Stubborn spots after lye bath

[Alex Zamudio]

Hello all, I am a first time restorer after finding some beautiful pieces in a local thrift store. They were very gunky to the point that I couldn't see the logo on one or handle numbers on the larger two of them. But after 3 days in a lye bath the pans came out and they're a Wagner 3 and 6, and a Griswold 8 which is the real prize.

The gunk just falling off was therapeutic but all three cooking surfaces still have some stubborn spots that are driving me crazy! :D See pictures below.

I put them back in the lye for now, but I wonder if these very thin and stubborn spots are stains, rust, really burnt in gunk and if it's a tool I'm missing or a technique I may have to do in addition to lye. Or am I being too picky? Does it matter at all and do I just season over it?

Appreciate any input. I hope it's not necessary to do electrolysis as my cohabiting situation is not conducive to this.

Thanks!

[Cheryl Watson]

What de-rusting process did you use?

[Alex Zamudio]

I haven't done anything for rust, yet. The composition notebook style markings are from the Wagner 3, while the thin dark spot covering the bottom and going a bit up the side is on the Griswold. The Wagner 6, not pictured, has similar areas on the side to the Griswold. They're just darker and ever so slightly raised.
Thanks!

[Janis Berzins]

I have had slight variations like that that seem to mellow out with the first seasoning. I would say if it is raised it probably needs more time in the lye bath. However, some discoloration does happen even when completely clean.

[Duke Gilleland]

Could be discoloration due to setting in water for a long period of time. Lye does not remove rust, just carbon and other impurities. If just planning to use as "users" these areas will probably blend to one shade of black with extended use

[Alex Zamudio]

Thanks for the input so far! I'll keep the larger two in the lye bath until Sunday, which would be a little over a week. The seasoning/gunk was so thick that these spots were likely encased, possibly for decades by seasoning. If the lye gets to it I'll happily clean it off, but if it's just a thin layer of carbon I'll try to elbow grease it out and then just season over. I may use the small skillet as a test if it's some kind of rust.

Just for background, and I wish I'd taken pictures, I liked that these were so heavily used, though I'm not quite sure how just so much gunk got on the bottom of the large Griswold skillet and would have feared it smoking if I tried to cook with it. The spouts had a bunch of crystalized grease that ran down the sides and even the number on the handle was obscured by the stuff. With all of that said, you could tell that the cooking surfaces were well maintained and I will certainly do the same.

[Alex Zamudio]

Just for the future usefulness of this thread, I wanted to follow up.

The answer to the initial post question was that those spots were indeed very stubborn crud. I ended up leaving the pans in the lye for another 4 days, making it a bit over a week in the solution and upon taking them out they wiped clean.
The crud, which may have been on for half a century or more, revealed a small pit in the cooking surface of the griswold, but nothing major.

Funny thing is I seasoned the pans with oil and they're very spotted, almost looking like rain on a car window, presumably because the oil was too thick and I should have taken out to wipe again 15-20 minutes into the process.

The issue seems nothing but cosmetic though as I've been cooking on the pans with great success over the last few weeks. Have had some sticking issues but I think it's mostly because I'm still figuring out the right temperature to start cooking and have been overheating. I'm using the non-pictured Wagner 6 most so far. At about 8 inches in diameter it's perfect for eggs and moderate sized meals. Cooked a full chicken in the Griswold 8 and it came out perfect. I'm going to enjoy cooking in these more and more over the next decades.

[Russell Ware]

Choice of vintage cast iron must be done carefully. Some people think that a pan that is all thick with old seasoning has been well preserved in that crud. Often times you learn that the bad seasoning and neglect have allowed rust to move in and mar the surfaces of the cast iron. You never really know the condition of a piece until the layers of crud are removed. Be very picky before you throw down the cash.

[Duke Gilleland]

Choice of vintage cast iron must be done carefully. Some people think that a pan that is all thick with old seasoning has been well preserved in that crud. Often times you learn that the bad seasoning and neglect have allowed rust to move in and mar the surfaces of the cast iron. You never really know the condition of a piece until the layers of crud are removed. Be very picky before you throw down the cash.

Situation risky at best. Last week found an OLD Lodge that you could hardly make the letter out on for the carbon. Cleaned up great but a small 3/4" crack near the spout was then detected :'( Win some/loose some :(

[Alex Zamudio]

Thanks. That's excellent advice.
I actually saw an unmarked approx 8" skillet at the same place I bought these last week but decided against it because the size was redundant to my number 6 and because the cooking surface seemed bumpy. The draw to the ones I bought and restored was that the cooking surface was like glass.
I wonder though how that one small pit got into the griswold. Can rust sneak under seasoning?

[Russell Ware]

Can rust sneak under seasoning?

It doesn't really sneak under. More like it has already started, and the user seasons over it. If the piece isn't cleaned and dried properly, that rust starts to spread.
I usually see it on the bottom of a piece that has either been neglected or not maintained properly.

[Cheryl Watson]

I always, always de-rust my pieces after the Lye Bath and before seasoning.  (Lye will NOT remove oxidation.)

Normally I use electrolysis after the lye bath, but I do also have a full arsenal of restoration tools, including a Vinegar Bath and Evaporust. (all for de-rusting and removing carbon black spots that many times DO harbor 'bad' red rust/oxidation underneath). 

[Jeff Friend]

Alex,

That small pit you mention could be a defect in the casting and not the result of rust.  It could be a sand hole that was deep enough that it would not be removed when the surface was ground smooth.  Post a picture and maybe we can tell.

Keep in mind that hollowware was mass produced and quality control wasn't always too good back then.  There is no way to prove it, but I would bet that a fair number of pieces left the foundry with small cracks.  For example, I have a skillet where there is a crack right at the spot where the man grinding off the gate jammed the skillet into the wheel, leaving a deep grind mark and a crack.

Jeff

[Valerie Johnson]

There is no way to prove it, but I would bet that a fair number of pieces left the foundry with small cracks. 

I also believe that, While maybe not so much in cast iron I have noticed it quite a bit in pottery, Usually in pottery the cracks that occur over time/use are straighter and the ones that are factory imperfections are more zig zag for lack of another word and my guess is that if it occurred in pottery then it also occurred in cast iron, In pottery we see a lot of pieces that are supposed to be round that are misformed, I would also venture to guess that some cast iron pieces that have wobble may also have slipped by quality control.

I think that once they went from hand made to machine made that quality control slipped quite a bit.

[Jonathan Sutton]

Something else to keep in mind is that we have a survivor's bias with the extant vintage hollowware. Most or all of the really poor quality vintage cast iron has long since been scrapped. It would not surprise me if even the better-known foundries (e.g., Griswold and Wagner) turned out their share of lower grade stuff, but the lower grade pieces simply did not survive the rigors of being used every day.

[Cheryl Watson]

Huh?...
I don't agree..
But that's me. :)