Does your Vintage Skillet do this? Or just new Lodge skillets. Black Residue

L

Linn Stevens

New member
I have only owned three pieces of cast iron. All three modern Lodge skillets (6", 8" and 12") purchased this year at Walmart. I'd really like to become better acquainted with the differences in vintage cast iron and Lodge's modern cast iron.

Important back story: I took thorough measure to clean this skillet all in attempt to end the "black stuff" (I chose the 6" of my three Lodge skillets because it was easiest for testing purposes but all three produce the same black residue equally).

I first placed the pictured skillet in a high-end ceramic cooker (Big Green Egg) and baked the skillet at 900-1000F for one hour. After cooling for 3 hours I began scrubbing it and noted this black residue simply wouldn't stop wiping off the skillet.

In further attempt to stop the black residue from coming off I assembled a very capable electrolysis tank almost identical to Jeff's (The Culinary Fanatic). After 20 hours of 20 amp electrolysis the pan looked a little nicer perhaps (not much) but the black residue persisted as ever.

I've not found a clear answer online so I wanted to ask here very simply: What, precisely, is this unending black residue/soot that comes off these modern Lodge skillets?

Is it remnants of Lodge's factory seasoning?
Is it remnants of carbon from my own previous seasoning?
Is it a "flash-iron" similar to "flash-rust" release of the raw iron itself?
Is this what happens on all cast iron pans when you get down to raw iron?

I'm not worried about it and I know a single coat of seasoning will almost completely prevent further release of the the black residue -- I just want to know exactly what the black residue is.

Lodge 6" Skillet after an hour 1000F burn-off and 20 hours of 20 amp electrolysis.
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Just brush and water to remove anything remaining after electrolysis
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First round of Palmolive
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After a good 3 minute scrub you can see the murky colored suds
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Dark suds, still, after a through burn-off and electrolysis?
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Then a round of Comet for kicks; might as well
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The Comet nearly doubled the intensity of the black coloring. Much blacker than the Palmolive suds
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After a good scrub and rinse black residue still coming off on drying cloth
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After first application of seasoning oil black residue still coming off.
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It's just a different form of iron oxide, ferrous oxide. As opposed to what we call rust, ferric oxide. It's what forms when you clean a pan with electrolysis, too. Once the piece is free of crud and red rust, just scour it with Dawn d/w liquid and a S/S brush or scrubber, and rinse. It may never totally stop coming off on your drying towel, but that's OK. Quite normal, in fact. Continuing to scour is probably just creating more "black rust" than it is removing. Just get it totally dry in the oven and then proceed with your initial seasoning.
 
Doug is right....Again...... :roll:

Seasoning will seal all this up and you'll never see it again.

Initially, I'll dry a piece, wipe it down with (whatever oil you're using), put it on the stove and heat it up. Wipe down again with a clean cloth, then re-oil. Heat and wipe again, I do this until the cloth is pretty clean, then it goes into the oven for it's first bake.
 
Thanks so much, Doug! That is a huge help and goes most appreciated. :-) Thank you, too, Rick.

I should have joined this forum a month ago and just asked "what's the black stuff?" before doing 5 different kinds of experiments. I learned a lot, however, and really happy with a new electrolysis set-up for future pieces.

My question now, if I may, is would a 1910's, 20's, Vintage Cast Iron from one of the major brands like Griswold and Wagner oxidize and behave in exactly the same way as my new Lodge skillet?

After a 1000F burn-off and 20 hours of electrolysis I couldn't imagine it was just the factory seasoning or my previous seasoning. I felt it was, as you described, Doug, the iron itself breaking down (oxidizing) on some level at the surface. Thank you, again!
 
Pretty much all of the vintage pieces do this as well. Some more than others, with no pattern that I can discern. I've had Griswolds that came (almost) perfectly clean, and others that were just like you described. Each one has its own quirks and character, that's part of the fun :)
 
John E said:
Each one has its own quirks and character, that's part of the fun :)
Click to expand...

As someone new to cast iron and collecting I believe be recalling that quote for a long time to come! That makes far better sense to me now. Thank you. :)

I guess I assumed (where most all life's errors begin) that the older vintage pans would somehow be of a better quality of iron and, thus, not produce this black oxide but I understand now, that iron is iron and can oxidize in this fashion despite manufacturer or era in which it was made.
 
Depends on whether we're talking removal of build-up or application of seasoning. For the latter, I usually never exceed 500°F, and that's just to darken the iron.
 
The 1000F I did was for burn-off (stripping). 1000F is very common; anytime you use the self-clean function of an oven (among the most popular method of stripping cast iron) you're baking at 1000F and often a little over.

As you know, people also place pans in or just above an open fire which can hit and exceed 1000F. As reference, iron has a melting point of 2800F

I season at 475-500F

Better said: no doubt you can damage a piece with enough heat and exposure time (whether an oven, outdoor cooker or open fire) but I don't believe you're at any risk of damage at 1000 degrees for 1 hour.
 
Look at the wags forum for pictures of fire damaged iron. It isn't pretty. Never strip an antique in an open fire.

Thanks. *wink*

I was informed self cleaning works fine and doesn't damage the iron. I don't trust it, but so many do that I think I'm just paranoid.

I was told YEARS ago, when I was just a kid, to clean it up in the fire (Before internet) So I did. damaged my griswold and warped my big wagner.

just so you know.. please don't use fire.
 
The tell-tale appearance of a cast iron pan that has been overheated/damaged by too-hot fire:

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