If you are lucky enough to have got your hands on a piano stool that is fully functional but just needs refinishing to look its best, you can get it looking almost as good as new by stripping away the old finish and adding a fresh one. Most piano stools were finished with lacquer, which is best removed with a chemical stripper as opposed to sanding, which is messy, time-consuming, and difficult to do on carved designs present on the legs of many piano stools.
Take the seat off the base of the stool so that all finished sections are easier to get to.
Apply the stripper to the stool with an old paint brush according to the directions on the can, making sure you are wearing old clothing and gloves. Wait the recommended amount of time, and use the scraper or putty knife to scrape away the finish. If some remains, reapply the stripper until the old finish is gone.
Wipe any remaining finish and stripper away with rags. It may be necessary to use a small brush like an old toothbrush to remove the finish from carved areas and grooves along the legs of the stool.
Lightly sand the stool with a fine-grit sandpaper, go over with steel wool and wipe away the dust with a tack cloth.
Stain the stool with the desired shade of furniture stain, following the manufacturer's directions.
Finish by applying several coats of varnish, sanding in between each coat, or with a coat of Danish oil, a thinned oil and varnish blend.
Work in a well-ventilated area at all times, preferably outdoors. To create the blackened look popular on many antique piano stools, after staining, fog the stool lightly with black spray paint, allow to dry, and then seal with oil or varnish. Varnish is a more durable finish than Danish oil, which will dry out and disappear after a few years. When this happens and the stool begins to appear dull, you will need to apply another coat of Danish oil to remove the old film and put down a new finish.
Always wear gloves, as furniture strippers, stains, and varnishes can burn and stain the skin.