Water Cooler: How to restore a cast iron pan

If you have some cast iron pans that were handed down through your family or that you dug up at an estate sale, restoring them makes for a great quarantine weekend project.

There are a few things to look to determine whether a piece of cast iron is worth restoring.

First, do a quick visual inspection for cracks. If you can’t see any on the surface, hold the pan up and rap it with your knuckles. If it rings with a bell-like resonance, then it is likely free of cracks. If it gives a dull or clipped sound, then there is likely a crack covered by rust or seasoning that you can’t see. In that case, the pan is not worth using as it will eventually break.

Check the pan for pitting as well. Pitting is chemical erosion of metal and results in a rough surface of small craters in the pan. A small amount is fine, but too much will result in uneven seasoning.

Check the color. Dull red color is an indication of heat damage. It is irreversible, and it can be difficult to build seasoning on top of it. This is a different red color than the brighter orange and brown of rust.

Once you’ve determined that a cast iron pan is worth restoring, you want to strip it down and build up the seasoning again from scratch. There are several methods used to strip cast iron pans, with advanced techniques involving lye baths, electrolysis and molasses soaks, but these basic techniques should do the job for most restoration projects.

To strip old seasoning, spray the pan with a lye-based oven cleaner spray. The cleaner should have sodium hydroxide, the chemical name for lye, as the main ingredient. Something with a thick foam will easily coat the pan and stay in place to soak the surface. Make sure to spray this in a well-ventilated area, ideally outdoors. Prevent the foam from drying by wrapping the pan in a plastic garbage bag, and place it in an old tub or disposable roasting pan. Let this set for at least 24 hours. This could take several days and reapplication of cleaner. Repeat until everything is softened and any gunk can be rinsed off.

To remove surface rust, soak the pan in a one-part white vinegar and one-part water solution for 30 minutes. Remove and scrub the pan with a steel wool or a steel scouring pad. If you find not all the rust has been removed, repeat this process. Vinegar baths are acidic solutions, so keep them to 30 minutes to avoid eroding the iron.

Once the pan is stripped, gently scrub it with soap, rinse with water, wipe down with a rag, then set over a flame or in a 350-degree oven for a few minutes to completely dry. Flash rusting may occur due to immediate oxidation. This is normal and can be prevented by an initial seasoning.

There are tons of different seasoning methods. A simple method is to remove the hot pan from the oven and wipe down with oil using a terry cloth. Use any neutral oil, such as canola or grapeseed, or shortening. Cover every inch of the pan, handles and all, wiping vigorously to create a thin layer of oil and glossy sheen.

Return pan to the oven, upside down, for 15 minutes. Remove and wipe again, then return to the oven for 30 minutes. Turn the oven off, prop open the door and let the pan cool slowly in the oven. Repeat this as many times as you wish to establish the seasoning, or build the seasoning through cooking.

Rachel Baker can be reached at (509) 459-5583 or rachelb@spokesman.com