The Importance of Priming Before You Paint
The purpose of priming is to seal any absorbent surface and to provide a good bonding surface for the paint to stick to. In addition to good adhesion, priming can also save paint, since you will usually need to use less paint on a properly primed surface.
Begin the priming process by ensuring that all dirt, grease, and loose or flaky paint has been removed from the surface. If the wall surface is stained, or damaged by smoke or grease there are special stain blocking primers, which are available. If you find that you keep painting a wall only to have a stain poke through, the key to getting rid of that problem can often be to prime the wall.
Generally all bare woods should be primed before painting for a finish coat. The reason for this recommendation is that often the wood is “thirsty”, and will absorb a lot of paint when initially painted. This can ruin the finish, not to mention use a lot of extra paint.
Another common wall material, which should be primed before painting, is new gypsum drywall. Most drywall surfaces are simply a type of cardboard. This type of substrate is usually very “thirsty” for paint. Often if you fail to prime new drywall before you paint, it may take three or more coats of paint to obtain a proper finish. Priming can reduce that down to two or one depending on the paint and the primer that you choose. Failing to prime new drywall and then painting it with multiple thick coats of paint can also serve to change the texture of the drywall finish and create a gummy finish because of the thick paint coat.
Another great reason to prime a wall is if you are changing from a very dark paint to a light color. You can obtain a light colored primer, which will seal the dark color already on the wall and will lighten it so that you will need to apply less paint as a finish coat.
No matter what type of surface you are going to paint, obtain the right type of primer for the surface you are working with. Primers are made for wood, drywall, acrylic, oil, masonry, and even clear coats. Always make sure that you read and follow the manufacturer’s application instructions before you begin to apply the primer.