Out, out, hardwood spot, part 2

When last you heard about my oak floor, I was trying to quickly spot-sand and spray-varnish an annoying blemish under the polyurethane finish and experiencing less than perfect results. Veteran floor doctor Roy Reichow, in East Bethel, Minn., took time out between wood-floor rescues to share some tips. First, he points out, my finish has ambered over time. (I like that word, ambered.) To match it, he says, pour some polyurethane in a small glass jar and place it in a window for about a week, then try it out.  If it’s not ambered enough, put it back in the sun again.  He also suggests taping off the area to be treated and pulling up the tape while the finish is still wet so it doesn’t leave a ridge.  Now all I need is suggestions on how to improve my spot-sanding technique. Incidentally, neither Roy nor the experts at This Old House are crazy about the idea of waxing polyurethaned floors. Here's a quick tip on how to remove wax that’s already there.