Best Epoxy Primers: Give Your Car Extra Protection

Give your car a new look—and a new lease of life—with these top epoxy primers

byAlice Musyoka|
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BYAlice Musyoka/ LAST UPDATED ON May 7, 2021

Epoxy primers are a common sight in auto shops. They are used as a final sealant after a paint job. They also serve as a starter coat for steel. For many car owners, getting a top-shelf epoxy primer is an uphill climb because there are so many options to choose from. But after you read this buying guide, it should be easier for you to find the best epoxy primer for your needs.

Best Overall
Speedokote 2-in-1 Primer

Speedokote 2-in-1 Primer

This two-in-one primer offers great adhesion and does not affect the quality or final look of any paint job.
You can use it to seal paint or use it as an initial coat before paint application. The primer can be used on a range of surfaces and delivers remarkable results. It retains its quality even when it’s not used for a long time.
It may be too thick for some users. It also has a high price point compared to other epoxy primers.
Best Value

SprayMax 2K Activated EPOXY Primer

This black epoxy primer has excellent anti-corrosion and  adhesion properties. The aerosol spray comes ready to use, all you need to do is shake it beforehand.
It can be used on anodized aluminum, cold-rolled steel, hot-rolled steel, zinc-coated steel, fiberglass, and other materials. It has a wider spray pattern than traditional aerosols. Once it cures, it becomes very hard and lasts for a long time.
It’s not more durable than a 1k primer and its spray pattern is very wide. The can’s pressure is also not very high.
Honorable Mention

Custom Shop Black Epoxy Primer/Sealer

The kit includes one container of epoxy primer and one container of epoxy hardener. The one-to-one mixing ratio allows for precise mixing.
The primer is specially designed to be used directly on metal. It has an advanced resin technology and offers superior adhesion to a variety of materials, including steel, fiberglass, bare aluminum, and rigid plastic. It is devoid of lead and chromate and provides maximum protection against corrosion, rust, and salt spray.
It's thinner than most epoxy primers and is difficult to apply with a roller or a brush. The clear activator may contain tiny pieces that don't dissolve.

Benefits of Epoxy Primer

  • Sealing up bare metal. An epoxy primer is very effective at sealing up bare metal and prevents moisture or corrosion from creeping in. It keeps out oxygen, ensuring that rust or corrosion do not form on the surface. It is non-porous when it cures and does not soak up moisture like most primer sealers.
  • Can be used on a variety of materials. Because of its strong adhesion, chemical resistance in high-humidity environments, and good mechanical ability, epoxy primer can be used on a variety of materials. It can be applied on steel, galvanized steel, aluminum, fiberglass, wood, asphalt, and concrete.
  • Prevents rust and corrosion. The main job of epoxy primer is to protect materials against rust and corrosion. A two-part epoxy primer contains zinc phosphate, something that enhances its corrosion-inhibiting properties. While paint is filled with pigment, primer is filled with binding elements that ensure no oxygen gets in to trigger corrosion. Epoxy primer can be used to waterproof materials and to protect bare metal from oxidation.

Types of Epoxy Primer

One-Part Epoxy Primer

One-part epoxy primer consists of a sealer that creates a smooth finish when applied on top coats. The sealer creates a non-porous finish and is usually the first base coat applied to bare steel. Epoxy primer can also be applied over black iron, phosphate coating, fiberglass, and plastic. Epoxy primer works best on bare metal and is recommended for newly-fabricated metal parts or those that have been fully stripped. You can also apply primer surfacer or filler over epoxy primer to get rid of any minor imperfections and to create a flat surface before you paint. It is used as a final sealant prior to painting and also functions as a starter coat for steel.

Two-Part Epoxy Primer

This is a two-component primer which contains a sealer and zinc phosphate. The zinc phosphate is added because of its corrosion-inhibiting properties. A two-part epoxy primer is a structural steel primer. Its two components cure chemically by cross-linking. After curing, the resulting film is resistant to moisture, chemical, and abrasion. Two-part epoxy primers are mostly used on steel and concrete and industrial applications like tank exteriors, water treatment plants, marine equipment, and power plants.

Top Brands


This company was established by a team of experts who researched the refinish market to determine the best and quickest techniques for mobile refinish repair. Most of its products are developed after consultations with mobile refinish technicians and significantly reduce the repair time. The company is based in Dayton, Ohio, and manufactures coatings and speciality products that consist of VOC-compliant materials. All of its products, including the popular Speedokote Fast-Dry Low-VOC DTM Epoxy Primer & Sealer, are manufactured in the USA.


The story behind this company is a simple but interesting one. The owners simply wanted better products for their own boats because even the popular products had room for improvement. After TotalBoat was launched, it started developing marine repair and maintenance products. The company makes a host of products, from epoxy primer to varnish. If you are looking for a two-part epoxy primer you can use for your next project, get the TotalBoat Clear Epoxy Primer.


This company was established in 1921 by Robert Ferguson, who was a sea captain. Ferguson had noticed that fish oil that had spilled on rusted metal decks prevented corrosion from spreading. The initial formula contained whale oil but many changes have been made throughout the years to make the product better. The company is based in Vernon Hills, Illinois, and now manufactures protective paints and coatings for residential and commercial use. We particularly love the Rust-Oleum 247597 VK9300 Epoxy Spray Primer.

Epoxy Primer Pricing

  • $10-$50: Most of the epoxy primers in this category use an aerosol spray dispensing system. They are usually small in size and may be sold together with sealers.
  • $50-$100: The epoxy primers you’ll find in this category may be part of a kit or of higher quality. Some are sold by popular brands like Raptor, Interlux, Speedokote, and Rust-Oleum.

Key Features

Corrosion Resistance

An epoxy primer has one main job: to offer protection against rust and corrosion. It goes without saying that this is the first feature you should look for. Make sure the epoxy primer you choose is highly resistant to corrosion, deterioration, and damage. And if you live in an area with a lot of humidity, make sure the product has the ability to block moisture.


This is another important thing you must take into consideration. Choose an epoxy primer that is suitable for the material you will apply it on. As we had mentioned earlier, one-part epoxy primer can be applied on a wide range of materials (including plastic), while two-part primer is mostly used in industrial applications. Choose the epoxy primer based on the material or you will be disappointed because it won't adhere. 

Volatile Organic Compounds (VOCs)

Volatile organic compounds are present in many building materials. They are usually to blame for the new paint smell. However, they emit dangerous gases into the environment that affect people's health. This is the main reason why the government now regulates them. Choose an epoxy primer with reduced amounts of VOCs (indicated as low VOC) or none at all (indicated as 0 percent VOC).

Other Considerations

  • Curing Time. The curing time of an epoxy primer is very important. The product does not like humidity and takes longer to cure in environments with a high level of humidity. Generally, it takes between two and five days for epoxy primer to fully cure. If you live in an area with a temperature of 55 degrees Fahrenheit and below, epoxy primer may take longer to cure. If it is tacky to the touch, know that it hasn't dried. You can use electric heaters or heat lamps to cure it.
  • Ease of Use. Applying an epoxy primer should not take the whole day, so choose a product that is easy to use. It is worth noting that some epoxy primers need to be mixed with other products before use, while others do not. If you get an aerosol spray, you only need to shake it well before use. You should also get a product that does not require a lot of preparation beforehand.

Best Epoxy Primer Reviews & Recommendations 2021

An epoxy primer is a resin-based sealer that forms a non-porous surface once it cures. And although the surface is very hard, you can sand it with a sanding machine to create a very smooth surface that's easy to paint. This high-build urethane primer creates a thick layer and you can thin it with a thinner of your choice.

This epoxy primer is specially designed for the mobile repair industry. You will love the fact that it dries and cures very fast without compromising substrate adhesion. After it cures, it is easy to sand and leaves a smooth featheredge (an edge that thins out like a feather). If you want great results, follow the instructions provided by the manufacturer. And don't forget to sand the material as soon as the primer cures, as it hardens very quickly.

While this is one of the best primers on the market, it has a few downsides. It is more expensive than similar epoxy primers on the market. You may also not be too pleased with the thick layer it creates. And if you let it cure for too long, you may have a very hard time sanding it.

There's no use buying an epoxy primer that does not work. It must be easy to apply, cure well, and leave a smooth finish. It must also be long lasting. Not every epoxy primer on the market has these features, but the SprayMax 2K Activated Epoxy Primer does. It comes in an aerosol can for easy application. It is the perfect product to use on bare metals because it offers excellent adhesion. It also forms a protective coat to protect metals against corrosion.

If you are in the market for an epoxy primer that does not need to be mixed with a sealer or another product for the best results, this is it. SprayMax has designed the can in such a way that it has a broader spray pattern than traditional aerosols. And thanks to its wide spray pattern, you may complete your project sooner than you expected. You can use the epoxy primer on a variety of surfaces, including fiberglass, anodized aluminum, cold-rolled steel, hot-rolled steel, and zinc-coated steel.

However, the product is not without shortcomings. For starters, some users have complained about it not being more durable than a conventional 1K primer. The pressure inside the can is also not very high, so the amount dispensed may not be sufficient. And since the spray pattern is very wide, the film may be quite thin.

Custom Shop sells its epoxy primer/sealer separately from its hardener. The good thing is that they both come in two large containers. The primer quickly primes the surface and the hardener makes the coat tough and durable. This is a very strong adhesive that can be applied on different surfaces, like bare metal, aluminum, steel, gelcoat, and fiberglass. It's a DTM (Direct to Metal) Primer.

The 1:1 mixing ratio makes for more precise mixing. The mixture is easy to apply and once it cures can be easily sanded. There is no induction time required before application. The primer is free of lead and chromate and features anti-corrosive properties to offer maximum defense against rust and corrosion. It is also resistant to salt spray and dries and very quickly after application.

The great thing about this epoxy primer is that it can be used as a sealer for basecoat clear coat. It is available in black, white, and gray colors with differently-sized quart kits and gallon kits.

However, it is much thinner than most epoxy primers and you may have difficulty applying it with a brush or a roller. Additionally, the clear activator has tiny pieces that may not dissolve at times.

This product makes your job easier because it functions as a primer and a sealer. Its mixing ratio is 4:1. You can also get it together with a VOC reducer to decrease the quantity of volatile organic compounds. The primer can be used on a wide range of materials, including fiberglass, steel, and aluminum. It is also easy to apply and leaves an even finish for a professional look.

This highly versatile epoxy primer is suitable for a variety of priming needs. It dries quickly and offers protection against rust, corrosion, and deterioration. In an environment of 75 degrees Fahrenheit, it only takes 15 minutes to fully dry. This means you will be done with your project in no time. Whether you want to prime metal surfaces or prepare your car for a paint job, this primer is an excellent choice.

It has been tried and tested by both professionals and DIYers, so you can buy it with confidence. It offers long-lasting protection against corrosion and will protect your surfaces for a long time to come. 

However, it is worth noting that some people find it too thick for their liking. Because it doesn’t come in an aerosol can, you have to use a squeegee to spread it, which may be an inconvenience.

Picking the best epoxy primer may seem very straightforward, but it isn't. You have to weigh all your options before making a purchase. One of the things most professionals consider when buying an epoxy primer is how much preparation is needed. Some epoxy primers can be applied immediately while others must be mixed with other components before application. If you are not willing to put in extra effort to prepare the mixture beforehand, get this epoxy primer.

It is a corrosion-resistant primer that is free of lead and chromate. We also love that it provides excellent adhesion to a variety of materials. It resists damage caused by water permeation and improves the adhesion of body fillers. You can use a thinner to reduce its viscosity. When the viscosity is reduced, you can use it as a sealer, a ground coat, or a precoat before applying the top coat.

However, for the best results, you can’t use this primer on its own. You have to buy the Transtar 6144 activator and mix the two products at a ratio of 1:1. And if you want to use it as a sealer, you have to get the Transtar 6700 Urethane Grade Reducer.

If you want to prime a large surface, it is important to get a primer that can do the job excellently in the shortest time possible. What we like about this primer is that it is of high quality and makes any surface smooth after application. It allows paint to stick more easily for a shinier effect.

The primer is designed to be used on yachts and protects metals from rust and corrosion, whether they are above or below the waterline. Microsheet silicate technology allows it to build a powerful water barrier that resists moisture and water penetration. But to get a usable product, you have to mix the epoxy primer with the hardener.


The product is sold as a 2-gallon kit or a ½-gallon kit. You can get the latter if you only want to tackle small DIY projects. The epoxy primer is highly resistant to humidity and high temperatures. After it cures, you can apply several coats of paint on top of it and the finish will be very smooth. However, the manufacturer recommends that you don't apply more than four coats of paint on top of it.

You can apply this epoxy primer over blistered fiberglass as a repair coat. It is a high build epoxy, which means you only need to apply a few coats for great results.

However, while it is a great product, it doesn't come cheap and costs more than similar primers. It also takes two days to dry, which is long compared to some epoxy primers.

This two-part epoxy primer can be applied on fiberglass, gelcoat, sandblasted surfaces, rough concrete, and rough plaster. Its heavy viscosity allows it to fill imperfections on surfaces for a more uniform look. In the Swim has designed this top-of-the-line epoxy primer for swimming pools. It creates a solid base coat for swimming pool paint and quickly absorbs surface moisture.

The best thing about this epoxy primer is that it can be applied even when the surface is damp. For the best results, use a paint roller to apply it. A gallon is enough to cover up to 150 square feet. The primer has a pot life of four hours in a setting with a temperature of 85 degrees Fahrenheit. Before applying the top coat, leave it to cure for 24 to 48 hours.

While we love this epoxy primer, we feel In the Swim should make the container more tough because it gets easily dented. The primer also dries very quickly, almost too quickly. One end of your swimming pool may be dry by the time you get to the other end.

The Eastwood AeroSpray Epoxy Primer makes your priming jobs easier than ever. It is an incredible adhesive that does not need to be spread using a squeegee. All you need to do to activate the product is give it a quick shake. The aerosol spray allows you to work with a lot of precision without using a paint gun. It is designed using Eastwood's patented technology and provides a long-lasting finish, keeping your material beautiful for years to come.

The aerosol can features nozzle and valve technology and two internal chambers that make sure the product is mixed in the right ratio every time. The nozzle sprays the primer like a paint gun and has a wider spray pattern than traditional aerosoles. This epoxy primer can be applied on fiberglass, steel, aluminum, existing finishes, and body fillers. The pot life is approximately 48 hours after the can is activated.

The Eastwood AeroSpray Epoxy Primer is a good choice if you're looking for a primer that is easy to apply and also durable. It dries at top speed and will ensure you complete your priming jobs without sacrificing quality for speed.

However, the aerosol can has a tendency to leak. And since it comes in a small size, it may not be enough for your project.


  • The best epoxy primer can be applied to different surfaces. Make sure the primer you choose can be used on a variety of materials, including wood, steel, fiberglass, and even plastic. 
  • If you are using a thick primer, ensure your spray gun has the right nozzle to deliver a uniform finish. It is also vital to check if the product is meant to be spray- or brush-painted. 
  • Practice general safety every time you use epoxy primers as some are made of harsh chemicals. Wear protective gloves and masks to reduce your exposure to toxic fumes. 


Q: Can I use epoxy primer on bare metal?

A: Most primers can be used on bare metal. However, if you are unsure about the product, read the manual to learn about its effectiveness. 

Q: Can I use epoxy primer on a bed liner?

A: Yes, epoxy primer can be used on truck bed liners. Choose one that withstands extreme impact, is resistant to automotive chemicals, and adheres well to most truck surfaces.

Q: Which is the best air spray gun tip to use?

A: A 1.8mm tip is a good choice. Generally, thick primers work best with a 1.7mm to 2.2mm tip, while base coats work well with a 1.4mm to 1.6mm tip.

Final Thoughts

For a glossy finish and easy application, we recommend the Speedokote 2-in-1 Primer

However, if you are looking for something that can work in different environments, the budget-friendly SprayMax 2K Activated EPOXY Primer is a must-have.

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