Step 1
1. Surface preparation 1.1 New surfaces must be dry, clean and free of other contaminants; good surfaces should comply with ISO 8504. 1.2 For coated surfaces, water-jet at WJ3 (NACE No. 5/SSPC-SP12), or clean with power tools, or grind the concrete surface rough with power tools before painting. 1.3 For concrete, remove the weak surface layer completely. The best method is shot blasting, which fires round steel shot at the concrete with air pressure to remove the poor top layer while vacuuming up the debris. Alternatively, wash with 10% hydrochloric acid (HCl), made by mixing 3 parts water to 1 part acid (pour the acid into the water), stir gently, pour it over the concrete floor, leave it for about 5-10 minutes, then rinse 1-2 times with clean water. While rinsing, scrub with a stiff plastic-bristle brush to remove all dirt (do not use a metal brush). Once you are sure the surface is clean, let it dry completely before painting
