Paint is a wonder in many ways. It starts as a liquid. Then with a bit of chemical wizardry and proper application, it will turn into a solid layer that will protect and beautify your home or business place.
The chemistry of the curing process, and the properties of the paint when it dries, is a discussion for another day. Our concern today is how to get the paint to properly adhere to the substrate we are trying to protect. The first step may be a thorough cleaning of the surface, but often that isn’t enough.
If the surface is new wood or cement, it should be be porous enough for the paint to get a grip on. Perhaps too much so. Fresh wood will actually draw the solvents into the surface, causing the paint to ″dry″ before it has had a chance to properly ″cure″. Other surfaces may not be porous enough for the paint to properly adhere. This can allow moisture to get between the surface and the paint layer, causing mold or other damage to the substrate.
The solution is actually a pretty simple one, primer.
Primer is a type of paint that has the property of being able to stick to various substrates (different surfaces call for different primers). The primer is not only designed to adhere to the surface, but it can give it degrees of protection all its own. Especially useful on paper-covered gypsum board is a primer that contains a biocide that will inhibit the possibility of mold growth.
Primer by itself is usually not very durable. But that shouldn’t be a concern because as soon as it dries it will be covered by your paint. And paint sticks very well to primer!
Primer can be tinted to be match the color of your top-coat. If you are changing from a dark to a lighter color paint, this can reduce the number of paint coats that your project will need for complete coverage.