How to Clean Efflorescence for Painting

Don nitrile rubber gloves, as the chemical you use to remove efflorescence is very hazardous to your skin and these gloves are acid-resistant. Protect your eyes with chemical splash goggles, and wear a chemical-resistant apron to avoid causing damage to your clothing.

Apply water to the area that bears the efflorescence. Note whether the efflorescence dissolves in water. If so, use a harsh bristle brush to scrub it away. Consider additionally mixing water with a mild household detergent and scrubbing the masonry area with this solution and a bristle brush.

Add one part muriatic acid -- also known as hydrochloric acid -- to 12 parts water in a bucket, following the manufacturer’s instructions, as muriatic acid prepares your masonry for painting by removing old paint, dirt and other coatings. Apply several applications of the mixture on the area of the efflorescence instead of dousing the efflorescence-covered wall all at one time, as multiple applications tend to be more effective. Do this if the water and household detergent you used in Step 2 are not effective at removing the white crystals from your wall.

Rinse the muriatic-water mixture away with clean water.

Purchase a sandblaster if the muriatic and water mixture is not successful at removing the white crystals from your masonry. Follow the device manufacturer’s instructions to strip the surface of the masonry on which the efflorescence is a problem.