Cast Iron Restoration

dlee56

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I bought this cast iron skillet (Griswold small logo ~1940ish) off ebay for $20 because these old skillets are thinner, lighter and a hell of a lot more smooth than today's from Lodge, etc. but the cooking surface on this one had some sharp spots and issues from the previous owner seasoning it incorrectly so I decided to do a full restoration.

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I want this to be my breakfast/egg pan so I needed to restore the perfect smooth cooking surface that these old Griswold’s are known for to get that slick non-stick effect. So I built my own electrolysis tank to strip the skillet down to the bare iron so I could then re-season it and make this 80yo skillet like new.

Electrolysis tank:
  • 5gal bucket (this is a small skillet so a larger skillet may need a bigger container)
  • Scrap steel bar (anything somewhat clean, just no stainless)
  • Copper wire thick gauge
  • Steel wire
  • A piece of scrap lumber
  • Washing soda (sodium carbonate)
  • A 12v battery charger (older the better)
You can use your imagination here but the key elements are to have the positive from your battery charger clipped onto the copper wire which is in contact with the steel scrap, spaced evenly around your tank. It’s important to keep the copper out of the solution so you don’t get the copper degrading and turning your skillet green. Then you want the negative from your battery charger attached to the steel wire, which acts as the hook you hang your skillet from, the wire is attached to the scrap lumber to keep your skillet suspended in the center of the tank. Lastly, fill the tank up with water and dissolve in approx. 1TBSP of washing soda per gallon of water. Plug in your battery charger and the whole thing should fizz up with bubbles if its working correctly.
Here is a photo of my setup for a general idea.
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My old battery charger struggled to give it the full amperage consistently and hovered around 2-4amps most of the time. I think this is why it ended up taking the better part of 24-36hrs in the tank to strip all the old residue off. After it was done in the tank, it took some elbow grease, steel wool, and some scrub pads to clean off every flake of residue that was stuck in any scratches or dimples.

At that point I had my bare iron pan and it was time to re-season it. If you’ve never seasoned cast iron before it’s a pretty simple process, just take a high temp fat or oil (I used a pre-mixed seasoning compound which consists of beeswax and grape seed oil), use a rag to wipe the oil all over the pan even the handle and bottom, you want the hole thing covered. Then use a clean rag to wipe away all the excess oil, this is a crucial step because if you leave too much oil on the pan you’ll get a lumpy and sharp seasoned surface which is what made me start this restoration in the first place. Then throw your BBQ grill on high and set the skillet in there for 20-30 min and you should have a layer of seasoning locked in. When seasoned properly the skillet should be smooth and feel polished, if there’s any sticky or oily spots at all keep it in the grill another 20 min or until the sticky spot is smooth to the touch. Repeat this process 4x for a solid foundational season and then your all set to use the pan! Additional seasoning via regular use always helps keep the skillet in good shape, but doing a full season every month or so never hurts. Below you can see the progression from bare iron to fully seasoned, that bronze color is a good indicator of a solid foundation on your cast iron.
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Final product is just as nonstick as my expensive coated pans. Here is my first attempt at a fried egg, over easy, no crust, just how my I like it.
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Has anyone else restored some cast iron with electrolysis? Or is there a better way you know of? I'm also curious to see if anyone has previous experience with electrolysis that can help improve and troubleshoot my system as I start to build a bigger tank for larger skillets?

Thanks for reading!
 

92xj

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I've done a lot of cast iron the easy way. Place in oven, place something on the rack below that can't burn to catch stuff. I am not sure if tin foil holds up, I use an old cookie sheet that the wife doesn't use anymore. Whatever you use, be aware it will be burned to perfect cleaness. Set oven to self clean and let er rip. After that is done, the cast iron will be as clean and clear of anything to anyone's standards. Then on cheap stuff, I use a grinder and polish the inside to my smoothness liking, season after that however you normally do. They have all come out as great and the process is super simple. Do it in the winter time to help heat the house.
 

Matt Cashell

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I love vintage cast iron. That Griswold looks great.

Like 92xj said, The easiest way to clean all the old seasoning off is to just put the pan in a “self-clean” oven and run the clean cycle. The pan will come out looking like it came out of the electrolysis bath. Right down to the bare iron.

I like seasoning with avocado oil. The more thin layers, the better.
 
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Looks like a very good job cleaning up to start over. I've cured many of cast irons to a non stick. I use potato SKINS AND ROCK SALT. Cook it until pan changes colors cool down slowly clean up with paper towels and crisco, not vegetable oil. Place upside down in oven on low heat for about an hour or how ever long u want. Repeat pan will get better as you cook on it, I only use hot water to clean then crisco to put on it. Never just oil until . U can cook with vegetable oil don't use olive oil or light oils that burn easy until you get the season you want on the pan. There are many ways to cure all work well this is just how I do
Electrolysis is the best way to clean vintage iron with a lye bath coming a close second

Heat based methods can damage the iron or cause fires and power tools will damage it, possibly to a point where it won't take seasoning but definitely to a point where it's lost any value
 

NRA4LIFE

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Electrolysis is the best way to clean vintage iron with a lye bath coming a close second

Heat based methods can damage the iron or cause fires and power tools will damage it, possibly to a point where it won't take seasoning but definitely to a point where it's lost any value
What if it had no value to start with? This is what I am referring to.
 
OP
dlee56

dlee56

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These things are cast from molten iron. How do you figure a grill or oven might "damage the iron?"
In the oven for cooking or seasoning is fine but the ovens self clean cycle can get up to 900-1000deg, and that can sometimes warp the bottom making it wobble and spin instead of sitting flat on the cook surface which can make a vintage pan worthless. Sometimes it can also cause a crack of its cooled down too fast from those super high temps.
 

Jpsmith1

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These things are cast from molten iron. How do you figure a grill or oven might "damage the iron?"
I've seen them heated to a point where they turn a permanent red color and will no longer take a seasoning.

I've seen them cracked or warped from uneven heating.

Yes, they're very durable but they can be damaged by careless heating
 

Jpsmith1

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What if it had no value to start with? This is what I am referring to.
As far as pieces with "no value" there's no reason not to get creative with them

I get a little touchy. I found a Griswold Slant logo #13 for a really nice price. Figured I could make enough to buy a decent rifle with the profit.

Someone has taken a grinder to it. Wound up turning a pan that could have brought $2000 into a hunk of scrap metal.
 

Matt Cashell

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If you're curious.

That article refers to fire damaged cast iron. Those temps are over 2000 deg. F.

A self-clean oven cycle temp is around 900 deg. F.

I have used this technique probably 50 times on vintage pans without issue. Of course, you need to let the clean pan cool gradually by just leaving it in the oven. Rapid cooling even from cooking temps could be detrimental to the integrity of the pan.

I wouldn’t risk mechanical methods like a grinder on a vintage pan.

Electrolysis certainly works too, just more hassle.
 

Jpsmith1

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That article refers to fire damaged cast iron. Those temps are over 2000 deg. F.

A self-clean oven cycle temp is around 900 deg. F.

I have used this technique probably 50 times on vintage pans without issue. Of course, you need to let the clean pan cool gradually by just leaving it in the oven. Rapid cooling even from cooking temps could be detrimental to the integrity of the pan.

I wouldn’t risk mechanical methods like a grinder on a vintage pan.

Electrolysis certainly works too, just more hassle.
I restore iron as a side gig. Got a 55 gallon drum and a big garage charger setup.

No hassle but I get it for single pan restorations. I usually recommend yellow cap EZ off and a trash bag.
 

Harvey_NW

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A palm sander can be your best friend.
@Jpsmith1 I noticed you had a negative reaction to this, curious as to why?

For what it's worth, I was a metal fabricator by trade for almost a decade so I could understand how someone without experience damaging their pan might irk you. But I have a couple cheap Lodge casts I was considering sanding smooth and reseasoning. Is there a logical reasoning why not to, or just a personal preference?
 
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