Removing various paints from a concrete-surface can be a lot of work depending on what type of paint is covering the concrete-surface and how much of it is on the surface. If you are trying to get rid of a paint spill or splatter the process is much easier than trying to get rid of a completely coated area from the entire surface of a concrete floor or concrete patio.
Remove Paint-Spills or Paint-Splatter
Paint-spills and splatters are fairly easy to get rid of from a concrete-surface regardless of the type. This method works for latex, oil or epoxy paints.
Soak a rag with paint-thinner. When working with the thinner be sure to work in a well ventilated area.
Lay the paint-thinner soaked rag over the paint spill or small drops of paint.
Allow the rag to sit 3 to 4 hours.
Remove the rags and scrape the softened paint away.
Rinse the area thoroughly with plain water to remove of any thinner residue.
If any paint remains on the concrete-surface, use a wire brush to loosen it and reapply paint-thinner soaked rags.
If latex paint was used on a concrete-surface it is fairly easy -- because latex does not bond well to concrete. Latex will lift, bubble and peel. Power washing will remove the paint from the concrete-surface.
Oil-paint is slightly more difficult to remove from a concrete-surface than latex.
Use a broom to apply a coat of mineral spirits or paint-stripper on the concrete-surface.
Allow the mineral spirits or stripper to sit for an hour or two.
Power wash the surface to remove the loosened paint.
An epoxy-paint is the most difficult paint to remove from a concrete floor, patio or other concrete-surface. There are several methods that are quite effective, some are more difficult and complicated than others, but all are effective.
When removing epoxy paint from concrete-surfaces: Wear protective goggles, respirator, gloves, protective shoes and long pants. Work in a well ventilated area. Do not these harsh chemicals with children and pets present.
Use a sandblaster to remove the epoxy from the concrete. Sand blasters can be rented at hardware stores and home improvement stores.
Mix diatomaceous earth with paint-stripper to form a slightly watery paste.
Apply the mixture to the floor in smaller more manageable sections, approximately 3' x 3".
Allow the mixture to sit for 20 to 30 minutes.
Use a plastic putty knife to scrape the old paint away.
Wash the area well with detergent and water. Use a stiff broom to scrub the concrete-surface.
Reapply the paste if any paint remains.
Use an acid based etching product or a floor grinder to strip the epoxy paint off of the concrete. If you use an acid etching solution or a floor grinder, the concrete will need to be repainted or sealed as soon as possible. Etch or grind the surface of the garage floor in smaller more manageable sections. Floor grinders can be rented from hardware stores and home improvement stores.
Acid based etching products are dangerous to work with and are best left in the hands of an experienced person. If you are not familiar with working with acids leave this option off of your list.