30 years ago the basement was painted with latex paint on concrete block. Now I want to do it again as there has been some calcification in the concrete between the block. That has to be wired brushed. My question to you is – Is there any special preparation that I should put over those areas before using a latex paint again, or should I just give it a heavier coat in the affected areas.?
Wire brush to remove any loose paint, etc. Wash the affected block with either a masonry cleaner or vinegar and water. A little acid will help remove and neutralize the calcification. Rinse well with fresh water and let dry. Now prime everything with a good universal acrylic primer.