About This Project

If the adhesion of old paint has been weakened, covering it with today’s acrylic paint might pull it off and make surfaces look worse. Acrylic paints «dry» quickly, but they «cure» over many days. As they cure, by a process called «co-polymerization,» the paint film shrinks and can detach weaker layers of old paint.» That’s why, after adequate preparation of old paint surfaces, an oil-base primer is recommended. Oil-base paint doesn’t pull old paint, and it will resist the pull of an acrylic topcoat. Adequate preparation must include «feathering» the sharp edges of old paint where many layers have fallen away because it’s impossible for any paint film to maintain its thickness around a sharp edge. Incidentally, that’s why skilled painters sand the sharp edges of new construction millwork trim.