What Causes A Fisheye In Paint?

There aren’t many things more heartbreaking to an automotive painter than preparing an item for paint and taking all the necessary steps to clean, prep and spray your project only for a paint issue to come up after the paint has laid or dried. Like most problems in the world, you can potentially solve or prevent them if you educate yourself to what causes the problem.

One of the most common paint defects is what’s known as the fisheye. Below, we cover some potential causes of fisheyes in paint, precautions you can take to prevent them and options for how to fix paint fisheyes so your vehicle is unblemished.

What Is a Paint Fisheye?

Paint “fisheyes” show themselves as small round or circular-shaped defects that can have a tiny crater in the center. They typically appear as white dots with circles of paint or separation surrounding them. They look a lot like real fisheyes, hence the name. Other names for this defect include craters, saucering and pits. Fisheyes tend to show themselves as you apply a coating on the surface or immediately after the surface has been coated.

Why Do Paint Fisheyes Happen?

A fisheye is caused by a contaminant either on the surface of your paint project or in your equipment. The cause could be many things, but usually it is one of the following:

  • Water
  • Chemicals
  • Oil
  • Silicone-based substances

If any of those have attached to the surface or gotten into your paint gun, you may have a fisheye issue.

How Do I Prevent Paint Fisheyes?

The best way to stop fisheyes in paint is to own and maintain proper painting equipment. One thing to consider is your air filtration system. Do you have a good separator and air filter on your compressor? If not, you should strongly consider adding one. Regular air compressor maintenance, such as draining condensation, cleaning the intake valves and changing the air filter, is also a good way to prevent contaminants. (Read our article about How to Reduce Moisture in Compressed Air Systems for more information.)

Take a look at your HVLP paint gun too. Was your gun cleaned between coats? Failing to clean it properly greatly increases the chance of fisheyes. We suggest using a last-chance inline air filter before your paint gun to catch any contaminants in the airlines.

Another cause for fisheyes is a silicone-based substance getting in to the metal or onto the surface. This could be something as simple as someone across the shop using a spray detailer or cleaner on something, or possibly a splash of oil from an air tool getting on the metal and not being cleaned off. We always suggest using a proper paint prep solvent, such as Eastwood PRE Paint Prep, before priming and painting to clean and dissolve impurities off the surface.

How Do I Repair a Fisheye in My Paint Job?

Now that we know that a fisheye is caused by a contaminant on the surface, we need to remove whatever that is. If you just sprayed your coating on and it hasn’t cured, you can usually use a solvent to wipe the coating off, then clean the area and start over. For fisheyes that appear in a basecoat, after the color flashes, spray a mist coat over the area.

If the coating has dried or cured, you will need to remove the paint or clear in that area and sand to a smooth finish below the fisheye. We then suggest scrubbing the area well with a scuff pad and Eastwood PRE Paint Prep to properly clean the surface. You can then wipe the area clean and let the PRE flash off. Just before painting, go over the area with a tack rag to remove any dirt on the surface and get ready to spray. Make sure no other chemicals have been sprayed around the vehicle after cleaning.

If this is your top coat, you can also mix a fisheye eliminator into your coating to help reduce the chances of additional fisheyes. However, you should not add this substance to a basecoat or undercoating. If you spray over any area that contains a fisheye eliminator additive, you actually increase the risk of causing new fisheyes. For more automotive painting tips, visit the Eastwood How-To Center or call us at 1-800-343-9353.

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