Summary of Acid-Etched Concrete
- Is it better to acid etch or grind concrete?
- How long does it take for concrete acid etch to dry?
- What is the best product to etch concrete?
- Is muriatic acid good for etching concrete?
Search Results
AI Overview
AI Overview
View all
Acid etching uses muriatic (hydrochloric) or phosphoric acid to clean and slightly roughen concrete for better coating adhesion, typically involving diluting the acid (e.g., 1 part acid to 3 parts water, adding acid to water), applying it until foaming stops, scrubbing, and then thoroughly rinsing and neutralizing to create a profile like 100-grit sandpaper, though modern practices often favor safer, more effective mechanical grinding.
This video shows the process of acid etching concrete:
54s
Joe Quick
YouTube • Dec 3, 2013
What it does
Removes the weak, powdery top layer (calcium sulfate) from new concrete.
Opens concrete pores and profiles the surface for better coating bond.
Creates a texture similar to 100-grit sandpaper.
How to acid etch (General Steps)
Prepare & Protect: Clear the area, sweep, and wear full PPE (gloves, goggles, respirator).
Mix Solution: Dilute muriatic acid with water (e.g., 1:3 ratio), always adding acid to water to prevent splashing.
Apply: Lightly wet the concrete, then apply the acid solution evenly.
React: Let it foam (usually 2-10 mins); foaming indicates it’s working. Reapply to missed spots.
Rinse & Neutralize: Thoroughly rinse with water and a power washer, potentially multiple times, to remove all acid and residue. Some sources recommend neutralizing with a base like sodium hydroxide (NaOH) and rinsing again.
Dry: Allow the concrete to dry completely (days) before coating.
Important Considerations
Safety: Muriatic acid is caustic; it damages skin, clothes, and metal.
Residue: Incomplete rinsing leaves residue that causes coating failure.
Modern Alternatives: Grinding is often preferred for better, more consistent results, though it’s more complex.
Wait Time: For new concrete, wait until the initial “calcium push” subsides (around 28 days) before etching.
This video explains the differences between acid etching and grinding:
58s
Epoxy Flooring Co
YouTube • Feb 17, 2021
Acid Etching Is No Longer Recommended as a Concrete Prep …
Acid etching is the process of applying hydrochloric/muriatic or buffered phosphoric acid to a slab, then rinsing it off with wate…
Sherwin-Williams Industrial Coatings
Acid Etching/Washing Concrete Versus Grinding
Acid washing a concrete floor is a method used in preparation for applying an epoxy coating. It involves applying an acidic soluti…
YouTube
Concrete Etching – A Complete Guide to Etch Concrete Surfaces
Acid etching vs. grinding is a common comparison when deciding the best way to prepare concrete for sealing. Acid etching with mur…
Dustless Blasting
Show all
Show more
Acid-Etched Concrete
Acid etching prepares concrete to bond with paint, an epoxy or a stain
Acid etching is the process of roughing up the slick surface of concrete with chemicals. Concrete can also be roughened with a grinder, but acid will do it with much less dust and muscle power. Acid creates tiny holes in the surface of the concrete, allowing it to bond with topical treatments such as paint, epoxy or stain.
Typically muratic acid is used to chemically treat concrete so that it can form the proper bond with topical surfaces. This concrete had metal flakes sprinkled on while the concrete was wet, then the surface was acid etched.
Acid combined with stain will etch and color the concrete at the same time. Applying stain can be tricky, and puddles and thin areas should be avoided to prevent the look from being mottled.
The longer the acid is left on the surface, the more porous the concrete becomes. Note the grainy pits in the surface of this kitchen floor. After etching, a neutralizer needs to be applied to stop the chemical reaction. Some acids time out so that neutralizer isn’t necessary.
Even with a careful application of an acid or stain chemical, a natural amount of imperfection will result. A marble-like effect is created, because the acid is unpredictable. The result is a wonderfully unique surface.
Concrete also needs to be acid etched before you can apply epoxy. Epoxy is a polymer-based adhesive or paint that has a plastic feel to it. Thicker than paint, it has the benefits of being stronger as well as oil and heat resistant, and it fills in surface imperfections easier. Epoxy floors are common in professional garages.
The industrial look of this floor was created with an acid stain and the stubborn leftover adhesive from the original flooring. At times the best situations arise from accidents.
Acid stain comes in a variety of colors. Color can also be added by sprinkling pigment on the wet surface after the concrete is poured.
Whether the acid etching happens before the stain, epoxy or paint is added or not, the amount of sheen or gloss is determined by the clear topcoat. A high-gloss topcoat reflects light but also creates the most slippery surface.
This concrete floor was acid etched and then painted with a low-sheen paint, creating a matte look, and a topcoat was not used.