Leave the pan inside the oven until it cools. Heat the oven to 350☏ and bake for 1 hr.Place a piece of aluminum foil or baking sheet on the rack below the pan to catch any oil that drips as it bakes. Take your pan and place it inside of your oven, upside down on your upper rack.Lightly rub any excess oil away with a towel or paper towels.Unsaturated oils, like canola or flaxseed, are best as they polymerize (combine) to the metal more easily. Do not use olive oil as the smoke point is too low and it will burn. The cooking oil you use is very important in this process. Don't forget to cover the outside and handle of the pan. Take your clean, dry pan and rub a thin layer of vegetable oil or shortening on the cast iron.Luckily, re-seasoning your pan isn't as difficult as it may seem. The process of removing all of that rust will have effectively removed, or greatly disturbed, your cast iron seasoning. The great news is you have now fully removed the rust from your cast iron cookware. Moisture is not this pan's friend! Seasoning your cast iron pan Towel drying is one of the most important steps in preventing more rust in the future. Then, take a clean dry dishtowel and thoroughly dry the pan. Wash your pan with mild dish soap and a soft towel to remove any leftover particles of rust, salt, baking soda, etc. No matter the method you used to remove the rust, you will need to give your cast iron a thorough cleaning.
The time has come to start over again from scratch. Your rusty cast iron has been restored to its original glory. Take a scrubber or a towel and rub thoroughly, concentrating on rusty areas.