Epoxy Primer Vs Urethane Primer: Difference & Which is Better?

Paint without primer is almost like a knife without sharpness. The greatness of a primer is only known when you apply it to a clean surface to a get satisfying finish. A quality primer works like a canvas on any surface and most importantly increases its adhesion.

Thus people are mostly fascinated by finding heavy-duty primer before applying paint to their desired surfaces. Thinking about the demand for a high-quality primer, you will find several ones out there in the market.

Among all those qualitative primers, we saw epoxy primer and urethane primer stand out exceptionally. People really want to learn how the comparison between epoxy primer Vs urethane primer goes because of their versatility.

Epoxy Primer Vs Urethane Primer

Whereas epoxy primer is greatly known for its promising performance, urethane primer also does not lag behind to provide some charismatic adhesion to the surface. Both of these primers come with inexplicable sharp qualities to the greatest extent. Still, they are different from each other in various aspects.

Today, we are here to give you an in-depth description of both primers and observe their similarities and dissimilarities at the same time so you can decide which one to choose as per the situation.

About Epoxy Primer –

When it comes to learning about epoxy primer, there is actually a lot to gain about this tremendous primer. Epoxy primer is filled with components that suit your bare steel surface and give the rarest fine base to it. To get a perfectly finished surface, there is barely any alternative to epoxy primer. It is also used as a sealer besides providing a quality base. Also, this primer helps to offer a perfect seamless finishing to your car or any metal or steel-based surface.

As epoxy primer carries zinc-phosphate, you will get several benefits of this component. Apart from resisting rust and corrosion, this element in epoxy primer is capable of filling pores of the surface as well. You can also get the advantage of resisting oxidization by using a two-part of this primer. Another benefit of this primer is it protects the underlying surface from being damaged by the weather condition. It totally works like a shield and does not let the underneath surface attract rust, corrosion, or any stubborn dirt.

Epoxy primer is such a magical primer that you don’t even have to prepare the surface giving a vigorous effort. It just simply helps in attaining a decent finish that will be durable and perfect on any topcoats. Its thickness spreads all over the surface pretty evenly and that’s why most people choose this primer to paint their car and get an appealing result for that. Apart from the bare metal surfaces, this primer is also efficient in filling dents and crevices leaving a seamless effect on the surface.

Another best thing about epoxy primer is it is free of completely lead and zinc chromate. Though lead is a very toxic molecule and harmful to the environment, it adds some solid qualities to a primer. Nevertheless, the other components of epoxy primer work just as fine. One thing to remember is that epoxy primer does not work in neutralizing or abolishing rust rather it just helps in preventing the infestation of rust anymore.

Things We Liked about (Pros):

  • Provides the most genuine base for the paint on a metal surface
  • Comes with high pigmentation to resist rust, corrosion, and moisture to penetrate
  • Leaves a non-porous and even finish and protects the underneath surface as a shield
  • Offers robust protection on waterproof materials and saves them from oxidization

Things We Didn’t Like about (Cons):

  • To be cured properly and within less time it requires a catalyst

About Urethane Primer –

Urethane primer is as effective as any other high-quality primer but there are some different effects you will get when you use urethane primer. But you cannot just apply this primer directly anywhere you like. It requires some preparation before you apply urethane primer on a surface. Bare metal surfaces are just fine to get along with urethane primer but before that, you need to make the surface completely rust-free and free of metallic scales, and clean to get the utmost result in texture and finish.

If you want a smooth and reliable texture, then urethane primer will prove a hundred times better performance than any other primers out there. Besides this advantage, this primer has a great preventive ability also. Though this preventive quality is not as efficient as an epoxy primer, you can rely on urethane primer to some extent for sure. Thus you can use it to prevent rust and corrosion from the metal surface. However, you cannot expect a urethane primer to work as a sealer. It is basically a surface primer.

But you can certainly trust their 2K urethane primer for those purposes. It is a heavy-duty and high-build primer. Besides, it works as a filler primer and doesn’t even require sanding after curing. Because of this advantage of this primer many people also want to compare 2K urethane primer Vs epoxy primer Vs polyurethane primer. This polyurethane primer, having polymer in it, works on improving the bond and adhesion of the floor.

Basically, there is no major difference between urethane, 2K urethane, and polyurethane primers. They might slightly vary from one another but their application process and the finish point that you will get by using them are the same. Their textures are also the same and you can freely apply as much coating as you want. But in that case, sanding is required. Using urethane primer after a sealer brings more of an effective result. However, to get strong bondage and long-term effect you can apply an epoxy primer underneath the urethane primer.


  • Guarantees a nice and smooth texture after the primer is cured on the surface
  • Not only works on bare metals but also works on wood, plastic, ceramic, and other surfaces also
  • Prevents the metal surface from a further attack by rust and corrosion
  • Helps in providing the maximum color quality and offers a high-build shield to the surface


  • Cannot be used directly on rusted metal surfaces

Epoxy Vs Urethane Primer Differences & Comparison:

So far we learned a lot of important facts about both epoxy vs urethane primer. Individually both primers seem suitable and thus you might start to think that both provide almost the same quality. But it’s not the same and differs from various ranges. Once you get to know their dissimilarities properly, you will understand more about the better one. To get it, observe our following segments carefully.

Different Surfaces for Application –

Different Surfaces for Application

The first and important dissimilarity between epoxy primer and urethane primer is that they cannot be applied on the same surface. As a high-build primer, epoxy primer can be applied on solid metal surfaces without any preparations. It doesn’t bother with the old rust and corrosion lying on the surface of the metal.

On the other hand, urethane is a little bit sensitive in this way. It cannot be applied directly on any surface until it is prepared for it properly. You need to abolish the old rust and scales from the surface as much as possible before applying the primer. However, there are some specialized urethane primers that can be used on unprepared surfaces, so you can look for them as well.

Different Effects on Surface –

Different Effects on Surface

Another important difference is both primer put different effects on the surface. Epoxy primer, when applied on a surface, behaves like a basic primer. It strengthens the adhesion of the surface and prevents corrosion and rust more effectively than urethane. This primer is the most suitable one for sandblasted metal surfaces.

Conversely, urethane primer does not work as a base primer. It works more as filler and put great effect if applied after bodywork. As it works as a surface primer, you can comprehend the difference already. Epoxy can be used as a bridge or basic primer between the bodywork part and the urethane primer. Also, urethane is not as capable as epoxy in preventing rust and corrosion. Therefore, thinking these two primers can be interchangeable is foolishness on your part.

Sanding Process –

Sanding Process

As we have already mentioned that epoxy primer works as a base primer and remains underneath paint and bodywork, it does not require sanding. You can leave it without sanding and still meet the best adhesion and rust-preventive formula out of it.

Oppositely, urethane cries for sanding because, without it, the primer cannot give its level best. It is a crying need before you tend to apply a top coat over it. If you just sand the primer beforehand, the application of the topcoat will be more vivid and contoured.

The difference in Texture –

Different in Texture

The texture does matter whenever it comes to an application of primer. You cannot expect a smooth texture from an epoxy primer. As it carries components like zinc phosphate, they create the surface rough and the texture does not feel smooth.

But when we talk about urethane primer, we know how capable it is to provide a finely textured surface. The smooth feeling that this urethane primer provides is really praiseworthy. That’s why it is more suitable for the outward coating on a surface.

Different Workability –

Different Workability

Another significant difference is both primer work on different priorities, though they both are primers. Whereas epoxy primer stands out in providing the best adhesion quality, urethane primer stands out as a great filler for dents and gauges.

Then again, while the epoxy is used as the first coat, urethane is used after several coats of other substances. Therefore, we witness epoxy primer to protect metals from rust and urethane primer to assist in providing the best final finish of the whole work rather than preventing rust to attack. Read Also: Clear Coat Over Metallic Paint: 5 Ways to Enhance Beauty

Different Levels of Undercoats –

Different Levels of Undercoats

You can already assume that a primer is actually used as an undercoat so that the topcoats pop out and stick to the surface properly. However, if you are going to use both primer, to get the perfect result, you cannot just choose one and use it as the base coat. In a condition like that, you need to put epoxy primer first. And then you are allowed to use urethane primer over it.

Otherwise, the urethane will not work as a base primer and epoxy will not work as a surface primer. Thus, you’ll not get the right adhesive and effect from them eventually. Most people use both these primers to get optimal performance. They together provide immense rust-preventive power, increase adhesion, and provide a great finish to the surface.

So, Which Primer is Better?

It’s not that you must choose one from either an epoxy primer or urethane primer. Depending on the situation and condition of the surface, you need to choose one because both have individual powerful characteristics to impress. If you have a rusty yet sandblasted surface and don’t have time to prepare it and also want great adhesion for paint, then go with the epoxy primer. It works better as a basic primer and covers the rusty surface without bothering it.

On the other hand, if you want a smooth finish and want the bodywork of your car or vehicles to pop out with a nice texture, then urethane primer is your go-to product. Besides, it works as a great filler and so if you are ready to prepare your surface and want a non-porous texture after applying a primer, then choose urethane primer.



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<a href="https://finestsolve.com/epoxy-primer-vs-urethane-primer"><img class="aligncenter" title="Urethane Primer vs Epoxy Primer infographics by Finestsolve.com" src="https://finestsolve.com/wp-content/uploads/Epoxy-Primer-Vs-Urethane-Primer-infographics.png" alt="Urethane Primer vs Epoxy Primer infographics" width="800" height="2000" /></a>

FAQs –

Question-1. What is urethane primer used for?

Answer: Urethane is mostly used as a surface primer and is mostly used to promote adhesion to the surface. Besides, it comes with a rust-preventive formula to resist them to attack the surface and infest it. Also, this primer increases bondage between the surface and top coat if it is applied following the right process.

Question-2. What is stronger urethane or epoxy?

Answer: Both have strong effects but on different aspects. For example, urethane does not provide a strong rust-preventive formula like epoxy. It also cannot offer adhesion power similar to an epoxy primer. But that does not mean urethane is useless. Epoxy cannot provide as smooth a texture that urethane provides.

Besides, to fill gauges and dents, you can expect more from urethane than an epoxy primer. Therefore, their strength varies in different segments but both are worthy for sure.

Final Word:

Primers should be selected based on the type of application, the degree of traffic, and the environment. When it comes to selecting a primer, it is imperative to understand the unique needs of each project. We discussed our previous section about both Primer quality and its effects.

Primer types most commonly used are epoxy and urethane. However, they have different applications even though they serve the same purpose. When applying urethane primer, the surface should be primed before applying epoxy primer.

The epoxy primer works best on bare metal, while the urethane primer works best on bare wood. Be sure to check the site conditions to determine whether or not there will be movement of the system, as well as the manufacturer’s recommendations.

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