Vintage cast iron pans or skillets can generally be safe to cook with and eat from even if they have been left outside and have rusted. Cast iron is known for its durability, and rust can be removed and the pan can be restored with some effort. Here are a few steps to restore a rusted cast iron pan:
Scrub off the rust: Use a scrub brush or steel wool to vigorously scrub off the rust from the surface of the pan. Make sure to remove all the rusted areas until you see clean, bare cast iron.
Wash the pan: After scrubbing off the rust, wash the pan with warm water and mild dish soap to remove any residue. Avoid using harsh detergents or soaking the pan for extended periods, as this can strip away the seasoning.
Dry thoroughly: Thoroughly dry the pan to prevent further rusting. You can use a towel or place the pan on low heat on the stovetop to evaporate any remaining moisture.
Re-season the pan: Seasoning involves applying a thin layer of oil to the pan and heating it to create a polymerized oil coating that protects the cast iron. Coat the pan with a thin layer of vegetable oil or flaxseed oil, including the entire surface, inside and out. Place the pan in an oven preheated to around 375°F (190°C) for about an hour. Allow the pan to cool completely before removing it from the oven.
By following these steps, you can remove rust and restore the pan's functionality. It's important to note that when dealing with vintage cast iron pans, there may be other factors to consider, such as the pan's overall condition and potential contaminants. If you have any concerns about the safety of the pan, it's advisable to consult with a professional or consider purchasing a new cast iron pan for cooking.