I have never done this but it should work.

Clean the area with a soap solution and then with vinegar.
Get it as clean as you can
If rusty sand it with medium emery cloth till clean.
If the area is a little rough the coating will adhere better.
Then I would get a bottle of the stuff that is used to repair dishwasher racks.
It has good adhesion and soap has no effect on it.
I would paint on several light coats instead of one heavy coat.

Could also use an epoxy buy get one that is optimized for metal.
5 minute epoxy will just peel off after a few washes.

Perhaps someone else will have personal experience with this a specific epoxy to use.