I have a Kohler purist faucet in my bathroom -- solid brass everything, chrome plated. I have had to replace the handles once before due to corrosion at the base of the top handle section. These are corroding again. Also, new, the steel retaining washer that clamps the center faucet to the sink corroded away entirely (turned to dust when I touched it)
I'm trying to figure out what I can change to minimize galvanic couples here. Should I swap out my supply tubing with non-metal reinforced, to isolate the valves from the supply? Or is a few drops of standing water at the interface between the brass and chrome enough to cause corrosion at the handle? The hardware underneath the sink looks like some sort of plated steel standoff. I think the large nut is brass, though I can't tell.
For the steel clamp washer, do I need to add a nonmetallic gasket between the nut and washer to try to keep is isolated? Should I install some rubber tube or Teflon tape around the threaded faucet stem where it would come in context with the steel washer, to try to isolate it? The center stem has a threaded section where a (brass?) nut was tightened against a steel clamp washer, then has a brass T with plastic tubing to the hot and cold valves. There is also a chrome drain lift, which connects to what looks like a steel extension before connecting to the brass drain trip.
Or, is this a problem that I need to putty better between sink and up top, to keep moisture from seeping below?