Other methods follow John Belden's method.
Cleaning Cast Iron Using the Lye Method and Self Cleaning Oven
How do I clean cast iron? (This article is followed by an untraditional method of cleaning using a self-cleaning oven--be sure to read the article by Jack Hinkle that follows this one).
Cleaning Iron With Japanning by Tom Neitzel follows Jack Hinkle's article. All good information!
Lye is the preferred chemical for cleaning cast iron. Lye such as Red Devil can be used to make a lye wash for larger projects or lye-based oven cleaner can be used on smaller jobs. It is becoming more difficult to locate lye in hardware or grocery stores in the toilet bowl cleaning section because of the increased use of this household product in illegal meth-making labs. So you may have to do a lot of searching to locate it now.
Be advised however that during use, this lye wash is quite caustic and must be used with respect.
Because of the violent chemical reaction that could occur, extreme caution must be exercised when mixing the lye wash. It is imperative the lye be added to the water not water poured onto the lye. Water poured onto lye can cause a violent chemical reaction and the wash could "boil-up" into your eyes or face.
As a precautionary measure, a clean water source should be immediately available. If the solution feels "soapy", the solution is in good working condition, however, if the solution comes in contact with the eyes or skin, it must be washed off immediately. Always protect your eyes as the solution could cause permanent damage if contact is made with the eyes and not immediately washed out. Vinegar can also be used as a neutralizing agent.
Always keep the solution away from children.
It is probably best to always keep the container covered. This will prevent evaporation, minimize the chances of spills, and protect against foreign objects from falling into the vat.
The lye wash can be used for more than one "batch" of cleaning.
The following instructions must be used with caution and at your own risk.
Lye Wash Method:
Step 1
Soak cast iron pieces in lye water. Mix 1 can of lye (i.e., Red Devil) with 4-5 gallons of water in a plastic or stainless steel container. Suspend pieces utilizing steel coat hangers or heavy wire.
Step 2
Remove pieces after soaking and rinse with hose and relatively high water pressure. If grease, paint, etc. does not wash away, try wiping with stainless steel scouring pad or brush. Repeat Step 1 as required.
Step 3
After piece(s) are dry, brush with fine steel brush on drill or wire wheel. Do not use a brass brush, as it will discolor the iron.
Step 4
Wipe piece(s) thoroughly.
Step 5
Apply mineral oil, generously, with small paintbrush--make sure to completely coat items. Let stand overnight.
Step 6
Wipe off excess oil with paper towel.
Step 7
Polish with soft cloth (flannel recommended). This step is very important to provide non-sticky cast iron.
Rust conditions - If steps 1-3 do not remove rust, do the following:
Step 8
Soak pieces in solution of 50% white vinegar and 50% water for maximum of 24 hours.
Step 9
Remove from vinegar solution, rinse and rub/brush to determine if rust has been removed. Repeat Step 8 as required. Do not leave pieces in vinegar solution for an extended period of time as damage to the piece(s) may result.
Step 10
Repeat steps 3 through 7.
Follow appropriate safety precautions as required (rubber gloves, welder type gloves, face shields).
Easy Method:
Step 1
Apply oven cleaner such as Easy Off or Mr. Muscle.
Step 2
Place the item in a plastic garbage bag overnight (the bag keeps the oven cleaner from drying out).
Step 3
Rinse off.
Step 4
Repeat the process if necessary.
Step 5
Scrub with a brass pot brush.
This page is courtesy of gcica.org member
NOW FOR A DIFFERENT METHOD
USING A SELF-CLEANING OVEN FOLLOWS:
CLEANING IRON COOKWARE USING A SELF-CLEANING OVEN
BY JACK HINKLE hyjack@bresnan.net
Recently, Hanford Miller of CO called with a good question: "Is it safe to clean iron using a self-cleaning oven?" He had just come from a vendor who had a pile of iron that looked like it just came out of the mold, brand-new looking. She told him she cleaned all her iron with a self cleaning oven. He was impressed with her results.
Hanford went home and tried to clean a really crusty #6 skillet. It came out beautifully clean, but had a crack. He admits that the crack could very well have been there under all the crud, but before he went any further, he decided to ask.
I knew from talking to other members that aluminum pieces with all the wood parts removed did extremely well and came out very clean using this method, but I had no information (first hand or otherwise) about how it would work with cast iron. So, I placed a couple calls.
John Toomb of WA was my first call. Like me, he still uses the lye method to clean, but had a bit of experience with self-cleaning ovens and iron. Because the oven gets VERY hot, the manufacturer of the oven tells you to remove the racks, but if you do, you can't do the iron, so John figures it's worth any damage it does to the racks by leaving them in. John's best advice was this. "Call Jack Hinkle of MT. He has a lot of experience with it."
That was a super lead. Jack has cleaned successfully over 500 Griswold pieces and 150+ Wagner Ware pieces in his self-cleaning oven. He bought himself a used oven to put in his workshop so finishing is handy with all his tools right there.
Look at these before and after photographs of a #90 by Jack: Dirty & Cleaned:


BEFORE--UGLY DIRTY PAN--both sides a mess
AFTER--WOW--same pan cleaned
BEFORE CLEANING AFTER CLEANING
Jack has the following tips to pass along to you:
CLEANING IRON COOKWARE
1) Load both racks with 4 or 5 pieces each, what ever will fit, with out cramming them together. They can touch but without pressure and stacking .The object is to heat them evenly and leave room to expand and flake off the gunk ash.
2) For Dutch ovens, skillets, scotch bowls, etc., place face down (upside down) and flat. This allows the ashed residue to fall free. Sometimes a drip from the rack above will land on a piece under it and leave a mark. This way, you avoid marks on the presentation surface of your showpiece.
3) Handled Griddles: place face down and flat, by inserting the handle through the rack.
4) Jack usually sets the self-cleaning cycle for about one and a half hours; for extremely dirty iron, two hours will be plenty of time. When he tried less, he didn't feel it quite did the job.
5) The instructions with most stoves say to remove the racks, but you need them and it will eventually discolor them but this is all Jack uses this oven for.
6) He only did this once (see #5 above) in his wife's oven in the house. It set off the smoke alarm and stunk up the house for a couple of days. If you are using your home oven, try it with only one or two pieces at a time.
7) The oven will automatically lock at a certain temperature as it goes through its cycle. When the unlock signal indicates that the cycle is completed, the temperature is usually 200 degrees F.
8) Allow the oven to continue to cool down another one hour or so, as it is still too hot to comfortably handle and brush the ironware.
ALWAYS HAVE LOTS OF THINGS TO KEEP YOU SAFE WHILE WORKING-SAFETY BEGINS AT HOME. HERE'S A PHOTO OF JACK'S SAFETY GEAR, FACE SHIELD, EAR PLUGS, GLOVES, RESPIRATOR:

After having removed the iron from the oven, brush off the ashes.
Use gloves to pick up the iron as it is still quite warm and use an old rag to wipe of the loose dust. Be careful not to bang it around as it may still be fragile until completely cooled. The iron will finish better and easier while it is still warm.
Basically, three tools are needed for finishing:
A) 4" Angle Grinder with a wire cup brush:

Note: Use this primarily on the inside and outside bottom of flat pieces, (skilllets, Dutch ovens, etc.) Buff with a circular motion in the direction that Griswold originally ground them.
B) a Bench Grinder with 6-8" wire wheel; larger will work fine:


Note: This tool works well on the rounded places, and ones that you need both hands to hold the iron piece.
C) Drill Press with 3-4 different size wire wheels and small cup brushes:


Note: This works real well for things like muffin pans with round holes, then the different diameter brushes get a work out. The small flat wheels works well on the basting rings of lids. If possible, use stainless steel wire wheels. They are softer than the cast iron item, so less likely to scratch it. Let the tool do the work, using fairly light pressure.
(Hanford Miller, another member of our club, comments: Don't overlook the application of air tools for this work. Both straight and angle die grinders may be even more handy for this project. This may be your opportunity to get that air compressor you've always wanted! )
Two Solutions for Seasoning Iron Cookware
For use in cooking:
1) Place iron in oven at room temperature.
2) Set oven at 300 degrees; turn on for 2 hours.
3) Lower temperature to 200 degrees for 1 hour.
4) And wipe out with peanut oil, turning up side down on newspaper to cool, after cooling finish by wiping off excess oil.
5) Now you are ready to cook in them and really finish the seasoning process over the next couple years.
For use as display pieces:
1) Put in oven and set to 200 degrees for ½ to1 hour.
2) Turn to 100 degrees for 1 hour
3) Remove from oven; wipe out with mineral oil. Place on newspaper to cool. Wipe dry after cool to touch. This makes a nice, non-sticky surface to display or sell while protecting the iron from rust.
(A comment from H.J. Miller, another member of our club follows: The reason for the lower temperature cooling step in seasoning and cleaning is to avoid thermal shock to the iron. Either cooling process could be accomplished by turning off the heat and allowing the oven to return to room temperature without opening the door.)
Another result of the transformation from Self-Cleaning Oven Cleaning for a #10 deep skillet, small logo Griswold by Jack Hinkle:

Dirty (above) then clean (below)

(Below--dirty 10 inside and then clean 10 inside):

For questions or suggestions, contact Jack Hinkle, 1210 Fourth Street, Deer Lodge, MT 59722-1516 or email hyjack@bresnan.net
The following blog has been written by Sheryl, who has given permission to post her method of cleaning and using cast iron cookware. Check out her work at: http://sherylcanter.com/wordpress/2010/01/perfect-popovers-and-how-to-clean-reseason-cast-iron/ perfect-popovers-and-how-to-clean-reseason-cast-iron
CLEANING IRON WITH JAPANNING BY TOM NEITZEL
How Do I Clean A Japanned Finish?
By Tom Neitzel

What is a japanned finish? It’s a black, tough, durable asphaltum based finish that was put on parts to simulate the very fine Japanese lacquered look and prevent rust. It’s a pretty nasty concoction of chemicals - turpentine, boiled linseed oil or spar varnish, and asphaltum.
I don’t specialize in collecting waffle irons, except for Alfred Andresen and Western Importing products, but I will pick any up that interest me. I’ve picked up a couple of aluminum irons that have had cast iron bases with beautiful japanning.
I’d always wanted one of the E.C. Simmons Keen Kutter waffle irons with the name part of the finished waffle. They’ve always been pretty pricey around here (Western Washington State). I finally ran across one on eBay that was priced decent and a high base so I grabbed it. It was in good shape, nicely seasoned, but I like to clean them up and leave it pretty much natural with a coating of mineral oil.
As I looked at it I found what looked like japanning under the handles. You can see it in one of the pictures (taken after I had removed most of the seasoning). I didn’t believe it was seasoning because it is so even, tough and under the handle. I thought that the base might be japanned and wanted to preserve as much of it as I could.
I didn’t have a clue as to cleaning and preserving the finish so I posted a note on a couple Forums. I didn’t really find anyone with much information other than possibly treat it like paint, although it is a bit tougher than paint.
I decided to try Dawn Power Dissolver. That’s been good at removing some caked on seasoning from aluminum. It did remove a lot of the seasoning, but not all. I then decided to use a pretty concentrated solution of household cleaning ammonia, another grease (seasoning) cutter. This removed all but the most carbonized seasoning and left the japanning untouched. I was disappointed as it showed me that about all the japanning that was left was the little bits under the handles. The black on the sides of the base was pretty much seasoning.
On the following pages are some before pictures. The base has been through a Dawn Power Dissolver and ammonia cleaning. The paddles were not japanned so they’ve been through a day in the lye tank.
Since there was so little japanning on the piece I decided to strip it all off. I like to use a self-cleaning oven to clean (a 3 hour cycle), making sure to take off any non-cast iron parts so they are not damaged. The rods that the handles go over are steel and pressed into the casting so I could not remove. What will happen to steel is that it will darken and discolor in the heat.
After the oven cleaning, I put the base in the electro tank to remove the very light rust. The paddles and coil handles were put in an Evapo-Rust solution for rust removal. I’ve been experimenting with Evapo-Rust and like it – works like magic in a few hours but is expensive. Removes rust and leaves the surface clean – no scrubbing which is nice for the inside of a waffle iron. The Evapo-Rust also removed the darkening of the steel rods, restoring them to a natural look. You can find it at Autozone and other autoparts stores, and on the web.
I coated the parts with mineral oil, soaked then wiped off, put the handles back on and have an iron I like. There are some after pictures here too.
Am I an expert on cleaning japanned pieces? No, but I do have some suggestions. Treat it like a painted surface. Assume that prolonged lye soaking will remove it. It was suggested that I could soak it quickly in lye, time measured in minutes then rinsed off. I think that would work, but don’t leave it or forget it. (I actually have cleaned aluminum that way without damage.). Try cleaners that are meant for home that cut grease like Dawn Power Dissolver and ammonia. I don’t know what electro would do to it – asphaltum is an insulator so it might not harm it as long as it is not scratched or chipped.
I’ve ended up with a waffle iron I wanted and like. Learned a bit about finishes and cleaning. There is a commercial source for an authentic japanned finish if you want to try restoring a piece, www.libertyonthehudson.com.

In the next picture I show the whole iron just for reference. Remember, I've just started to clean it. I've removed the handles and it has been one trip in the lye (paddles only). The rust is just from getting rinsed off. The casting looks like it just came out of the mold.

I'm tired of the lye, so next into the self-cleaning oven.
Below another picture of the Keen Kutter Base. This time it is partially cleaned. Enough to see that what little japanning that is left is not worth saving –it’s just around the bottom rim and under the handles.


Tom can be reached (P.S.T.) at 360-446-1286 or email him at tomn@fairpoint.net.
If any of you have some good suggestions about the care, cleaning, storage, or displaying of iron,
please contact me with information at dmosier1@zoominternet.net or write to Doris Mosier,
17424 Jordan Drive, Saegertown, PA 16433. Keep deadlines in mind, always at the top of the
current issue of the newsletter. The members love to hear about how other collectors go about
it.
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