Primer and Sealer Tips from the
Rohm and Haas Paint Quality Institute

Falls sun-filled days and clear, cool nights set the stage for great outdoor painting conditions. But before you brush on that first coat of paint, review these tips from the Rohm and Haas Paint Quality Institute. Just like quality paint, primers and sealers help to improve the appearance, performance and longevity of a finished paint job. The necessity of using either a primer or sealer varies from job to job and surface to surface.

Primers perform several valuable functions. They help the topcoat adhere better to the surface that’s being painted. They do this by making the surface more uniform and accepting for the top coat, so that when the paint is applied, it can get a better “grip” than it would on a bare surface. In addition, primers help give the finished paint job a more uniform appearance in terms of color and sheen, thereby making it more attractive. This is especially true when the surface being painted is porous or uneven. Finally, some primers help prevent stains from coming through the paint from the surface below.

While primers are generally pigmented, sealers are not. The role of a sealer is to seal a porous surface like weathered concrete or stucco so that a finish coat can develop a uniform sheen or gloss. Sealers also help protect the finish coat on masonry from efflorescence which is a white, salt-like residue and to help seal out moisture.

No matter what your painting project this fall might be, remember to use a primer or sealer in these circumstances:

1. When painting new wood or any other surface that has never
    been painted before.

2. When repainting a surface that is uneven or badly deteriorated.

3. When repainting a surface that has been stripped or is worn down
    to the original surface material.

Just like paints, primers and sealers perform best when the surface is properly prepared. Regardless of the application, the surface to be primed or sealed should always be clean and free of dirt, loose or flaking paint and other contaminants before the primer or sealer is applied.