Basement Flooring Guide

Acid staining concrete results to having deep, rich translucent tones, nothing like paints or coatings that deliver a solid, opaque effect. Depending on one’s preferred color and the techniques applied, the resultant looks can vary from that of polished marble or natural stone to that of tanned leather and even stained wood. The result is a consequence of the reaction of acid stains with the lime content of concrete. Acid stains are unable to penetrate a sealed or painted surface to react with lime, meaning that a painted or sealed concrete surface can’t be treated with acid stains.

Do you need to take away the paint or sealer from the concrete surface before using acid stain over it?

Not really!

The availability of most recent acrylic polymer modified concrete enables you to apply a thin layer (1/8inch thick) of concrete over the present sealed or painted concrete surface with least surface preparation. Here are the essential steps you should take for applying a layer of these polymers for subsequent acid staining over an already painted or sealed concrete surface.

a. Run a sander with 60grit sanding screen all over the place. The sander should be used for a minimum of one hour per thousand square feet. That would ensure the paint or sealer to remain bonded with the substrate.
b Using a mild detergent rinse the surface and let it dry completely.
c. Apply a liberal coat of acrylic primer, Cp1000.
d. Allow this primer to cure overnight.
e. Apply a second coat of acrylic primer, Cp1000. The second coat is just to moisturize the surface.
f. As the primer gets clear and dry to touch, it’s prepared to accept the concrete overlay.
g. Consider using polymer modified concrete overlay, Pentimento, 1/8inch thick. It is a retrievable concrete overlay for getting an extremely smooth concrete finish.
h. After a gap of 24 hours of curing or polymer concrete overlay, it’s time to apply acid stains.
i. Patinaetch acid stain should be sprayed at the rate of 250ft2/gal. Give it time of 2-3 hours to react with lime in the concrete, followed by the normal process of getting rid of residue. Make sure that residue is thoroughly cleaned before using ammonia to neutralize the surface.
j. Let the surface get dry completely, giving it at least 24 hours, and then seal it with one coat of water based epoxy, Perdüre E32 followed by another coat of water based polyurethane, Perdüre U46.

Application of Pentimento does not take care of the problem of moisture. It will be very desirable to have a MVER test done before applying Pentimento and acid staining with Patinaetch. At times it may prove to be better and cost saving option to go for concrete resurfacing than grinding off the paint or sealer. Even if they are removed from the surface, there is no surety of your getting the desired results after acid staining.