Two finishes, same problem

Troubleshooting the cause of a problem existing in each of two distinctly different types of finish. April 8, 2000

Q.
I have tried spraying Resisthane and Wat-R-Base from Compliant, both with the same results: craters up to 1/8 inch (and smaller) in diameter. I do not use stearated abrasives, have followed all the manufacturer's guidelines, and still the craters come back. I use a Titan 4-stage turbine spary system and have tried everything I can think of to remedy this. Any ideas?


Generally it will come from surface contamination.

Wipe down with denatured alcohol or a wood prep. It may not be the stearated paper, but the sandpaper can still be the culprit. A fish-eye additive can help, but could also be covering up the problem. A temporary fix, of sorts. But with two distinctly different finishes? Depending on equipment, there may be some contaminant in the line somewhere. Eliminate one thing at a time: spray on some glass; don't sand; use someone else's rig, etc.


I will try to spray on some glass and see what happens. I am not getting the craters all over, just in a few places (for instance, approximately five on a drawer face).

By the way, I noticed Resisthane is now called Resisthane Plus; has anything changed with the finish, or just the name?


The Plus is different than standard Resisthane. It allows 30 percent fewer coats because you can apply much heavier (thicker) wet coats and it still dries as fast, if not faster, than the standard. It is slightly harder, too. All the other characteristics are identical. Both types are still available.

These finish craters: I assume you are referring to fish eyes. You have to find the source of the problem. Adding a fish-eye eliminator to the topcoat is like playing with fire. Possible causes for fish eyes are many, and if random, are hard to pinpoint and stop. I am basing this on personal experience: At one time, I more than welcomed the adding of fish eye eliminator to a topcoat in a finishing room. Now, it is strictly taboo. I do refinish work from time to time in my home shop, where a fisheye eliminator is almost a must -- but that is small-scale, usually a few pieces at a time.

Here are a few things that I have found over the years to cause fish eyes. Keep in mind there still could be other causes, but these are sometimes overlooked: certain underarm anti-perspirants; some spray lubricants (read the label to see if it contains silicon); some hand lotions; some hair sprays, mousses, and gels; and there may be a lot more.

The best thing to do is take a scrap piece of wood, rub some of the suspected products on the panel, and write above them what they are. Try not to rule out anything used in the finishing room, period. Spray the panel, and see if it fish eyes and/or crawls. If so, don't ever allow that product in your finishing room again. Some people won't like this, but they'll get over it, and it's the best way to solve the problem. If you have to, test all products within the plant, especially airborne, aerosol-applied lubricants.

Also, if you are working to salvage a returned product that has been in someone's home, remember that if they used furniture polish on it, it could contaminate your finishing room when you sand it. So when doing this, always thoroughly wash the piece with lacquer thinner, wax wash, or naptha to remove the wax before sanding or stripping. This doesn't always work, but usually takes care of potential problems.

Adding fish-eye eliminator to stop the problem is like trying to put out a fire with gasoline.


Adding fish-eye additive (for solvents) that contains silicons creates more problems, for sure. However, the additive for a water-based product is generally a surfactant that weakens the surface tension, allowing the finish to flow. It does not contaminate the finish or the equipment.

It should be used to eliminate a problem when it happens, allowing you to finish the project; not as a preventative that is used all the time. The contaminants noted are definite problems with any finish.

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