This post was most recently updated on January 30th, 2023
Acid Etch a Concrete Surface Update
Important Note: Always take precautions when you plan on Acid Etching your concrete floor! Improper use could cause damage to both the surface and your body.
When etching a concrete garage or floor it is best to not use aggressive acids like Hydrochloric or Muriatic but a milder concentrated acid solution that produces a light etch. These concentrated solutions use a mild acid typically (Phosphoric) to lightly etch the surface for your new Epoxy Coating. Using a milder acid instead of muriatic acid gently increases the porosity of the surface without damaging the substrate thereby allowing better adhesion of the Epoxy Coating.
Using a Milder Acid For Etching Advantages:
- Less chance of damage to skin, body, and concrete surface
- Easier to use
- Better penetration/adhesion for your new coating
How to Acid Etch Garage Floor for Epoxy
- Acid Proof Pump Sprayer
- Nylon Scrub Brush
- Protective Gloves Rubber
- Protective Eyewear
- Protective Shoes, typically rubber
- 5- Gallon Pail for Mixing
- A Pressure Washer or High-Pressure Rinsing Tip on Hose
Prepping the Surface
Remove all items from the garage floor. Use a household broom to thoroughly sweep the entire garage floor. All dirt particles and debris should be swept off the floor.
Previously coated surfaces: Acid Etch Solutions will not work on previously sealed, painted, or coated surfaces. If your garage has been previously sealed, painted, or coated, the use of a diamond grinder or shot blaster is recommended to remove those coatings and rough up the surface.
Oil or Grease Stained Floors: If your concrete oil/grease on the floor, use a cleaner/degreaser a few times and then follow the etching directions.
Mixing Acid Etch Instructions
The concentrated acid solution must be diluted with water prior to use. Mix 1 part cleaning solution to 4 parts water. Surfaces with very low porosity may require a more concentrated dilution (1 part to 2 parts water).
Application of Acid Etch
Dampen the surface with clean water. Apply the material with an acid-proof pump sprayer and scrub with a nylon brush. Do not allow to dry on the substrate. Once cleaning is complete, pressure wash or scrub the surface with a neutralizer such a cleaner/degreaser or baking soda (1 Cup to 1-gallon water) and rinse with clean water, rinsing away all cleaning solution. Let the substrate dry completely before proceeding with the application of a coating or stain.
Do not mix with other products. Use protective gloves and safety glasses when handling. Avoid contact with eyes and prolonged contact with skin. Do not take internally.
Clean tools with water
Prepping your concrete floor with an Acid Etch Solution is easy to do and does not require a lot of skill or experience but it’s very important to follow the proper steps so there is not any damage to your concrete or your body. Take precautions, follow the proper steps, and your new Epoxy Coating will last for many years!
Tips Acid Etch a Concrete Surface
Have any questions on using an Acid Etch to Prep your Epoxy? If so, please ask below.
As an article and comment contributor to the site, Scott has been around the pressure washing industry since attending college. In 1993 he started his first company called Oakland Pressure Wash specializing in exterior pressure washing, concrete sealing, and deck staining. That company evolved into OPW L.L.C. shortly thereafter concentrating more on exterior restoration. Scott and his restoration Michigan company have restored over 10,000 projects in the Metro Detroit area since the early years. He has become an authority in the restoration industry and has contributed to numerous restoration forums and informative sites.
All the products he suggests through this site are sold through online sites and in retail stores, allowing the consumer to choose their own means of purchase. Scott’s eCommerce sites do sell many top brands he endorses and if you appreciate any of the help he has offered then feel free to purchase from one of them.
If etching a basement floor with no floor drain, what is the best way to rinse/ clean up the acid solution once etching is complete?
Use this: https://www.restore-a-garage.com/restore-a-garage-prep/masonrysaver-no-rinse-concrete-etch/flypage.tpl.html
The acid etch has to be rinsed off over oxide coloured concrete. Might it damage the oxide coloured concrete?
Yes, it is possible so prewet and rinse fast to avoid etching the colored concrete.
Do I need to etch a new clean concrete garage floor
If using an epoxy coating, then yes.