Self Etching Primer Vs Epoxy Primer: Which is Better Before Paint?

A primer, before applying paint, brings immense benefits along with successful achievements. The purposes of a primer are vast and among them, the primal one is it offers intensive adhesion which lets the paint stick to the surface tightly. An undercoat of a quality primer before applying your desired paint makes the paint look smooth, even, and seamless. Besides that, some primers are for preventing rust and preparing the surface for applying paint.

But people get confused when it comes to choosing a quality primer. Even they are most interested to learn which one results better between Self Etching Primer Vs Epoxy Primer as both primers are top-notch. But you should learn this minimum fact about these primers they are for different purposes even though they both play important roles while painting something. Besides, their features include longevity, easy-applying methods, and mostly great adhesive power.

Self Etching Primer Vs Epoxy Primer

As priming is the ultimate job of both of these primers, you might choose only one between self-etching primer and epoxy primer. But in some cases, you might require both of them. Therefore, we are going to provide a deep discussion on these primers and their comparisons so you can have a better understanding of them.

 About Self Etching Primer –

You can clearly learn from the name that self-etching is basically a primer. This primer provides a coating and the purpose of this coating is slightly different from other coatings of other types of primers. Self-etching primer is meant to apply on metal-based surfaces only. The reason behind this is its primal ingredients are zinc and phosphoric acid and this combination is used mainly to prevent rust to attack metal-based surfaces or materials.

There are different purposes for these ingredients. The acid is supposed to etch the metal surface to prepare it for the zinc to adhere to the surface properly. Thus the primer protects a metal-based surface from rust and to some extent intensive corrosion as well. No matter what self-etching primer you bring home on purpose, all of them provide more or less the same benefit. However, don’t expect the primer to remove the rust that is already on the metal surface because it only can thwart rust from further damage.

What is Selfe Etching Primer

Apart from that, a coat of self-etching primer is not able to abolish or strip off the rust that is already there beforehand. As the color of this primer has a grey-like tint, you can distinguish the coating easily. You also need to have some basic ideas about the use of this primer before you apply it to some material. First of all, as we have said already that only metals are the suitable material for this primer, the metal should be bare and free of other things before applying it to get a fruitful result.

Some people remain in confusion asking if it is possible to paint over self-etching primer coating. Painting directly over self-etching primer coating is prohibited in the instructions of most manufacturers. In cases where you need to paint over the undercoat of self-etching, use another quality primer before painting to save the undercoat of self etch from being futile as a result. A self-etching primer coating then another coat of urethane primer and then paint over it should be the process while it is a metal.


  • Provides a great pigmentation of zinc and phosphoric acid and it’s less expensive
  • Prevents rust to happen on your metal-based vehicle or surface for a long time
  • The tint of the coating offers a distinctive result and a single coat of it is enough
  • It comes in a spray can that makes it easier to use and quickens its performance
  • A certain positive result can be gotten if you follow the right procedure for using it


  • It requires to be top coated and filled or another coating of another primer before applying paint
  • A little time-consuming and not hassle-free

About Epoxy Primer –

Epoxy primer is one of the known primers that most people choose. Because this primer not only primes the surface but also fills crevices and dents, it is popular both among professionals and amateurs. Epoxy primer is built with high-end ingredients to provide maximum adhesion. Using an epoxy primer before painting a surface would be the greatest idea as it fulfills the utmost requirements. It provides a transparent and a little heavy coating to create a secured base on a surface.

From rescuing the surface from UV rays and heavy or windy rainfall to keeping it durable for many years, epoxy primer is well rewarded for these. Besides, this primer is able to make a perfect base on bare steel or metal materials. For painting purposes, this base offers fitness for the paint and assists in giving a tight and nonporous finishing. Another important aspect of this primer is it works as a sealer as well.

applying Epoxy Primer

For waterproof materials, this primer puts the perfect effect on the surface by creating a base that cannot be penetrated at all. This base also helps the material to avoid corrosion and rust to the greatest extent. We found this primer with intensive adhesion works wonderfully on heavy-duty materials that remain outside and suffers from natural calamities and disaster every now and then. Another best thing about this primer is you don’t have to sand it after applying it.

As epoxy primer is a great sealer, it provides the strongest coating and increases the adhesion along with the adhesion of paint. Besides, you can just directly paint over the base of epoxy primer, no in-between primer is needed. On top of that, there are fewer restrictions and rather easy instructions to use the epoxy primer. However, this primer, according to its top-notch features, demands a topcoat to be more attentive to its duty. Read Also: Powder Coat Vs Epoxy Paint: Difference & Which is Better

Pros / Advantages:

  • Provides optimum guarantee for a solid base as a sealant and primer at the same time
  • The pleasure of doubling the adhesion of paint by using epoxy primer
  • Protects the surface from rust and corrosion and provides durability for many years
  • It is a master of filling gauges, and also easy to strip off if needed
  • Can tackle the harsh weather outside without becoming patchy or creating scratches marks on it

Cons / Disadvantages:

  • It also requires a waterproof top coat for a better performance
  • Very much pricy than other ordinary primers

Epoxy Primer Vs Self Etching: Which One is Better?

As we have already given you some basic ideas about self-etching primer and epoxy primer, you might assume that their comparison is an obvious occurrence. Primers are meant to prime and prepare the surface to increase adhesion for other coatings like paint and topcoat. But there are some legit and distinctive differences between self-etching primer and epoxy primer. Some people mistake these two for the same type of primer. But they are clearly not and the following difference between self-etching primer and epoxy primer will embody this idea to a greater extent.

Coating Texture:

Coating Texture

The first thing that arrives to mind when comparing self-etching primer and epoxy primer is the texture of their coatings. Self-etching primer provides a very light coating. Therefore, it requires very little time to dry as well. You can tell by the tint of the coating that it is self-etching primer because they provide a grey color. This color is the influence of zinc in the primer. One thin coat of self-etching primer and you are good to go. You don’t have to put another coating of the primer and waste it.

On the other hand, epoxy primer is not as light as a self-etching primer. Its coating is heavy-duty and puts a thicker coating than the coating of self-etching primer and cures late. This coating is more transparent and provides more adhesion than any ordinary primers. Besides, the texture of epoxy coating works as a sealant to provide more benefits to the surface.

Versatile Motifs of Primers:

Self-etching primer has its own motif. Its main purpose is to prevent rust from bare metals. Therefore, you can only use this primer on bare metals. Also, as we have mentioned before that this is not a primer that ceases rust, you need to clean the scale of rust from the surface of the metal at first. And then you should apply the primer to resist rust and corrosion from further invading.

Then again, the epoxy primer has some solid purposes. Besides resisting corrosion and rust, this primer is an expert in filling crevices and dents and can be used on metal, steel, or concrete surfaces. Therefore, we can see some certain versatile features of this primer. This primer also enhances the adhesion to get along with the new coating. You can also sand this primer as per your wish which leads to the door to versatile use of an epoxy primer.

Painting over Primers:

Painting over Primers

Most of the primers are used so they can get along with the extra coating of paint in order to provide durability and sustainability. But self-etching primer does not allow the coating of painting directly on it. You need to put another urethane primer or sealant before applying paint. Otherwise, the result will not be good. Some suggest that it is okay to use epoxy primer after the coating of self-etching coating.

But epoxy primer is heavy-duty and it might affect the self-etching primer, therefore some professionals don’t suggest the idea. However, in the case of epoxy primer, you can definitely paint over it without any restriction, unlike self-etching primer. Also, no extra primer is needed to apply before putting the coat of paint on epoxy primer.

Providing Topcoat:

Providing Top Coat

Topcoat is a serious fact that measures up to some extent which primer is better in between self-etching and epoxy primer. If you topcoat self-etching primer, it enhances its performance from that moment. Then it will prevent rust and corrosion more effectively than any primer. But applying topcoats has several benefits, it requires hassles as well.

On the other hand, the epoxy primer doesn’t necessarily require a topcoat. It can work pretty well even without a topcoat. On top of that, epoxy primer is so thick and heavy-duty in nature that it almost provides the same benefits as a topcoat does.

Price and Apply Method:

Another important aspect is money does matter. Self-etching primer has some limited but efficient purpose and it is of lower cost. On the other hand, the epoxy primer has several benefits at a time but it is extremely costly.

Self-etching primer comes in a spray bottle and is super easy to apply. Besides, takes very little time to cure and a single coat works effectively. No mess will happen rather a quick job can be expected. But to apply the epoxy primer, time and other materials are required. Besides, the process is a little messy for sure. Read Also: How to Get Smooth Finish with Spray Paint [In 6 Easy Steps]

So, Which One Is Better?

From the overall view of the comparison between epoxy primer and self-etching primer. It is clear that both primers are made to fulfill certain aspects of their own and they both are successful in it. Choosing one between these two is not hard once you learn what you need the most to do your job.

If you just want to preserve your bare metal surface from rust and have a little budget then self-etching is a go-to primer for you. On the other hand, if you have great expectations and want your primer to prime, fill, and prevent rust at the same time, then an epoxy primer is the one for you. Also, great benefits require great cost, so, you should keep that in mind too.

FAQs –

1. Is self-etching primer required before applying epoxy primer?

It is not necessary that when you are applying epoxy primer, you need another primer. All you need is to clean the surface properly and evenly so epoxy primer can adhere to the surface suitably. But if you are planning to apply self-etching primer at first on a metal surface, provide a topcoat. Self-etching primer requires a topcoat more than epoxy primer does. So, it did not require applying self-etching primer before applying epoxy primer.

Final Opinion:

The epoxy primer is ideal if you want a flawless finish on your bare metal body or if your body needs some work. You can sand and fill the layer as needed. Watch the recoat window on your product. Filler and epoxy primer can be added during the recoat period (usually a few days). The original layer will have to be scuffed if you let your project sit for a week.

Those of you who are weekend warriors may have to take this additional step but it’s a small price to pay for the freedom of working on your own time and not having to worry about rust.

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