Fixing a fisheyed finish

Troubleshooting fisheye problems in a conversion varnish topcoat. June 24, 2001

I'm having fisheye problems with Sherwin Williams Conversion Varnish High Gloss.

I shipped a set of doors out in good shape. The contractor rejected the doors due to fine sanding scratches. I used a Sherwin Williams dark eggplant stain that shows everything.

I applied another coat of varnish to solve the problem, but that coat fisheyed. Sherwin Williams and I spent weeks trying to solve the problem. The only solution was to buff all the doors, but you need to block sand to get the fisheye out. After sanding, the finish was too thin to buff. I re-coated and got more fisheye. What is wrong?

Forum Responses
Have you checked your spray equipment and compressor? You seem to think that the fact that you are using gloss C-V matters, and I just don't see what the sheen has to do with it. Fisheyes occur because of oil/silicon contamination of the surface of the object, preventing the paint from wetting it. Something is contaminating the surface. What brand and part number of sandpaper are you using? Some stearates can cause fisheyes.

I buy the water white conversion varnish and I've not had a problem with it, although I do use the medium rubbed effect rather than the gloss. If you believe the problem is the paint, go to A.G. Layne on Sixteenth Street and buy some Lilly Resistovar or go to Akzo Nobel and use their C-V, which they call Rel-Plaz. If these also fisheye, the paint can't be the problem, as the three largest manufacturers of wood coatings in the country can't all have the same problem.

You and any employee who touches these doors should wear rubber gloves throughout this process. I like the thin un-powdered blue nitrile ones. Repeat your sanding and take off as much of the C-V on the door as you can before hitting the stain. Use a different brand of sandpaper this time when you sand. I'd recommend 3M 216U sheets or 255L free-cut gold discs which are the same material. After thorough sanding, wipe down everything with naphtha and a brand new cotton rag made of tee shirt material. At this point you should have things as clean as humanly possible.

Get a brand new can of the S-W water white conversion varnish and catalyst with a different batch number on it from that which you have been using in gloss and using a friend's gun and compressor, shoot this on and see what happens.

If this batch doesn't fisheye with the different equipment, the problem is probably your spray equipment. If it does fisheye, you must completely strip the doors and try Resistovar or Rel-Plaz and see what happens then.

S-W sells tens of thousands of gallons of C-V a year. It would seem unlikely that the paint is the problem.

Out of the three above-mentioned products, I strongly recommend Akzo-Nobel's Rel-Plaz. I have refinished pieces that tried to fisheye due to contamination of the wood and was able to use some fisheye eliminator in the Rel-Plaz without the normal adverse affects of adding a fisheye eliminator to a conversion varnish.

The tech support that I got from CCI in Hudson, NC on their conversion varnish suggested using a xylene wipe. They suggested that the xylene was a better cleaner on their conversion varnish.

Also, are they fisheyes or is the product wrinkling?

A workaround suggested by ML Campbell on their catalyzed coatings is to shoot on a thin application of vinyl sealer before topcoating. The vinyl sealer will stop the new conversion varnish from biting into the previously applied coats which have now been sanded too thin and want to crosslink, not resolvate (if I have that right about re-coat windows).

So, some of this may be applicable to your situation and some of it may be just bookish generics.

Try a product from Mohawk finishing supply call Silicone Stop Sealer. I have had some success with this. Reduce it, though. Where can I find this Rel-Plaz?

Rel-Plaz is available from Akzo Nobel.

Watch out with the rubber gloves. We had the same problem and it ended up being the disposable gloves supplied by our paint supplier (don't recall the brand). It was the powder they put on the inside to help the glove slip on easier. If you're using gloves, turn them inside out and wipe them on a piece of wood and spray it with finish.

Somewhere in the shop is the problem. Once in awhile, it can be the coating. But I have seen more cross contamination in shops than anything else. There are several different silicones you can add without adverse affects. You can only fight silicone with silicone. Many manufactures do add a small amount of a silicone to the product, as it helps with the feel of the product and adds some "slip". Silicone is not taboo to have around when needed. Automotive guys use tons of it in refinish work.

Bob Niemeyer, forum technical advisor

While it may or may not apply to this particular discussion, this article is interesting reading.
The Great Fisheye Hunt

Assuming the culprit, silicone, was contaminating the wood, wouldn't a barrier coat of blond shellac have taken care of the problem?

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor H:
If all else fails, you can sand down the finish until smooth and seal it with shellac. I use Zinser Bull's Eye Shellac. Then lightly sand and coat again.