How to clean rust off cast iron skillets. 

My mom used a white vinegar solution 2 parts vinegar 1 part water to clean

the rust off cast iron pans.

She would soak the pan overnight in the vinegar solution and the vinegar just dissolves the rust.

Very rusty pans may take an extra evening. Don't leave it in there too long or you will not have a pan. The vinegar actually dissolves the metal.

This would work on new cast iron pans also.

I  collect antique cast iron pans and after cleaning the old grease off them many times they are rusty

under the old seasoning.

I did not know it was this simple until my mother taught me, you know the moms out there are good for teaching us stuff after all. Who would have thought?