Matt

Go to your local grocery store and buy some Barkeepers Friend. It
contains Oxalic Acid. It comes in a container that looks like Comet
cleaner but is gold in color. Dampen the area and sprinkle some on. Let
it set for a little while then scrub the area. You might have to do this
2 times depending on how bad the spot is. The rust will disappear. I
will never be without a can or two of Bar Keepers Friend. Do a Google
search and you can read all about it.

Ron