At Celtic Commercial Painting, we know primers and sealers are two of the most powerful tools in the professional painter’s toolkit. Both products are the first coating on a surface and prepare it for the topcoat. They each have their own unique qualities and when to use them depends on many variables.
Primers are formulated with an excess of pigment and dry to a slightly
rough surface. This allows the following coat paint to attach firmly. Primer
also fills small pores, making them nearly invisible to the naked eye once the
final layer is applied. For instance, when new drywall is installed, it often
has little pits in the mud or fine grooves left from sanding. The primer fills
in these imperfections so that when the paint is applied, they won’t be seen.
Sealers, on the other hand, are a special type of primer. They are
formulated to make very porous surfaces non-porous and may be clear, allowing
the underlying structure to show.
Subsequent topcoats appear more even and provide a uniform gloss to the
finished product. Take a concrete floor for example. Once the floor is
polished, a sealer is applied to maintain and protect that polish. Or, if you
have a raw wooden door, sealers contain ingredients that block the natural
tannins in the wood from seeping through and discoloring the finish.
While it’s not the end of the world if a primer or sealer isn’t used,
if you want the highest performing, longest lasting and best looking finish
possible, you need to use one. This applies to metals, masonry and concrete,
drywall, plastics, and wood of all types. Primers are generally latex or
oil-based, while sealers may be oil-based, resin or epoxy. Which one to use
depends on the structure and the desired finish. For us, primers are an
essential step.