Epoxy primer serves a wide range of automotive needs, providing quality resistance to corrosion, fast build, exceptional color holdout and strong adhesion to bare metal substrates. This direct-to-metal primer is specifically ideal for use after sanding or media blasting projects due to its filling qualities. It’s also a good primer for brand new metal.
In this guide, we take a look at how to properly apply an epoxy primer to the body of your vehicle. You can apply high-build epoxy using standard high volume low pressure (HVLP) paint equipment. By laying a good foundation, your basecoat and topcoat will have long-lasting beauty.
Supplies and Tools You’ll Need
- Eastwood epoxy primer and catalyst with mixing tools.
- HVLP paint gun, conventional gravity gun or siphon gun (see below for spray tip sizes and pressures).
- Shop air compressor.
- Eastwood PRE® Painting Prep wax and grease remover (plus cleaning cloths).
- Sanding tools to remove any rust, corrosion or pre-existing finish.
- Eastwood Contour SCT® surface conditioning tool.
- Masking tape and paper.
- Protective goggles, face mask and gloves.
Step #1: Surface Preparation
First, if you are using epoxy primer on bare metal surfaces, it is important that all existing paint and corrosion are properly blasted or stripped off. To prepare a bare metal surface for this primer, clean and degrease the surface with Eastwood Pre Painting Prep which is also available in a 50 State Compliant version called Pre Green Paint Prep. This will ensure that all road grime, dirt, grease and other surface contaminants are removed. If you are only priming part of a vehicle, use your masking tape and paper to block off the areas around where you’ll be priming to protect them from overspray.
It is important that the metal surface is slightly abrasive so that the primer coat will be more adhesive. When you are applying epoxy primer over already existing finishes, use these same steps above, and make sure to abrade the surface with 320 to 400 grit sandpaper or your Eastwood Contour SCT metal conditioning tool. Rougher sandpaper grits and finishing wheels can be used to remove any surface rust or corrosion. Always be sure to clean the metal surface with the wax and grease remover again after abrading it.
To prepare the epoxy primer, shake or stir the primer following the instructions on the label, then thoroughly mix one part primer with one part catalyst. To reduce any film buildup, this one-to-one ratio can also be cut with a urethane-grade reducer or comparable solvent solution. This can also improve the overall flow of the primer mix. Be aware that epoxy primer can begin to gel after only 90 minutes in a 70-degree environment.
You can use an HVLP spray gun, conventional gravity gun or conventional siphon to coat epoxy primer.
The Eastwood Elite P500 is a great option for applying primers. Here are the guidelines for each method:
- If you are using an HVLP spray gun, make sure the fluid tip is between 1.4 and 1.8 mm and the spray pressure is between 25 and 30 PSI.
- If you are using a l gravity gun, make sure the fluid tip is between 1.4 and 1.6 mm and the spray pressure is between 45 and 55 PSI.
- If you are using a conventional siphon, make sure the fluid tip is between 1.6 and 1.8 mm and the spray pressure is between 45 and 55 PSI.
Once you have the spray gun and primer mix prepared, it is time to apply it to your metal surface.
Step #2: Primer Application
The Eastwood Epoxy Primer should be applied in medium wet coats, allowing a half-hour between each coat at around 70 degrees. One to two coats will render a 1-mm dry film thickness, which is typically enough to be completely effective. Make sure to evenly spray each coat completely across the bare metal surface. If your spray gun is spraying unevenly, it needs to be properly cleaned.
Epoxy primer can be top-coated after about 30 minutes (45 minutes to an hour if more than two coats were applied), or even up to five days after the last coat. If you are waiting more than a couple days, the surface should be lightly sanded again prior to topcoat application. Once you’ve applied all the coats, the surface can be wet sanded after a single day, but it is best to wait two to three days before dry sanding.
As always, make sure you are wearing the proper safety equipment (goggles/face mask and gloves) while performing this task. Also, be sure to seal each of your solution containers and properly clean your spray gun immediately after each use. That way, your equipment will be ready to use the next time you need to apply an epoxy primer.
Other Epoxy Primer Solutions
To learn more about epoxy primer and for more DIY car tutorials be sure to visit Eastwood.com. We have several other epoxy primer solutions to fit your needs and budget, including 2K AeroSpray® Epoxy Primer Spray Finish and the revolutionary Eastwood OptiFlow Roll-On Primer System. If you’re looking for visual assistance and other expert tips, watch our How to Spray Epoxy Primer with Kevin Tetz video tutorial. We’ve been helping DIYers Do the Job Right since 1978.
To learn more about epoxy primer and for more DIY car tutorials, be sure to visit Eastwood.com.