Fish eyes after multiple degreasing attempts

[tabascom16]

My brake booster brackets and small parts are still getting really bad fish eyeing after at least 10 attempts to degrease with acetone. Anyone know what to do to get rid of the oils? I have thought about soaking it in a bucket of gasoline for a while and then degrease it a few times again and attempt to paint.

 

[broncodriver99]

Try brake cleaner. I thought fish eyes were a moisture problem.

 

[TN1776]

Try brake cleaner. I thought fish eyes were a moisture problem.

X2 moisture in the air lines that supply the spray gun was my first thought.

What are you using to spray the paint with?
If it is a problem with grease/oil on the part, you might try using some prep solvent like what you get at an autobody paint supply store.

 

[tmbuehrer]

Could be oil wax or water depending your paint. Should use a wax and grease remover before painting anything. Brake cleaner just isn't enough. After that should use a tack cloth to remove dust/towel debris.

 

[mjramacher]

If your using a spray gun use a moisture filter ball at the gun and get some fish remover at a local paint supplier if using a rattle can wax and grease remover is a must for both options.

 

[Broncofan76]

I encountered something similar. I degreased like crazy with wax and grease remover, wiped clean before it dried etc etc. I called my friend who's a long time painter and he advised me that sometimes there is just "dirty metal". after research i found this to be true. He said to coat it with several very light coats and eventually the fish eyes would get covered up. It worked for me. The specific parts that this occurred with were the mounting brackets for the procar seats.
good luck

 

[allenfahey]

As stated fisheyes are caused by contamination on the surface. They can also show up when you try to paint when it's too cold and apply too wet. It can also be contamination from the compressor in the form of oil, diesel fumes near the compressor, old air hoses which might have been hooked to an automatic oiler at the compressor, oil from other tools in the air fittings, or water in the line.

I assume you have the parts in bare metal and you are trying to put on primer or sealer? I will bet since they are parts in the engine compartment you didn't clean them enough prior to getting them in bare metal. If you have grease and/or wax on paint or a coating of any kind and you don't clean thoroughly prior to sanding you sand those oils and wax into the metal.
The best way to fix it is to use Dawn soap and wash, rinse well and dry to prevent flash rust. Then saturate the surface with a rag of thinner. Use another rag and wipe it till it's 100% dry. I suggest you do that at least twice. I would then use a wax and grease remover (also known as degreaser) from your local autobody distributor. After you tack it off put on a VERY light dust coat of primer or sealer. When I say light you should back the gun off the surface and use a light trigger. I f done right you should be able to see droplets on the surface and see thru it. Let that flash and put on another slightly wetter coat, let flash and then put on a few much wetter coats. If you do that you will be fine but if the compressor and lines are the cause of the fisheyes then you must fix that and do the above steps.

 

[joshnjulie1]

VERY VERY LIGHT COATS....OVER AND OVER AGAIN.

This will take patience on your part ( I know, I don't have any)

 

[73azbronco]

Silicone brake fluid? Second major reason for fish eyes is silicone, I'm not sure how to get that off.

Beyond that, more heat, self etching primer of very light coat, then paint of very light coat.

 

[Firedog67]

I like carb cleaner better than brake cleaner. Doesnt leave film and takes aways almost everything. Just my experience and opinion

 

[Unaweep]

Don't forget, metal is porous and will hold oil and contaminants, especially aluminum. Think of aluminum as almost spongy if its soaked with oils or transmission fluids.

J.E.

 

[pcf_mark]

I use a soap based cleaner first then wax/grease remover with a clean towel to apply and a separate clean towel to wipe dry. Also in line drier if using a paint gun / compressor.

Allan's technique for light coats is key if you have the skill and can put it on so light..not ME!

 

[lowbush]

Use tough stuff (can get it at home depot) or another airplane paint stripper it will remove everything including grease, silicone, wax or water contaminants (the stuff will even remove powdercoating), rinse with water to neutralize and then paint with light coats. If that does not work then just build up the paint with the fish eyes in it, then sand it like you would to remove orange peal, don't take it back down to the metal just sand it enough to smooth it out and then shoot it with a final coat. In my experience fish eyes are usually caused by moisture in oil or epoxy based paints. The water tries to separate and forms a drop in the liquid oil paint, which causes the cratered rim.

 

[Joker11]

As a welder, we use an oven to cook aluminum parts to get as much grease and oil out as possible.
On steel, I use a rosebud torch and hit trouble spots. That may work for you if everything else fails.

 

[Tedster100]

I had a similar problem when I painted the bottom of my hood. I did it in my shop just to see how the paint looked and so I could bolt it on for final paint in the booth. Cleaned with Acetone and sprayed, fisheyes everwhere. Used reducer and removed the paint and prepped again, same result. Then it hit me, I was using an old washcloth for a rag. I think it must have been the dryer sheet that left some sort of residue on the washcloth. Switched to a different rag and everything went down perfect. Sometimes it's not the obvious.

 

[bosshoff]

Would boiling the part on the stove with some Dawn do the trick without breaking down the part? I have used Dawn in the slow cooker with parts to some success. Not about using paint, though.

 

[Pa PITT]

... When I so all that DuPont paint .. The painter at the Cheby house . He used to wash & wash .. Then HE'D Clean with a lot or Spray-a-Way glass cleaner.. I say Gasoline will just add more problems.
.. I had a product called Prep-Sol .... AND THEN we sold these little capsules 222S I think .. But one of the other paint company's had a better product than I had .. Seems like it was called 707 or 7007 Metal Prep.
... If your part your painting has been close to Armor All .. It's a bitch.