I have 30 yr old cherry cabinets that are in very good condition but have some worn spots around the hardware and we want to stain the cabinets a darker color. Several years ago I applied a coat of polyurethane on them but now want to stain them a shade or two darker. I have read that polyshades can be applied over this finish but not sure if that's the right way to proceed. Any suggestions?
Assuming that the current finish is oil-based and in good condition (not peeling, chipping, etc), you can use the polyshades over this finish. Be sure to lightly sand and clean the cabinets first and then apply two coats of the finish. Be sure to do at least two coats - the first usually looks like crap, so two are necessary.
Going this route will limit you when it comes to colors though.... and, as always, be sure to test the finish to make sure you're happy with the results before you commit to it.