There is a lot of old cheap rust removal tricks you can try with things you probably have at home
Sprinkle a little bit of salt on the rust, then squeeze the lime over the salt until it is soaking. Let the mixture sit for 2-3 hours and then remove the rust with the lime rind. This can also be done with a lemon. We like the salt and lime a little more because they double as margarita ingredients as well.
Vinegar Soak
White Vinegar
Baking Soda + Water
Hydrogen Peroxide
all work well with a little effort