HOME > Chowhound > Cookware >

Discussion

Restoring ill-used cast iron

I like to buy old cast iron at thrift stores and sometimes find it covered in decades worth of baked -on gunk. What's the best way to bring these old pieces back to use?

  1. Click to Upload a photo (10 MB limit)
Delete
  1. Scrub (with steel wool pads), rinse, scrub, rinse, put in a self cleaning oven (run through the cycle), scrub, rinse, oil, bake (season). Use.

    1. This is going to sound nuts, but I use an angle grinder with a knotted wire brush. You have to do the work outside, with a dust mask and protective eyeware, but it takes about 10 minutes to get to the bare metal over the entire pan. I then wash, dry, and season. To season, I coat the whole pan (inside and out) with vegetable oil, wipe off the excess, and place in a 400°F oven, upside down, over foil (to catch the mess). I turn the oven off after 10 minutes, and leave the thing in there until it's cool.

      1. be sure to read the "without crisco" posting. it pretty much tells you what you need to know

        http://www.chowhound.com/topics/433869

        1 Reply
        1. re: KaimukiMan

          This thread is a "spin-off" as the postest with the mostest requested I start a new thread for that topic. I need to know how to get to the point where I can start seasoning.

        2. There have been many good suggestions on getting the gunk and decaying metal (rust) off the cast iron pan. Once that is done and you have seasoned it. Use a black light (the tube type operated by batteries) and look at the pan in the dark. You will see any areas that need more work. While your at it you might want to surprise your self by what you see on the outside of your refrigerator, stove, backsplash, etc. WOW

          1. run it through the self cleaning cycle of your oven. When it comes out and has cooled a bit you will see some rust residue. Just wash that out, dry over heat and begin to season.
            The old fashioned way was to burn them out in the fire place or just iin a fire. This way is safer and easier.

            1. No self-cleaning cycle here. The thermo does go up to 550 degrees, would that do any good?

              11 Replies
              1. re: OldDog

                No, that sadly won't be hot enough.

                1. re: Candy

                  Thanks, Candy...guess I'll have to wait 'til "burn season" and throw it in the fire, maybe several times.

                  It's a much-abused (the inside is gouged, as if someone tried to chip out the old seasoning with a scew driver or some such, but surprisingly little rust) 10" x 3" Martin brand with lid, made in Florence, Alabama.

                  1. re: OldDog

                    In the meantime, you could try taking it to an auto body shop and ask them to sandblast it. If you're not in any particular hurry, just ask them to blast it the next time they have a car in the booth - that way, they don't have to crank up the blaster just for your pan, and their incremental effort will be minimal. They may not even charge you for it.

                    1. re: ricepad

                      ricepad:
                      I'd have never thought of a body shop or of sand blasting for that matter, thanks much for the idea. I'm going to call the local shop tomorrow and see what they have to say.

                      Alan408:
                      The pan isn't gummy at all and has very little rust, so It doesn't look like any amount of boiling/scrubbing would do much, but I appreciate that you took time to try to help. Thanks! We DO have one of those Turkey Fryer burner things, so wonder if doing a 'burn off' on that might get the pan hot enough to work. Anyone have an opinion on that?

                      1. re: OldDog

                        If you can't find a body shop to do it for a reasonable price, try a community college that has a body & paint class.

                        1. re: ricepad

                          That's another great idea, ricepad. Thanks again!

                        2. re: OldDog

                          The common theme to this seems to be really high heat. Those fryer things have to put out a lot of BTUs so it just might work! If you're brave enough to try it, let me know how it works.

                          1. re: WCchopper

                            As it turns out (taking a deep breath...lol), DH has a friend who stopped by today, who knows a guy who has a friend who restores old cars, so he's going to check on the possibilty of getting said friend to sandblast the pan for me next time said friend is sandblasting whatever old car restorers sandblast.

                            This may or may not take longer to get done than my allotted days on the planet, but I guess it's better than risking burning the whole place down with the turkey burner, according to DH.

                            I guess... ;-)

                            1. re: OldDog

                              Follow up on my much-abused pan saga... (I'm always disappointed when follow-ups don't happen, so forgive me if this bores or annoys you.)

                              Friend of friend (of friend) sandblasted pot and lid and returned it early last week in all its raw, pristine glory. I scrubbed it out using a fine grade steel wool, soap and water, dried on the stove top and then got with the program.

                              Preheated oven to 550f, placed (an already nasty) cookie sheet on the bottom rack, rubbed surfaces of pan and lid inside and out with lard and put on next highest rack, upside down. Let it go on heat for about 6 hours, then turned off the oven and left it in overnight to cool, since potholder started to smoke when I tried to pull it out, lol.

                              I repeated this process three times, 'larding' all surfaces, and two more times coating only the inner pan surface and letting it go on heat overnight, always leaving it in oven to cool.

                              Thursday, I used the pot and lid to make the Lahey No-Knead bread and am thrilled to report that it didn't stick at all.

                              Thanks very, very much to Annabelle and all who helped, I'm a very happy camper with a great pan!

                              1. re: OldDog

                                So, a total of 6 times 6 hours at heat with a cool down inbetween?

                                1. re: WCchopper

                                  The first time was about 6 hours then oven off and left to cool. After that I let it go all night with the oven on 550f, but you don't really need to do that if it makes you nervous or you need to use the oven. I just figured it couldn't hurt.

                2. A few weeks ago, I was in Alaska at a fishing lodge. "They" had an old large (14"-16") rusted and with some "gunk" cast iron pan.

                  "They" put the pan over a high BTU burner (probably a Turkey Fryer burner), put some water in the pan and heated until boiling. Every so often, "they" would shut down the burner and scrub out the inside with what looked like an old t-shirt. I saw "them" do this a couple of times. "They" probably did this 6-8 times, the next day the pan looked ready for seasoning.

                  So, I guess boiling and scrubbing works too.

                  1 Reply
                  1. re: Alan408

                    Sounds like the water is just something to wash out the skillet with. It's the high heat that you're looking for. Like "quotation" marks? ;-)

                  2. I've heard a good way to do this is if you have a charcoal grill fire it up real good and set the cast iron right on the coals and let it bake.

                    1. Sorry to take so long to answer :) I got carted off by relatives for the holiday. Use lye, the high heat method is something new to this century, and not that good on cast iron. Ignore any suggested use of the "cleaning cycle" in modern day ovens, temperatures vary. Not to mention, any uneven rapid heating will warp or crack your iron. In the old days, contrary to what's posted elsewhere -- high heat was not used. A self cleaning oven heats to 900-1200F; back in the days of no air conditioning, no one in their right mind would fire up a wood stove to that temperature and leave it there for several hours for a piece of cookware. Lye was the standard, and also the main ingredient in homemade soap of the era.

                      Baked on Food: Two options, Lye Bath or Oven Cleaner (which is also lye in a convenient package).

                      Lye Bath - (this is how it has been done for 100's of years)

                      Large Plastic Washtub or Trash Can - Do not use metal! Back in the day metal was used, but the lye can eat thru it. If they had a leak with the tub outside in the dirt, no issue. But we have problems with property damage, domestic pets etc. Use plastic.
                      Can of Lye, you can get this at the grocery, it's likely found in the drain cleaner isle.
                      Plastic or wooden spoon/dowel/broom handle etc.
                      String, Goggles & Rubber Gloves. Back in the day, the pieces were just fished out of the mixture with bare hands or sticks.
                      Wear old clothes, lye may eat fabric resulting in holes where any splashes occur.

                      Fill plastic container with 4-5 gallons of COLD water, put on goggles & gloves.
                      Add Lye powder and stir with spoon/stick etc.
                      Tie string to handle of piece or place in mixture using gloves, do not get mixture on your skin. Secure string so that you can remove piece in a day or two when it's done.
                      Let stand until food particles are gone, remove from mixture. Be very careful removing the piece, if you used any natural fiber string; the lye will eat anything organic. This can result in the piece dropping and creating splash!
                      Rinse piece in COLD water progressing to warm and wash it several times to remove lye residue.
                      Dispose of lye mixture safely.

                      > Using warm/hot water or adding water to the Lye will result in a strong chemical reaction (boiling). Always add lye to water, never the other way around. Warm water can expedite the process, but can boil over creating excessive mess and/or property damange. Never use hot water.

                      Oven cleaner -

                      Plastic Garbage Bag
                      Oven Cleaner, Gloves, Goggles if you feel the need.

                      Spray cleaner on piece, place in bag for a few days until food can be removed with little effort.
                      Wash piece with cold water progressing to warm until all residue is gone.
                      Disgard plastic bag in trash.

                      With either method, take exceptional care if you have children/pets around, or where children/pets might have access to either chemical, or your tub/plastic bag.

                      Rust: Naval Jelley or Vinegar Bath, Vinegar bath is the "old fashioned" way.

                      Naval Jelley -

                      Will remove the rust faster than Vinegar and leave more of the metal behind.
                      Just wipe on and you can use steel wool/salt/sandpaper as an abrasive if needed.

                      Vinegar Bath -

                      Soak in 50/50 Water/Vinegar solution until rust is gone. This will address any white residues also, they are mineral deposits from water.

                      With either method, make sure to wash the piece well then dry using stovetop or warm oven.

                      Plan to begin seasoning as soon as your piece is dry! The bare metal will rust quickly just from environmental moisture (humidity). As long as the first coat of
                      lubricant is applied and piece has been heated, it should be good enough if you want to resume seasoning the next day. Complete info on seasoning discussions can be
                      found at http://www.chowhound.com/topics/433869

                      -Annabelle

                      1. Here is a link to the Wagner & Griswold (cast iron collectors) Society cleaning and seasoning advice web pages:

                        http://www.wag-society.org/cleaning.php

                        1. Here's the library of methods I've collected over several years:

                          Seasoning Cast Iron:

                          Cook lots of bacon or fry chicken; wipe out and then bake at 300, upside down over a pan to catch drips, for 2–3 hours. Repeat at least twice more.

                          Peanut, corn and grapeseed oil have high smoking points and so don't burn off.

                          Lard is traditional and works well.

                          Polyunsaturated oils (e.g., corn, peanut) leave a sticky surface. Try safflower or food-quality linseed. One source says you have to get rid of all double bonds, at high temperature (400) for 1 hour with window open to vent smoke and then let cool down in oven. However, if you cure polyunsaturated oil at high heat, it will carbonize, produce a smooth, hard layer and work well.

                          The coating will build up and be like candle wax. If it gets too thick or goes rancid, heat over charcoal or in a hot oven for 5 minutes and wipe with paper towels.

                          Don't use cast iron for beans, which stick and pull off the coating of seasoning.

                          Put a light coat of oil inside and out before storing. Then, particularly in hot weather, prop the lid slightly open, or the oil will go rancid.

                          To remove burnt-on crud, put it on the stove, half-filled with water and bring it to a simmer, pour out the water and whisking it with a straw wok cleaning brush.

                          Coca Cola has phosphoric acid, which removes crud.

                          Get that pan screaming hot, and while it’s still damned hot, scrub it with a heavy-duty stainless steel scouring pad and kosher salt. Scrub it down to the bare metal, which is actually pretty easy when the pan is so hot. Then schmear it with shortening and crank up the heat again, for a while.

                          For ridged surfaces, use a metal-bristle welding brush.

                          Remove rust from old cast iron by baking in a self-cleaning oven or scrubbing with steel wool. Barkeep's Friend also works. Scouring powder with a halved raw potato works for stubborn spots, or use a slurry of vinegar and salt. For otherwise unremoveable heavy rust, CLR works very well, but smells awful. The Best is Carbon-Off, http://www.discoveryproducts.com/inde...

                          For pitted cast iron, have everything ground and polished out at a metalworking or cast iron shop.

                          Restoration of really revolting cast iron:
                          1. Wear rubber gloves and eye protection while cleaning cast iron since the methods require using caustic chemicals.
                          2. Begin by spraying the pan with oven cleaner and putting it in a plastic bag.
                          3. After a day or two, take it out of the bag and scrub it down with a brass brush.
                          4. If all the grease doesn't loosen up right away, repeat the process concentrating cleaner on stubborn spots.
                          5. If you have several dirty items, soak them in a solution of one and a half gallons of water to one can of lye mixed in a plastic container.
                          6. Allow them to soak for about five days, then remove the pieces and use the same brass brush method to scrub them clean.
                          7. Removing mild rust should be done with a fine wire wheel on an electric drill.
                          8. Crusted rust can be dissolved by soaking the piece in a 50 percent solution of white vinegar and water for a few hours.
                          9. Once the pan's clean, begin the seasoning process by warming it in the oven for a few minutes then applying a little shortening, vegetable cooking spray, lard or bacon fat.
                          10. Put the skillet back into a 225 degree oven for 30 minutes. Remove and wipe it almost dry to eliminate any pooled grease.
                          11. Place the pan in the oven for another half hour or so, completing the initial seasoning.
                          12. The seasoning process will continue with use, especially if you use it to cook fatty foods (bacon, sausage, fried foods, etc.) the first few times it hits the stove.
                          13. To clean after cooking, boil hot water in the pan. Let it soak for several minutes and then wipe dry with a paper towel.
                          14. Reheat the pan and apply just enough grease to wet the surface before storing.
                          Tips:
                          Use the methods above only for cleaning iron.
                          Don't soak pans in a vinegar solution more than overnight without checking them because the solution will eventually eat the iron.
                          After cooking, do not use detergent or scouring pads to clean a cast iron pan since this will destroy the seasoning.
                          What You Need:
                          Rubber gloves
                          Eye protection
                          Spray oven cleaner
                          Large plastic zip bag
                          Brass brush
                          Barkeep's Friend or Bon Ami + ScotchBrite pad will clean any surface, and convert a mirror finish to brushed, which takes less care. Particularly good on stainless-lined copper. Oven cleaner works great and is very easy.
                          For intractable stains, rub on a thin paste of vinegar and cream of tartar, let sit and scrub off.

                          1 Reply
                          1. re: KRS

                            Just wanted to point out that some of your re-seasoning suggestions, KRS, are 180 degrees opposite those of acmorris, above, and at the following link:

                            http://www.chowhound.com/topics/43386...

                            For instance, acmorris doesn't recommend cooking spray at all, or oiling a cold pan before storing. I especially noticed the discrepancy in burn temperatures recommended. Not trying to be contrary here; this is just an FYI for anyone reading...

                          2. Historically, beeswax was used for seasoning and is now being recommended again.