Recommended Surface Prep
Previously Painted: Remove all dirt, chalk, efflorescence, loose or peeling paint and other surface contaminants by power washing and scraping. Patch holes and other surface defects with the proper patching materials. Patched areas may require additional primer coats to even the final coat. Replace caulk which may be missing or in bad repair.
New Work: #470 Block Filler must be worked into surface pores while wet with a long nap roller, and should be back rolled when spray applied. On lightweight or very porous blocks, spread #470 Block Filler at 40.50 square feet per gallon. The pH of the blocks must be below 10 and all efflorescence must be removed prior to painting.
Efflorescence can be removed with a solution of muratic acid, or by using a wire brush, high pressure cleaning, or sandblasting. Muratic acid must be neutralized with water prior to painting.