MTFCA Forum

I have a Campbell Hausfield spray gun and compressor. I have the spray gun set just right and an in-line glass bowl condensation remover. I shake the paint sufficiently and strain through a nylon stocking to remove impurities, but I am still getting the occasional fisheye. What is the cause of fisheyes and what is the secret to eliminating them. When painting, even one is too many. Jim Patrick

I have been repairing and painting cars since the early 1980’s
Contamination on the panel is probably the culprit.
Make sure to use a good wax and grease remover before painting and follow the directions.
If you are painting a solid color, you can use a touch up brush to use paint to fill it after it has cured. Then sand it flat with 1200-1500 grit paper and buff it.

Fisheyes are usually the result of silicone contamination on the surface of your part. Sherwin-Williams and Eastwood offer a fish eye eliminator as do other paint manufacturers. A tiny amount added to your reduced paint will go a long way to prevent them, but always wipe down your surface with either reducer or wax remover. ( and don't use anything like WD-40 near your spray area).

What are you using to wipe down? What type of compressor and lubricant for the pump? Any other cleaning or conditioners used in the area?

Pat Branigan Wisc wrote: ↑

Thu Dec 14, 2023 3:12 pm

What are you using to wipe down? What type of compressor and lubricant for the pump? Any other cleaning or conditioners used in the area?

Exactly. Anything at all containing silicones especially!

The Dodge truck plant in Warren, MI had a big problem with silicone contamination some years ago. It turned out, the cleaning crew would come in at night to clean the front offices. The front lobby had a very nice plastic fern of some sort. The cleaners would spray it down with a furniture polish to make it look bright and shiny. The silicone in the polish got into the air handlers and circulated silicone particles into the paint area, where it ruined countless paint jobs. It took many thousands of dollars to completely decontaminate the entire air duct system in the offices and plant.

I always use wax and grease remover until it’s perfectly clean, tack cloth and I spray a tack coat. I don’t paint a lot but it seems like most issues are caused by poor surface prep.

If you are doing a base coat/clear coat finish, not allowing enough dry time for the base coat before doing the clear coat, can cause what is called pigment popping, where the base coat solvents come up thought the clear. They look just like fisheyes, but a totally different cause. Fisheye remover makes it worse not better!

Any kind of oil or grease can cause it.
At a plant where I was Plant Engineer, we had a problem with fisheyes that gave us fits.
Only happened after lunch on a certain day. Turned out it was from one painter that would have barbecue from home for lunch.
Ran us crazy.
Another plant that was customer of mine was caused by a maintenance man sealed an air duct on other end of plant from paint with silicone sealer.
When I ran a expat and powder plant I would not even let silicone in the plant.

I have a small “Husky” compressor and wipe down everything with Lacquer Thinner. My water remover is connected to a 100’ hose. I once read that a long hose is needed to allow the the heated compressed air to cool and convert the water condensation to liquid water that is captured in the glass reservoir which is secured and always pointed downward. If the hose is two short, the condensation will shoot right through the water remover. There are no silicone products around the area that I know of. Jim Patrick

A mate in Spokane had a similar problem, even though anything with silicone was banned from the shop. He kept getting fisheyes on an A model he was painting. Assiduous attention to detail when the owner was rubbing down between coats made it no better. Turned out to be silicone in the hand cleaner he used when he got home at night, traces of which remained next morning when he started rubbing again.

Allan down under.

yes! base coat /clear coat and fisheye eliminator is a no no. It is only for use with single stage top coats.

Silicone and oil contaminations can come from many places as attested to by Dan and below.

I had a customer on the Eastern Shore of Virginia that developed fisheye issues. Turned out that the Royal Farms recently built across the road from his shop, cooks fried chicken and the exhaust system would vent oils into the air and it would settle on his cabinet work due to his close proximity to the gas station.

If you choose to use fisheye eliminator, there will be a significant chance that you will have to continue to use it on future work. It most likely will contaminate your spray gun.
They type we sold was silicone and when dispersed into a coating, acts like a surfactant, modifying the surface tension in the coating, creating one big fisheye vs the little ones.

Also I would call Bill D's description as solvent pop vs pigment pop. Had lots of fun modifying coatings to work with Air Assisted Airless spray equipment since pressure and not air atomize the finish. the film build retained more solvent and under pressure it liked to bubble just like opening a carbonated beverage, retarding dry time was the most frequent correction for solvent pop, followed by reduction in air movement to give the solvents a chance to disperse before the film skinned over.

jiminbartow wrote: ↑

Thu Dec 14, 2023 2:17 pm

I strain through a nylon stocking to remove impurities

Very likely the problem! Don’t do that! Your automotive paint store will give you a pile of proper strainers for free when you buy your paint & primer.

I have always used single pack lacquer on my T's. It is very forgiving, easy to touch up, and gives what I consider a more period correct finish, as opposed to plastic looking ultra shiny two packs. I too strain through nylon stockings, with never a problem. The good thing is they stretch over the can, so that when decanting paint into the gun pot, the lumps never leave the can.

Allan from down under.

Is there any chance your compressor is passing a bit of oil into the air?

A friend of mine terrible probelms with fisheyes. It turned out, the brand new hardener he just bought was contaminated.

Allan wrote: ↑

Fri Dec 15, 2023 7:24 am

I too strain through nylon stockings, with never a problem. The good thing is they stretch over the can, so that when decanting paint into the gun pot, the lumps never leave the can.

Allan from down under.

That speaks for itself… Lumps in the can? Egad!

When using enamels, it is not unusual to break into a 1 gallon can more than a few times, especially when painting T parts black. Towards the bottom of the can, the paint does skin over. It is the repeated skin removal which can result on lumps in the remaining paint. These are easily contained in the can and the paint for use poured off through the nylon stocking. Much better than discarding unused portions of remaining paint. The lumps are usually discarded with the used bit of stocking.

Allan from down under

Fish eyes come from any oily impurities, especially the presence of silicone. It is always better to shake the paint each time and not rely on stirring only, to ensure mixing of the heavy pigments for assured color match. Enamels are prone to "skinning" over. I learned in my apprenticeship that after application, enamels dry from the bottom up and lacquers dry from the top down. Also, as you remove paint from the can, it is better to reduce the can size to eliminate air volume in the can. Jerry has a point worth noting. An air separator is mandatory.