Dealing with Fisheye

A finisher finds the source of his fisheye problem (silicon overspray from an auto detailer next door) and the solution (cleaning contaminated surfaces with ammonia). October 26, 2005

I've made two posts concerning a fisheye problem and I think I have found the source. I thought it was oil in my compressor system because I had just changed the oil before the problem appeared. I cleaned out the system and bought a new second filter for the line and the problem went away – until today. I was spraying this morning and having fantastic results. I left for lunch, and when I came back I picked up the next door to spray and noted a large amount of fisheye. I thought maybe I had grease on my hands from my grinder, so I washed them and sprayed a test piece and got fisheye in the results. I noticed when I went to lunch that the car detailer had come in to do his thing. That was the only thing that had changed since this morning when I was getting perfect results. I had left my fans running while I was at lunch and he was spraying a silicone-based tire/rubber/plastic cleaner. My fans must have pulled it in.

I called my distributor to ask his advice about my predicament. I asked about fisheye reducer, which he strongly recommended against. He mentioned something about paint Smoothie, but then said I could try to use ammonia. I did a test. I took a piece of rough stock and planed one face so I was sure it couldn't be contaminated with silicone. I sprayed a seal coat then a finish coat. No fisheye. Then, I went to the detailer and got some of his spray and sprayed it on my piece. I wiped it in, then wiped half of it with the ammonia. Then I sprayed another coat. The silicone half had unbelievably bad fisheye, but the ammonia-wiped half had hardly any. I believe this proved that this was my contaminate and that the ammonia would help alleviate my fisheye. Now I'm off to wash everything in my shop.

Forum Responses
(Finishing Forum)
From contributor A:
That's good to know. I note that you tried it on sealed and topcoated wood. I doubt that it would work on raw wood and may give unwanted visual effects.

From the original questioner:
I am using a pigmented lacquer right now, so even if it did discolor the wood it wouldn't matter. I did my test on the sealed piece but I had to use it on wood that had just a primer coat too. To make this work I had to do a little more. First, I washed the primer down with full strength ammonia. Then I used 320 sandpaper and scuffed the primer, which had already been sanded before it was contaminated. Then I washed it with ammonia again. I sanded with 320 grit but used a new piece of paper to make sure I wasn't re-contaminating it again. Then I was able to put on a topcoat. I did have some fisheye here and there but it was greatly reduced and very sporadic. Before washing, the fisheye spots were about 20 per sq inch, and after washing it was more like 1 per sq ft. That’s not perfect, but acceptable for the backs of the doors. I can only hope that the fronts of the doors, which were face down during the contamination period, are not going to be affected. My spray room has not been completed and was not affected. I have been spraying in the front of my shop temporarily.

From contributor B:
What was the reason given by the rep for his advice not to use fisheye eliminator? Smoothie is just another name for the same thing, so if your distributor tells you to shun fisheye reducer, and then recommends Smoothie, you need to find another rep. Obviously, if you're sucking in severely contaminated air over your work, you have to fix that. But as to the general caution about using Smoothie, there is no harm whatever in using a little to eliminate ordinary contamination issues.

From the original questioner:
The reason he gave me not to use the fisheye eliminator was that it was more or less like adding silicone to your mix. It would effectively stop fisheye but at the same time contaminate your spray system. Do you know what is in the fisheye reducer? He said not to use it and I have learned to trust his advice. He hasn't steered me wrong yet.

From contributor B:
Fisheye preventer/reducer/eliminator is silicone, as is Smoothie. There really isn't a significant downside to using fisheye preventer, unless you seriously overdo it. Conventional wisdom also says once you start using fisheye preventer, you always have to use it. This simply is not so. However, if you have problems with minor to moderate fisheye on a regular basis, it may make very good sense to add a measured amount of fisheye preventer to all of your finish. This way you have a consistent amount in the material. I do a lot of refinish work so this is how I deal with it and it has worked well. If your fisheye problems are infrequent, there is no problem using it only when the problem shows up.

From contributor C:
A word of caution - ammonia will turn some catalyzed finishes hazy.