Cast iron cookware is made to last for many years. When cared for properly, the heavy metal pots and pans can be passed down from generation to generation. A cast iron skillet that doesn't receive proper care and maintenance can become rusty and lose its non-stick surface, causing food and grease stains to build up. Rather than throw away a cast iron skillet that's out of shape, you can refinish it, then use it for many years to come.
Scrub the dry cast iron skillet with a stainless steel scrub brush to remove any baked- or burned-on stains. Brush out loosened grime with a paint brush until you've removed as much as possible.
Remove rust from the inside and outside of the cast iron skillet by scrubbing the surface with a steel wool pad.
Rinse the cast iron pan with water to remove loosened stains and rust. Add a few drops of dishwashing detergent to the pan and scrub the skillet, inside and out, to wash away remaining rust and grime. Give the skillet a final rinse to wash away the detergent. Dry the iron skillet with paper towels.
Preheat the oven to 450 degrees Fahrenheit. Coat the inside of the pan with vegetable shortening and wipe the shortening around with a paper towel to ensure the entire surface is covered. Wipe off any excess shortening.
Put the cast iron skillet face-down on the baking pan. Cure it in the oven for 30 minutes, then turn off the oven and leave the skillet inside until it completely cools. Remove the skillet and wipe off excess melted shortening, if needed.