Formulated paint products that used to prepare surfaces for the finish coat of paint are Primers. Primers job is to adhere to the substrate while creating a uniform surface. The surface is ready to receive paint. Primers also act to seal pores in wood and other permeable materials as well as to prevent stains, knots, and wood tannins from bleeding through. Primers can make your paint job last longer and look better when it is properly applied.
When to Prime
Before painting, every unfinished surface, such as wood, drywall, metal, and concrete are should be primed. If you skip this step, the results are usually disappointing. Paint applied to unprimed surfaces tends to peel, crack, and chalk more than paint applied to properly primed surfaces. You have to remember that you need to always scrape and sand any deteriorating surfaces before applying primer.
Your paint job is no better than the preparation. Make sure to sand or declass the surface first when you paint over interior oil based woodwork with latex. Adhesion problems may happen when you Paint over multiple layers of oil-based paint on the outside of older homes with latex paint. Therefore, in that situation, you are better to continue using oil based house paint.
Applying primer may seem like unnecessary, but it actually saves money as well as time. A good coat of primer improves paint’s hide, or ability to cover, reducing the number of coats that are necessary to achieve a smooth finish. Primers can be tinted to match the paint color. Tinting improves the primer’s hide and smooths the transition between primer and topcoat.
Types of Primers
Primers have some types such as oil, shellac, or latex- based formulas. Each type has differing properties and uses a different solvent for thinning and cleanup, and when you choose it, you need to match largely a matter of matching the primer’s characteristics to the project at hand.
These slow drying primers release volatile organic compounds in the air and require mineral spirits for cleanup and thinning. They produce a very smooth finish that does the best job of filling pores in bare wood while not raising the grain. Oil primers also provide a good barrier to keep tannins from certain woods from bleeding through.
Oil primers are good to use for unfinished wood, previously varnished wood, Redwood, cedar, or other woods that tend to bleed tannins. Heavily weathered wood. Over existing paint that is failing due to chalking or cracking.
These fast drying, water-soluble primers have come a long way in recent years and are now available in low and no-VOC formulas. Latex primers are not as brittle as their oil or shellac- based cousins and provides a more flexible finish that is resistant to cracking.
This makes them suitable for priming bare softwoods, though test them first to see if they raise the grain or allow resin to bleed through. Latex primers are the best choice for unfinished drywall, since they act to even out the texture and sheen between the wallboard and joint compound.
They also allow water vapor to pass through, which can make them less likely to peel. You can use latex primers on unfinished drywall, bare softwoods like pine, Masonry such as brick or concrete block, and Galvanized metal, after proper cleaning.
Oil/Latex Paint Test If you’re not sure whether the existing paint is oil-based or latex, wipe a small area with a clean rag saturated with denatured alcohol, paint DE glosser, or non-acetone fingernail polish remover. If the paint is oil-based, it will not be affected. If it is latex, some paint will come off on the rag or the surface will become tacky.