What Is Primer and Do I Need One or Two Coats?

Person using a hand rolling to apply white house paint/primer on prepped wall

Taking on a small DIY painting project doesn’t seem like a big deal. However, even a small painting project requires an investment of your time and effort. Before you get started, it’s important to make sure you have everything you need to get the job done right the first time. This includes understanding whether you need to apply a coat or two of primer to the surface you paint. Since the type and condition of the surface you paint will determine whether one, two, or no primer is needed, it’s important to understand how using a primer can make your painting project a success.

Before we go into detail about how, when, and why a primer should be use, we’ll review what a primer is and the purpose it serves. Primer, sometimes called primer paint, isn’t technically paint. Primer’s main purpose is to serve as both a masking and adhesion agent.

If you’re looking to cover a dark paint color with a lighter color, primer helps mask the old color so the new color appears closer to its true hue.

Primer can also help new paint adhere to a surface better, since certain paints don’t bond well to all surfaces. Primer also helps fill in holes and cracks on porous materials (like wood or concrete), and helps paint bond to slick surfaces like aluminum. Here are some examples of how a primer should be used on different surfaces, depending on condition:

  • One Coat—New drywall, raw wood, subtle color changes.
  • Two Coats—Damaged drywall, stained walls, rusty metal.
  • Three Coats or More—Wood paneling, bold color changes.

Related Topic: Factors to Consider When Choosing Exterior Paint Colors

How Much Primer You Need Is Based on What You’re Painting

No two painting jobs will be the same, but there are some general guidelines that you can follow to make sure your project goes as smoothly as possible. Let’s review some of the main situations and materials you’ll encounter and how to deal with each.

As was mentioned briefly above, one of the first things to consider is what you’re painting. Materials like unfinished wood and untreated drywall can absorb paint coats, so you’ll want to make sure you use at least one or two coats of primer to make sure the porous surfaces will be ready for your paint. If you’re going to be working with a material like metal or finished wood, the chance of absorption is less, and you will only need one coat of primer. If the metal is rusty, two coats will prevent the paint from peeling.

Another important factor to consider is what kind of paint is already on the surface you intend to paint. If your surface has no paint, white paint, or is a light color, you might think that you’ll be fine without primer. Although you might be able to get away with it in some cases, it will be better for the overall health of your paint to put down a coat to make the adhesion of the paint a little easier. If you are trying to cover a dark paint, you will probably want to apply two or more coats of primer to really give yourself a fresh workspace. Darker colors will make it hard for a new paint color to be properly displayed.

Although each surface and base color will be different, it’s a safe bet that two coats of primer will achieve any priming goals you have.

Do You Really Need Primer?

Yes, especially for drywall or bold color changes. Although primer may seem like an added expense to your paint project, in the end, it saves you money because primer is much cheaper than paint. New drywall, for example, soaks up paint like a sponge. What might take three or four coats of paint can be accomplished with one coat of primer and maybe two coats of paint.

Don’t even think about painting wood paneling without a few coats of stain-blocking primer. Without a good primer, it could take upward of six coats of paint to cover the wood grain. And even then, the grain still might show through after the paint cures.

What Primer You Should Use

You’ve probably figured out by now that because no painting project is identical, there isn’t a one-size-fits-all primer. Before you put brush to any surface, you’ll want to look at a few different primers to determine which one fits your needs.

Sherwin Williams has multiple options for specific materials, and it would be a good idea to look through their offerings based on your needs. Another thing to consider is the base of the paint you are using. If you plan to use an oil-based paint (like an enamel paint), you’ll want to make sure your primer is also oil-based. The same can be said of water-based paint and primer, however water-based paint can be used over oil-based primers.

Lastly, consider the location of your project. Although it might seem like there shouldn’t be a difference, Behr and Sherwin Williams have options that are suitable for interior and exterior surfaces, but some primers are only rated for interior use. Make sure you purchase the correct product.

Getting Started

If you enjoy painting, a small DIY paint project, or two, is no big deal. Understanding when and how to use primer can help ensure those small paint projects turn out looking good. However, when it comes to bigger paint projects, it’s best to hire a pro. A professional painter has the right tools, knowledge and experience to ensure the job is completed on time and looks great too!

If you have questions, or a painting project you need help with, contact your local painting pros at Five Star Painting. We offer a variety of interior painting services that can help refresh the interior and exterior of your home. To learn more, call us at (888) 261-3633 or book a free estimate online.