Remove rust from an iron skillet?
September 2, 2014 11:58 PM   Subscribe

I bought a new cast-iron skillet a few weeks ago. After coming into contact with salt water before I even got a chance to use it, a fair amount of rust appeared. What's the easiest way to get it off? I want to start seasoning it.
posted by jshare to Home & Garden (16 answers total) 11 users marked this as a favorite
I've restored a number of cast iron skillets I bought at flea markets. Oven cleaner for grime and grease removal. Use a drill with a wire brush bit for rust removal. Clean well to get rid of metal dust. Cleaning with water and soap will cause the surface to oxidize slightly right away. Don't worry about it. Rub it completely dry with paper towels and season it immediately after.
posted by Hairy Lobster at 12:37 AM on September 3, 2014 [2 favorites]

You're not restoring the pan, you're removing a little rust. Put away that drill! (Although that's EXCELLENT advice for a well-made, vintage, and uncared for pan...)

I wouldn't use any cleanser of any ilk.

Metal scouring pad + baking soda or fine salt.

If you really think you need to, switch to hardware store grade fine wool (likely, you won't need to.)

Rinse with hot water. Heat pan to scalding hot to expand the metal and evaporate all traces of moisture, oil it up, bake in the oven if you want to "set" the seasoning - I usually don't, but feel free.

Voila! Enjoy!
posted by jbenben at 1:12 AM on September 3, 2014 [4 favorites]

Best answer: I'd avoid adding more salt.

If that were my pan, I'd be doing the following things:

1. Unscrew any wooden handles.

2. Give the pan a good scrub with a dishes brush under running hot water, to dissolve away as much residual salt as possible.

3. Rub it thoroughly and completely dry with fresh paper toweling (it will probably stain a tea towel).

4. Bake it in a smoking-hot oven for an hour, then turn off the oven, open the door, and let the pan cool inside the oven.

5. Once it's just cooled enough to handle again, scrub it all over with a steel wool pad soaked in linseed oil.

Repeat steps 3-5 at least 6 times, then again until you're happy with the colour of the resulting seasoning; should take at least 6 repeats. The first round of scrubbing will take off almost all the new rust. Any residual rust will react chemically with the seasoning oil during the bake step, helping to harden it.

6. Rub the pan over with paper towel, reattach wooden pieces and put it away. If it's in a drawer or cupboard rather than hanging from a hook, keep a paper liner under it.
posted by flabdablet at 5:17 AM on September 3, 2014

Flaxseed oil, I think you mean.
posted by dywypi at 6:06 AM on September 3, 2014 [7 favorites]

Do not use linseed oil!
posted by Lesser Shrew at 6:14 AM on September 3, 2014 [1 favorite]

Linseed oil in a can from the hardware shop, bad; flaxseed oil in a bottle from the hippie supermarket, good. (The name given to flax oil in its various preparations varies locally.)

And I've used a scourer, plenty of kitchen roll to dry visible moisture, and an already-hot oven to remove the rest.
posted by holgate at 6:32 AM on September 3, 2014 [1 favorite]

Lemon, sliced in half himspherically, and a bunch of kosher salt. Use the lemon as your scrub brush (also excellent for polishing copper).

Afterwards, rinse and dry well, then reseason with shortening in a 400F oven.
posted by feckless fecal fear mongering at 7:20 AM on September 3, 2014

A brass wire brush with or without a drill will save a lot of scrubbing with salt or other abrasives. Brass is softer than cast iron, so it will remove crud without damaging the iron too much. I've done this several times now with great success.

Flaxseed oil does produce the best, hardest surface I've ever had on a pan, after years of mucking about with other vegetable oils and animal fats. Much better than shortening. It's a deep golden colour, which is kind of neat. Buy the smallest bottle you can---you don't need very much. A base coat of flaxseed oil will thicken and get more durable with repeat use like any other pan seasoning.
posted by bonehead at 8:07 AM on September 3, 2014 [2 favorites]

Steel wool or steel brushes, can damage the pan much more easily than brass. I avoid them on cast iron. Copper scrubbies work ok too if you want to do this by hand, but rotary drill brushes only come in brass.
posted by bonehead at 8:10 AM on September 3, 2014

For removing rust from cast iron cookware, I've always liked the electrolysis method. No elbow grease required.
posted by dcormier at 8:31 AM on September 3, 2014 [2 favorites]

Linseed oil in a can from the hardware shop, bad; flaxseed oil in a bottle from the hippie supermarket, good. (The name given to flax oil in its various preparations varies locally.)

It's the same base oil. The difference is in the processing and storage.

Where I live, "flaxseed oil" is a boutique product obtained at high prices from healthfood stores, and "linseed oil" is dirt cheap and comes from hardware stores. Hardware stores here offer both raw linseed oil and boiled linseed oil. The packaging for boiled linseed oil features prominent warnings about not feeding it to livestock. There is no similar warning on the bottles of raw linseed oil.

I would never season a pan with boiled linseed oil because it contains toxic additives, notably heavy-metal salts that would presumably remain just as toxic at the end of the seasoning process. But I can see no virtue in paying a premium for something cold pressed by barefoot virgins in the moonlight when my intended use for it involves deliberate heating above its smoke point in order to transform it chemically into a tough cross-linked polymer film.

Hardware-store raw linseed oil is probably solvent-extracted and therefore non-ideal for cooking with, but the thing about solvents is they're volatile. I would expect any residual solvent in the extremely thin layer of oil involved in seasoning a pan to evaporate completely within seconds of hitting the hot oven, and I would be astonished to learn that there's any chemical difference at all between the finished coatings resulting from hardware-store raw linseed and healthfood-store flaxseed oils.
posted by flabdablet at 9:02 AM on September 3, 2014 [1 favorite]

Vasoline is a petroleum products that you can safely put on a baby's behind. You cannot put any and all petroleum products on your child's tush. See also - rapeseed oil versus Canola.

If you are in the US, linseed means don't eat this.
posted by Lesser Shrew at 11:38 AM on September 3, 2014

If you have trouble removing any spots, I had good luck using a hobby etching cream (armour etch; I had it around anyone from etching glassware). I dabbed it on with a matchstick end (they were really tiny spots), let it sit for a few minutes (probably 3, definitely not more than 5), then rinsed it thoroughly in water.

After that, I seasoned it in a 350°F oven with a thin coating of lard for 2 hours, let it cool and repeated twice.
posted by carrioncomfort at 12:10 PM on September 3, 2014

I have a decent little collection of cast iron I always make a trip to the local sandblaster when I pick up a rusty pan. A good blaster has a good selection of blasting media on hand and will know the best media to use to get the job done without harming the metal.

My last trip was back in April when I scored a Wagner chicken fryer with lid and both pieces had a fairly good coat of rust. It took the guy about 10-15 minutes shooting the iron with crushed walnut shells to bring it back to near new condition. The total cost was just over 15 USD.
posted by buggzzee23 at 8:13 PM on September 3, 2014 [1 favorite]

I use cast iron frying pans exclusively and nothing ever sticks to them - best pans in the world.

For rust, just use whatever you have to remove it; hot water and dish soap and a plastic or non-scratch pad - whatever works. Rinse thoroughly, dry with a paper towel, put on top of the stove on a burner set at 1 or 2 for about five minutes. I always do the cast iron last when I do dishes and put it on the stove when I've washed it and leave it long enough to do the wiping up counters and refrigerator door and such. The idea is just to dry the pan all the way through the cast iron as opposed to just wiping off the wet spots after washing the pan. Take it off the heat now and wipe the inside and outside of the pan with a paper towel with just a small amount of olive oil or whatever oil you use until the whole pan looks nice and shiny.

Wash the pan using soap if necessary (eventually you won't need soap), rinse, dry with towel, put on burner for a few minutes, remove from heat and wipe out with an oil-dipped paper towel.

After you've been using the pan a lot and doing this each time you use it, you'll find that nothing sticks to it and it's a breeze to clean up.

Hope you enjoy it as much as I've enjoyed mine - wouldn't trade it for anything else.
posted by aryma at 2:49 AM on September 4, 2014 [2 favorites]

Response by poster: Thank you all.

I would love to try @dcormier's electrolysis method, but that involves equipment I don't keep around.

So I'll first try @aryma's method for the simple reason that I already have handy everything needed. If that's not good enough, I'll try @flabdablet's method next but with flaxseed oil.
posted by jshare at 4:34 AM on September 4, 2014

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