In the past self etching primer was the go-to coating to apply over bare metal on a car. Metal required little prep work to apply it, it flashes/drys quickly, and it came in 1K Aerosol cans for small jobs. In the past 5-10 years you’ve probably been hearing more people talk about Epoxy Primers and their use as opposed to self etching primer. We decided to give you some insight on where and when epoxy primer works best.
1. Over Bare, Clean Metal- Epoxy Primers are amazing at sealing up bare metal and from allowing moisture or corrosion to creep in. Epoxy primer actually seals out the oxygen from the metal leaving no chance of rust or corrosion forming on the surface like some cheap spray bomb type primers. Etch Primer included, Epoxy Primer is about the only primer you could lead a vehicle outside in without rust forming back under the primer quickly!
2. Mixed Surfaces- Some primers and coatings need the entire surface to be uniform and all the same material. Epoxy Primers have excellent adhesion properties and will stick to bare metal, paints, primers, and fillers. This means you can hit an area with epoxy primer that’s been sanded down to bare metal, repaired with body filler, and then feathered into the original paint. We suggest blending these areas as good as possible before spraying epoxy primers as they doesn’t have filling/build qualities like a high build primer and won’t hide imperfections as well. You can alternatively apply filler or primer surfacer over the epoxy to fill any minor imperfections and block flat.
3. Stacking Coatings- Since Epoxy Primers adhere mechanically, they will grab onto most anything that has a good texture to the surface. For this reason it works well for stacking if you need to correct an area that you didn’t get perfectly flat and need a little more filler. Just abrade with sandpaper, apply your filler, sand flat, and feather the edges. Then you can apply more epoxy primer over top. This can’t be said for many primers!
4. Use it for a final sealer- A cool trick we’ve been doing for the past few years is using our epoxy primer as a final sealer before our base coat. Simply reduce it 50% and lay a coat or two down to seal up all of your work and have a nice surface to lay your base coat over top of. This is a great peace of mind for a lasting paint job.
5. Use it to protect a long-term project- Not all of us have huge, climate controlled shops our project vehicles can sit in until they’re painted. This means you may have to push the project outside overnight or while you do maintenance on the daily driver. Maybe you have a damp shop that flash rusts metal as soon as the temps change? I like to use epoxy primer to seal my work at the end of the day. This way if I can’t get back to it right away I won’t come back to a surface rusted mess! Keep a handful of our 2K Aerospray Epoxy Primer Aerosols on hand for sealing up small areas. They will save you time in getting out the spray gun, mixing up primer, and then having to clean everything back up!