Q: My stained, solid oak kitchen table has a milky white circle caused by placing a hot bowl of soup on the table. How can I remove this white area without having to refinish the whole table? I would like to apply a spar varnish over the existing finish.
A: Start by cleaning the surface with either mineral spirits or TSP on nylon abrasive pads, wiping up the resulting slurry until it wipes clean. Sand lightly, then wipe the top with a cloth dampened with denatured alcohol. Make it damp, not fully wet, or it could damage the finish. Damp means “about as wet as a healthy dog’s nose.” A couple of swipes should remove the white marks and leave the table ready to recoat. Spar varnish would not be my first choice for recoating a kitchen table, because most spar varnishes are simply too soft. I think you will get better wear with oil-based polyurethane.