Proper Painting Sequence
Whether painting new walls and trim or previously painted surfaces, always begin with a primer.
What is the right sequence for applying paint, both over new wood and over surfaces already painted? Should you always prime new work with oil-based paint regardless of whether the new finish is oil-based or latex? And should you always use an oil-based primer over old paint even when you’re not sure if the old paint is oil-based or latex?
Bill Smith, via e-mail
Brian J. Doherty, a painting contractor in Richmond, Virginia, replies: On new wood, most pros like to use an oil-based primer because it penetrates the wood. This choice is fine, but a latex-acrylic primer also works well, no matter what type of finish paint you choose. Oil paints and primers usually settle to a glasslike look and feel. Although oil finishes adhere to latex primers just fine, they tend to look a bit odd because latex primers (and latex paints in general) leave ridges from the brush that can show in the finish coat. Regardless of the primer, don’t forget to sand lightly between coats.
When dealing with questionable old paint, the professional painters that I know start with an oil-based primer. Oil primers should stick to anything; then you’re free to put on a top coat of either oil or latex paint.
Modern 100% acrylic primers, such as Benjamin Moore’s Fresh Start (www.benjaminmoore.com) supposedly adhere to anything. I’ve had mostly good experiences with these products, but to be honest, I’ve known situations in which an acrylic primer failed. So for now, my recommendation is to apply a top-quality oil-based primer over an unknown finish, then to apply whatever you choose for a finish coat.