What is Primer and Why Does It Matter?

calander Feb 14 , 2020 user-icon Nash Painting

If you’ve read enough painting blogs or talked to any professional local painters about their craft, the word “primer” has probably come up at least once. But what is primer, exactly? Why is it important? And do you have to prime every time? Let’s break it down.

A Primer on Primer

Simply put, primer is an initial coating that’s applied to a surface prior to painting. This material “primes” the surface to be painted, providing a buffer between the bare surface and the paint. Primers are generally composed of three parts: synthetic resin (about ⅓), solvent (usually ⅔), and an additive agent (only about 2-5% of the mixture). Generally speaking, primer is white, though some products are tinted.

Primer vs. Paint

The main source of confusion surrounding primer is in how it differs from paint. After all, both products come in the same-shaped cans and are designed to coat a given surface. But while paint and primer are similar in many ways, they’re distinguished by chemical composition. In layman’s terms, paints are pigment-based while primers are resin-based. Resins actually penetrate a surface, filling its pores. Therefore, primer acts as a sealant. The pigments in paint do not share this quality, but instead provide color and add durability.

Why Does Primer Matter, Anyway?

So, we’ve now briefly discussed what primer is and how it’s different from paint. But we still haven’t explained why commercial and residential interior painting companies deem it so important. Of course, the information above might already give you an idea.

As mentioned earlier, primer acts as a bonding and sealing agent. By soaking into the surface, the primer creates a barrier that makes it easier for the ensuing paint to stick. Without this initial undercoat, some of the paint itself would get absorbed into the surface. This can damage the surface and reduce the quality and appearance of the paint job. So, the benefits of primer are threefold: it protects the underlying surface, helps the paint stick, and increases the paint’s durability.

Exterior and interior painting contractors may also use different types of primer on different types of surfaces for maximum protection and paint adhesion.

Is Priming Always Necessary?

In short, no, priming isn’t always a must. Some occasions don’t necessarily call for this step. For instance, if you’re touching up a previously painted surface that’s in good shape, you or your local interior painters should be fine simply cleaning and painting over it. Otherwise, though, priming is an important measure for achieving the best results.

As a rule of thumb, you should always prime before painting:

  • A new, never-before-painted surface
  • A porous surface
  • A worn-down surface
  • Over a different color (especially a darker color)
  • With a flat finish over a glossier finish (so the shine doesn’t poke through)

Additionally, there are other instances when priming is a good idea. Ultimately, when in doubt, break the primer out.

Optimal Prime

Just because you don’t see primer doesn’t mean it’s not a valuable player. Indeed, behind just about every quality paint job is a quality coat of primer. And now you know why. Still, you might struggle to figure out how much primer you need, what kind you need, or how to properly apply it. If that’s the case, get help from a reliable, experienced Nashville painting company. At Nash Painting, we’re always in our prime. To learn more about us, our services, and our values, call us at (615) 829-6858 today!