (e.g. thin film epoxies, urethanes, acrylic and alkyd coatings).