Author Brian Santos

Q. How do I know when to use a sealer?

Brian Santos: Use a sealer before painting porous surfaces such as these:

 

• Any unpainted surface, including new plaster, drywall, and old woodwork that has been stripped.
• Bare open-grained woods such as oak and maple.
• Bare woods, such as redwood, that bleed through or discolor paint.
• Large areas of wallboard joint compound or patching plaster.
• Masonry surfaces like unglazed brick, cinder block, and concrete.
• Metal surfaces; use an oil-based primer-sealer with rust inhibitors to prevent corrosion.