I found three, extremely dirty, cast iron pans yesterday. Two are "Lodge" brand. The largest, is of unknown origin. All three are larger than my other cast pans.
They came from a rat infested house, that hasn't been clean for many years. Residue from several meals sat in the pans for months, growing mould. The sides and bottom were greasy. A very icky mess.
After the greasy rotted slime was washed off, they went into the
oven for two hours. The exhaust fan dealt with smoke and stink.
After they came out of the oven,
I gave them another very vigorous scouring with stainless steel wool and a 1 inch wide putty knife. I continued to scour the pans for about 15 minutes. This removed an amazing amount of debris, and left the
water black.
After they were sufficiently smooth, I dried them with a towel and put them back into the oven to further dry.
A coat of vegetable oil was applied. Not too thick on the bottom and sides.
The oily pans went back into the oven and roasted at 250 degrees for two hours. I went to bed and let them cool.
They look almost new now. There is nothing to indicate that they have been horribly abused.
Total work, including hauling them out of the house and scraping with a chunk of scrap iron at the jobsite, was about 90 minutes. I have good equipment, (steel wool and a steel putty knife) and I treated it like a an athletic event.
Considering the cost of this quality of big cast pans, I think it was time well spent.
Paul and Jocelyn made a
video on the subject a few years ago. I was tired, after a hard day
scrounging, so there was no time for video finding or watching.
https://permies.com/t/52129/Dale-cast-iron-pan-refurbishing