I love my cast iron pans, but this past winter we were using one of them as our steamer on top of our wood stove. It got pretty rusty and I was worried I wouldn't be able to use it again. I knew you could re-season a pan, but I was worried about the rust. The pan was salvageable, it just needed a little scrubbing.
I scrubbed the rust off, then wiped it all over inside and out with vegetable oil. Preheat your oven to 350F and bake turned upside down on a foil lined baking sheet for 1 hour. Wipe off excess oil if necessary when done. Ta Da!!