Michael Dresdner

Q: I recently attempted to hand rub the polyurethane finish on a mahogany tabletop that I refinished and was disappointed with the result. The top has three coats of oil based satin polyurethane. The finish had a nice even satin sheen but felt like 220 grit paper. I then wet sanded with 600, 1000 and 1500 grit wet paper wrapped around a felt block, then rubbed with FFF pumice using a felt block and water lube. What did I do wrong?
A: You did not tell me if the finish was sufficiently cured, and that alone can undo your best efforts. Even so, you are going about creating a satin finish in a most difficult way. Here’s a simpler method that may work better.
Wait until the finish cures completely. For shellac and lacquer, two or three days will do; for oil based varnish and polyurethane, try to wait three weeks, and longer if you can spare the time. For waterbased, wait a month.
Smooth the top surface, removing any dust nibs, by sanding lightly with 400 grit self lubricated sandpaper. Sand only enough to remove the nibs – don’t over sand. Dip a pad of 0000 steel wool into paste wax and carefully rub with the grain. Do the edges first separately, as it is hard to rub all the way to the very edge of a surface. Keep your hand flat so you can rub right up to the edge without rounding the steel wool over the corner, which would cause you to rub through the finish. Once the edges are pre-rubbed, concentrate on the bulk of the top surface. Rub in very straight lines side to side, with the grain, across the entire top. Overlap your strokes and cover the entire top with at least six passes back and forth. That will guarantee a uniform fine scratch pattern from the steel wool, and the finish should look like finely brushed brass. Add more paste wax as needed for lubrication.
When you are done rubbing, immediately wipe off all the wax with a soft cloth, but that may still leave enough wax to smear. To remove it, sprinkle the top with cold water. Take a new, clean 0000 steel wool pad and gently go back and forth in the same rubbing pattern. Go over the surface once lightly, then flip the pad and do it again. Use no pressure other than the weight of your hand. The cold water will congeal the wax, allowing the steel wool to remove it. Wipe off the water and admire your work.

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This entry was posted on Friday, February 26th, 2010 at 9:00 am and is filed under clear coat, rubbing out. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.