Bob Couch replies: I have had the same issue with cabinets in the past that were finished with non-commercial urethane/varnish products. Although these products are quite hard and durable, the finish will soften over time from the oils and contaminants on people’s hands. Just think about how many times a day you open the cupboard door to get a glass or open the silverware drawer.
I have had reasonable luck with a couple of products to clean and freshen the area around the handles and pulls.
Murphy’s Oil soap is one and the other is called Cabinet Magic, which I believe I bought at Home Depot.
I would first remove the hardware to help give you better access to scrubbing the affected areas clean. If you are happy with the results and would like to protect the finish, look for some Butcher’s Bowling Alley Wax and apply a coat of wax.
If you feel refinishing is in order, a light sanding will prepare the surface for a new coat of finish. To insure a good mechanical bond in case there is any residual oils are present, I would spray or brush on a coat of Zinsser’s Sealcoat dewaxed shellac prior to any finish coats like varnish or lacquer.
Given the durability factor required, I would eliminate lacquer as a good option. That leaves a varnish of some flavor. Varnish is a generic term that refers to final coats of finish in oil or water based products. Alkyd or polyurethane varnishes are typically the finishes available in paint stores and home centers and would provide a reasonably hard protective finish. Behlen has a product called Rockhard Table Top Varnish that claims to be harder than regular polyurethanes.
The most durable finish available to us is conversion varnish. This product is a fast-drying finish that comes in two parts: the finish and an acid catalyst you add to the finish just before spraying. The catalyst brings about the cross-linking. Conversion varnish is rarely available in paint stores or home centers. It’s usually found only through specialized distributors or directly from manufacturers. This is largely because it is a very “unfriendly” finish for non-professionals. In addition to knowing how to spray and tune and clean a spray gun, you have to be precise in the mixing of the two parts and accurate in the thickness of the coats you apply because too thick of a film (more than five mils) is likely to crack. Good info on finish comparisons can be found at www.woodshopnews.com, then search for this article—For resistance, varnishes are tough to beat.
If conversion varnish is your choice, there are several folks around that would spray your doors and draw fronts for you and could probably deliver a finish that would still match the rest of your cabinet finish.