How to Apply Translucent Acid Stain to Concrete

Translucent stained concrete

Translucent acid stains are used on a concrete surface to create a penetrative coloring to the stone. When applied to the concrete, the acid etches into the surface, creating a path for the metallic salts in the stains to react with the lime in the concrete. The water in the stain adds fuel to the reaction, which creates a color compound that changes the color of the concrete itself. This makes the acid stain permanent, and because it penetrates the concrete the colors last for years. The result is a new color over the entire surface of the concrete.

Things You'll Need

• Degreasing cleaner
• Power washer
• Acid stain
• Sprayer rated for acid use
• Baking soda
• Water
• Mop
• Push broom
• Wet vacuum
• Concrete sealant
• Foam roller

Instructions

1. Clean the surface of the concrete thoroughly. Any color variations in the concrete will show through once the stain is applied, with blemishes becoming more noticeable after application. Use a degreasing cleanser to remove stains, and then wash the surface using a power washer set to 40 or 60 degrees. Allow the surface to dry and then sweep away any residual dirt.

2. Stain an unobtrusive sample area of the concrete to determine what the final application is likely to look like. Spray the stain onto the sample area and allow it to dry. If the results are as desired, continue with the application.

3. Spray the rest of the concrete surface. Spray an even coverage of the stain over the entire surface, taking care not to pool the stain in any one place. Push a broom over the sprayed areas to scrub in the stain. Make sure every inch of concrete is covered with the stain. The color will vary according to how much stain is used. Use a light application for a dusting of color, and for deeper colors use a heavier stain application. Using the broom will leave slight marks in the stain so go over the surface a second time with the stain as a topcoat to cover the marks. Work in sections to prevent stepping onto the scrubbed-in stain when applying the top coat. Wait for a period of time specified by the stain manufacturer for the stain to react completely with the concrete.

4. Neutralize the acid in the stain with a mixture of 1 lb. of baking soda to 5 gallons of water. Saturate the floor with the mixture, applying with a mop. Wet down the floor heavily to both neutralize the acid and remove the stain residue. Remove the neutralizer from the area using a broom to push it away, and then use a wet vacuum to remove any remaining water. Repeat the removal process to completely remove the acid. Allow the floor to dry overnight.

5. Apply a concrete sealer to the concrete. Roll the sealant onto the concrete using a foam roller. The sealant will protect the color from wear and make the concrete easier to maintain. Allow the sealant to dry completely before use.

Tips & Warnings

• Etch concrete only after it's completely cured.

• Avoid walking on unneutralized areas of the floor to prevent moisture on your shoes from activating the dried acid stain.

References

• Concrete Ideas: Concrete Staining
• Concrete Ideas: How to Acid Stain Concrete
• Graniterock Theater: Acid Stain

Resources

• Concrete Network: Stained Concrete--The Art of Acid-Etch Staining