Step 4 · Etch or Grind the Concrete

The concrete surface needs to be porous to ensure the epoxy adheres properly. This can be achieved in two ways: acid etching or mechanical grinding. For acid etching, mix a concrete etching solution (typically phosphoric or citric acid-based) with water according to instructions, spread it over the floor, scrub, and then rinse thoroughly, neutralizing any remaining acid. For mechanical grinding, use a concrete grinder with the appropriate diamond tooling to create a consistent profile across the entire surface. After grinding, vacuum all dust thoroughly.