We have been discussing touching up catalyzed finishes and my buddy Kevin Kamberg, an expert on this, provided a few tips to share. Today we will continue with his discussion. Please refer back to last week’s article where you will find the important beginning steps to using his techniques.
If the finish is fairly thick then there can be a problem if a run/sag area has completely filled the wood grain resulting in the repaired surface looking unlike the surrounding areas where you don't have the grain completely filled. Usually this can be fixed well enough by carefully using a coarser grit sand paper (220 down to maybe 120 at the absolute coarsest) and being careful to sand with the grain to recreate the appearance of pores. Then, use the mist technique, but even lighter, to reflow just enough to hide the sanding while preserving enough of the sanding grooves to simulate wood grain. This actually works pretty well but it can be time consuming to dial in just the right grit and just the right amount of reflowing. It is much safer to step down in grits than to go too course and create other problems.Keep in mind, of course, that you are removing part of a finite amount of the remaining lacquer. Don't burn through!
Here again, we will use the same basic approach as above except there's no need to shave anything off. And while wet sanding won’t hurt, in my experience, dry sanding is usually sufficient. If the orange peel is bad enough it's usually safer and quicker to spot spray the area and then deal with the overspray.
That said, if the overspray is really light, rub the offending surface with hard paper - a timecard or the backside of sandpaper - to see if that'll fix it. The hard paper basically knocks the overspray particles off the lacquer surface without being so abrasive that it affects the sheen or is otherwise visually noticeable. This is an old finisher’s trick that works surprising well. But even if it doesn't work well enough to pass muster, it removes some of the problem, resulting is less work with the sanding and reflowing.
Heavier overspray can usually be dealt with by sanding lightly with 320 grit and then reflowing. I've read that the sanding grooves left by 320 and finer are too small to be seen by the human eye, whereas 220 and courser are noticeable. My point being that sanding down with 220 may result in the need to completely re-spray the area if the sanding marks don't reflow enough to hide. 320 doesn't polish, so it's the perfect grit for this application.
Goobers in the Lacquer
These could be anything from a dust particle to some sort of floating debris or even a bug. Flying bugs, especially gnats, seem to be attracted to fresh lacquer. I don't know why but it's very rare in my experience that any other sort of bug will land in fresh lacquer.
Provided whatever the debris is doesn't leave a visually offending remnant, the fix is the same as above. Abrade it smooth and reflow the surface.