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
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BY Alice Musyoka / LAST UPDATED ON October 10, 2019
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.
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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.
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.
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).
- 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
- 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.
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.