Is Muriatic Acid or Etching Product Best to Prepare Concrete Floors for Coating?

Question:

I plan to use one of your professional quality floor coatings. Is it better to use muriatic acid to etch and prepare my concrete floor, or just use one of the etching products from my home supply store?

Answer:

The best solution is actually to do mechanical abrading (grind).  Your can rent a floor sander or grinder from many rental companies, and there won’t be the need to wait as long for the surface to dry after. Aside from that, muriatic acid is a stronger etcher than most of the “all in one” products. The upside of such other products like this one: https://www.lowes.com/pd/Valspar-Fast-Prep-Interior-Exterior-Concrete-Cleaner-and-etcher-Actual-Net-Contents-128-0-fl-oz/1000380861 is that they claim to both degrease and etch. You will need to check the surface after either type of etching to ensure it feels like fine sandpaper. It shouldn’t be slick if you want the coatings to last.

Additional note.. Muriatic acid won’t etch if there’s layer of oil or other contaminants. Spread some water over surface first, and see if it beads up anywhere. Those areas need a degreaser/cleaner first. If trying the multi-purpose products, let it dry and double check to see if it still beads. Some of these products are not concentrated enough to do the job in one application.