Primer Surfacer Vs Primer Sealer: Key Differences!

Auto enthusiasts can be divided into two camps when it comes to working with primer surfacer vs primer sealer. For the most part, the average car owner is oblivious to the finer points of auto primer varieties. If you are painting your car and want to choose between primer surfacer and sealer, forum after forum, you’ll find discussions on the topic.

Maybe you’re just getting started with car painting want to know the difference between a primer, sealer and a surfacer. You’ve come to the right place. In this article, we’ll cover right from the primer basics to the differences between a primer, sealer and a surfacer, when should you apply each type, and when you might not need it.

What Is a Primer Surfacer?

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The purpose of using a primer surfacer is to prepare the surface for sealing with a sealer and apply the basecoat paint. Primer surfacers are formulated with fillers and additive agents to fill scratches, prevent rust formation creates a smooth surface for even coating.

The main reason to use a primer surfacer is to ensure safe and maximum coverage of the sealer and the basecoat. Some common types of primer surfacer are polyester and urethane primer surfacers.

What Is a Primer Sealer?

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Rust-Oleum 249321 Primer Sealer Gray Aerosol 12Oz, 12 Fl Oz (Pack of 1), Grey, 11
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The purpose of using a primer-sealer is to seal the prepared surface and to create a better bond between the primer and the basecoat. A primer-sealer provides adhesion that helps basecoat adhere to the primer surface, minimizing the chance of topcoat/clear coat from running.

Thus, primer-sealers increase the durability of your basecoat and topcoat paint job. Some common primer-sealers are urethane, epoxy, enamel, and lacquer sealers.

What Is the Difference Between a Primer Surfacer and Primer Sealer?

Both primer sealer and the surfacer is a subtype of primer. Some primers are used both as a sealer and surfacer by mixing the catalysts (activator and the reducer). On the other hand, a sealer can be used in conjunction with or as a substitute for primer.

The following are the common primers used both as sealers and surfacers to prepare the bodywork for painting.

Is Primer Surfacer and Primer Sealer the Same Thing?

Primer surfacer and primer sealer is not the same thing. Many people often use them interchangeably, forgetting that both primer subtypes have different roles. So, what is the difference between a primer surfacer and a sealer?

The practical difference between the primers is the composition and the filling capabilities. A primer surfacer is formulated with fillers, pigment, and solvents and is used for sanding and prepping the bodywork for sealing and coating.

Modern-day primer surfacers have filling capabilities. On the other hand, a sealer does not have any filling capabilities; rather, it is intended to promote the bond between the paint and the undercoat, prevent rust corrosion, and create a quality surface for the paint finish.

Is It Essential to Use a Primer Sealer On a Primer Surfacer?

Although primer-sealers are not technically required when working over epoxy or polyester primer, most high-quality repair and restoration shops recommend using a primer-sealer as part of their standard painting procedure.

They mix a 4:1 ratio of the primer surfacer with a primer catalyst containing fillers which serves the purpose of primer sealer.

Using a primary sealer is especially important if you plan to go for a drastic color change. It means the primer-sealer serves the purpose of sealing the old color perfectly so that it doesn’t show through the new color.

Do You Need a Primer Sealer or A Primer Surfacer?

Since most high-quality paintwork repairs use a primer-sealer, most companies (not just paint manufacturers) recommend using a primer-sealer after using the primer surfacer.

Primer surfacer and primer sealer are used together to provide the surface with a resilient foundation for painting. They’re both key products that work together as part of comprehensive paint protection and finishing system.

When to Use Primer Surfacer?

Primer surfacer is intended to fill in gaps, levelling off curved surfaces, and fill in small holes or imperfections. When should you use primer surfacer? Firstly, you use it for various reasons, including priming, sanding and prepping for your paintwork. Here are some ways to identify what type of primer surfacer you need depending on the type of various requirements.

Large paintwork

Epoxy primer surfacer is ideal for large paint jobs. It has self-levelling properties, and by mixing a two-part formula, epoxy primer can be prepared to prevent corrosions and provide the optimum adhesion for coating. If you have a small area to fill, polyester primer surfacer is ideal as it is a high-build primer surfacer. It has a higher and thicker consistency making it perfect for filling in dents and scratches while also sanding down easily.

Repairing and for touch-ups

If You are almost done with your painting, but you notice that you don’t like the way it looks. Do you throw it in the trash bin and start over? Not necessarily! You can use a primer surfacer to fix this situation, although it depends on how far through your painting process is.

Rust and moisture protection

On the other hand, consider using a Urethane primer surfacer in case of drastic colour change or when you need superior rust protection. Other than urethane primer, many professionals often opt for undercoat primer to lighten the surface and then apply a surfacer on it.

When to Use Primer Sealer?

Sealer can substitute for primer, or be used before any primer is applied to the substrate. Its purpose is to provide good adhesion between the new paint and the substrate. It can also recondition old surfaces that are not suitable for painting.

Hence, whether you are painting or staining, if your surface is not in good condition, use a primer sealer to give the paint or stain a strong surface to adhere to.

The Final Thoughts

If you have decided to repaint your vehicle, give it a new look, protect the existing paint from rust or simply revive and refresh the current state of your vehicle’s surface, you may be wondering if primer surfacer or primer-sealer is best suited for the job. Both options are perfectly viable choices.

That being said, there are certain situations where one would be more optimal than the other and choosing the right type of primer for your car paint doesn’t have to be an intimidating process, really. Think about the qualities you’ll want in a primer.

Is it great flow-out, easy application, or superb levelling? Perhaps you want a primer with great sanding properties and with minimal surface preparation or one with efficient moisture barrier properties. Hence, you should be choosing the primer type depending on your needs.

Are you confused about why one primer is better than another? Don’t worry because here at Fine Tuning Automotive; we’re always happy to help in understanding the primers that would meet your needs.

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