Rubbing out varnish

[Dave Novak]

I'm having one heck of a time achieving a glass-smooth high gloss surface on a table top. I've built up plenty of coats of Behlen's Rock hard on red oak. The last coat (wiped on 50/50 diluted) always leaves dust nibs or tiny bubbles. So, after a couple of days of curing (in a garage, 55 degrees) I'll sand it smooth with 2000 grit Platin 2 (a festool foam-type abrasive) on my ROS. With very little effort it feels like glass, but I lose the gloss finish I'm after. So I wipe on another coat of diluted BRH, and of course, every time, more very tiny bubbles/nibs. I've heard the definition of insanity is doing the same thing over and over hoping for a different result, so instead of going insane I'm looking for some direction.

I have Platin 2 in 4000 grit, if I move to this will I increase my chance of keeping the high gloss look while removing or at least smoothing out the bubbles/nibs? Should I scrap the ROS and wrap the platin around a sanding block and work by hand? Use some paraffin or mineral oil? Could it be that I just need to let the finish cure longer?

[Jerry Thompson]

It needs to cure longer than a couple of days. Thirty would be more like it.

[Scott Holmes]

30 days at 72 more like 90 days at 55... below 60 will greatly increase the curing time. A fan blowing over the dry to the touch surface will speed up the curing process.

Also, rubbing out a finish is not complete with 2000 grit paper. That will leave it a bit more shine than satin. You will need to go beyond 2000 grit; and all sanding during a rub out should be wet sanding with MS or mineral oil as the lube.

One more item I noticed... and you should rub out the finish after the last 3 or 4 wipe-on coats. NO sanding between coats. One wipe on coat will not leave enough finish to sand without sanding through the last coat.

[Dave Novak]

Thanks guys, makes perfect sense. I brought it in the house to dry, I'll wait a month to buff it out. This is a christmas present for my folks, I joked when they asked me to build it that they should plan on it being an easter present, and I might not have been too far off. At least I can go back to making dust now!