When I moved into the house I currently live in the landlord left a set of cast iron skillets and said we could have themThe only problem is that they have rust on them and it looks pretty bad and like it has been there for a while.Is there a way to get the rust off and it still be usable for cooking? I was thinking of an SOS pad or sand paper but am not sure if it will ruin the pan.I have never had a cast iron skillet before so how do I season it or prepare it to be used after getting the rust off?