The basic steps for reseasoning cast iron are cleaning the cast iron thoroughly, applying a thin layer of oil and then heating the pan. Reseasoning requires an oven, a scrub brush, dishwashing liquid, vegetable oil and potholders or oven mitts. If the pan is rusty, a scouring pad also helps.
Begin by scrubbing the cast iron with warm water and a small amount of dishwashing liquid. If the pot or pan is rusty, use a scouring pad to remove the rust. Rinse the cast iron free of any soap residue and dry it thoroughly. Heating the pan over low heat as it dries helps evaporate any remaining water and opens the pores of the iron to receive the oil.
Oil the clean, dry pan all over, including the handle. The American Skillet Company recommends flaxseed oil, but regular vegetable oil works, too. Wipe excess oil away with a clean rag or paper towel until the iron appears dry. Place the pan upside down in the oven with a baking sheet or aluminum foil on the shelf underneath it to catch drips. Bake the pan for one hour at 350 degrees if using vegetable oil and 450 to 500 degrees if using flaxseed oil. Allow the pan to cool in the oven or remove it to a wire rack to cool for at least an hour. Repeat the steps of oiling and baking up to six times, or until the desired finish is attained.