First thing, this isn't a hard project. This process isn't a one hour project. When finished you will have a piece of cookware that you will love, and wonder why you ever spent the money on a new high cost cast iron pan..
Step 1: Disclaimer - Tools Needed
There is a market for old cast iron. Please do not do this on something that you could actually get financial value if sold to a collector. Old cast iron is beautiful stuff and I don't want you wrecking that on my shoulders. In the end this is Cast Iron, but in sentimental value, older pieces have much more cooking time on them and their age/manufacturer does contribute to its overall worth. My advice is this process is for those pieces that are inexpensive ($40), made in the past 20 years, and have a rough cooking surface after an oven clean cycle. You are going to grind metal off the pan and then polish it. If you are not good with power tools, this project is not for you.
Note: You will get someone in your social circles that will say you have just ruined the skillet, and in every practical way you have changed the way it was designed to cook. This project is not recommended by the mainstream cast iron community. Infact if you ask manufacturers, connoisseurs, or regular cast iron cooks they will say just continue to cook with it, season the skillet and time will make the skillet better. Which is technically correct.
This is an easy project if you enjoy sanding, and oiling your work. You will get out what you put into the skillet. If you take a look at the photo above, this Wagner Ware skillet is not in the best shape but it is older than the cast iron I will be working on (Made after 1959). Pay attention to the inside surface. It is smooth and looks as if a large grinding wheel was placed on the inside. I didn't do this, someone at the plant did.
Step 2: Your Cast Iron Skillet
I need to make this as clear as possible. DO NOT DO THIS TO CAST IRON THAT IS WORTH MORE THAN AN AVERAGE LODGE 12" SKILLET.
This project is for iron that is just so rough and worthless, no one even after it was seasoned 5 or 10 times would consider it worth the trouble to cook on.
The picture above shows the skillet I chose to sand and polish. My first shots didn't save properly, but this iron was rusted and rough before I tried scrubbing it. After my first seasoning, this is what I had to work with. Not bad and comparable to what you can buy today from Lodge at Costco.
Step 3: My Video of the Project
I encourage you to read this instructable, however watching what I did will be much more effective, than perhaps the available pictures that I have.
View it here:
Step 4: The Mount - Simple and Effective
The mounting bracket is found in my video at 1:51
I had access to some rough cut thick planks of wood. I bought a long eye bolt, cut the eye to be a hook and I mounted it to one side of the wood. Then I marked the other side. Drilled a channel for the long bolt and made it adjustable to the cast iron I would be grinding.
The bracket was designed to be held in place by my table vise. It was solid and to make it even better I supported the other side with a 2x4 so it rests on the counter-top.
Afterwards, this will be used for fire wood or a replacement landing for my compost entrance. Either way the wood bracket will be re-purposed.
Step 5: Avanti Pro Quick Strip Disc/Sanding Pads
I found all of this at home depot. I can't tell you much. The company has a really worthless website, and I could only find it at one of the big box stores.
I used this for the initial stripping of the iron surface. It worked quite well, but I am glad I moved on the the sanding discs later. If I had to do it again I would have borrowed a more sturdy and powerful drill to mount the scrapper.
These pads worked well Diablo makes a circular sanding pad and a circular foam drill insert for the pad to stick the sandpaper to. They were not fun taking them off when the surface was spent, but they worked. Make sure to get more of the rougher pads and maybe even another mounting pad. Depending how much surface you want to remove, the rough pads do the job quickly
Step 6: 40 Grit
The level of grit is going to get the most product off the surface. Looking back I wish I had bought more if these. I only had two pads and when I was done I could have doubled them and never reconsidered the choice. I didn't push hard and I moved around the surface in even movements. In no time the once black surface was now a dull but vibrant silver colour.
Step 7: 80 Grit
While this level of grit did take the surface down even more, it wasn't nearly as effective as the 40 grit. At the time I was extremely happy with my current progress, so I wasn't thinking I should just stop and go get some more 40 grit.
The griddle was problematic in that the grills were not a lot of surface area but they chewed the pads up quickly. there was no way to get in between the grills so I just left it. Turns out the griddle was not my most valued piece at this stage.
Step 8: 120 Grit
You are going to start considering 120 your pre-polish stage. The silver color can now reflect light and the groves left by the grit is starting to make the skillets pop. At this point I am not sure if going further will help or hurt the seasoning process.
Step 9: 220 Grit
By the time I was finished with 220, I was in full grin. I wasn't sure how they would season, but I had smooth shiny skillets that a few hours ago were a rough mess.
Step 10: Wash/Scrub/Rinse/Dry
After I patted myself on the back, I took the iron back to the house for a scrub in the sink with soap and steel wool. I patted the skillets dry and popped them into a 200 degree F oven to dry off completely. The square skillet has some flash rust develop, but it was easily wiped off with a rag.
I was ready to season.
Step 11: Seasoning the Iron
The first season was more about corrosion protection then anything else. It was late in the day and I had been planning on seasoning two times after work for three days. I used a process shown here . I used lard, and followed the instructions always allowing the oven to cool on its own. My advice is don't rush it, and don't worry, seasoning isn't about how it looks in the end. It is about how it protects the surface, protection from corrosion, and offers non-stick cooking through baking the oil into a plastic like surface. The patina is only a small fraction of the reason for seasoning a pan.
While I was happy with the overall results, I was concerned that the pan wasn't browning like I expected. Instead of the blackening, I was getting a yellowing on the silver surface. The 2nd and 3rd did a great job filling the minor dimples left by the sanding process. The yellow/browning continued as the 4th and 5th cycle completed. I stopped with the griddle. and made room for some other cast iron to enjoy the final oven seasoning process.
UPDATE: After reading a few articles on seasoning, I think I know why my pan isn't going black. My lard has a high smoke point, and the carbon in the oil isn't smoking causing the blackening. The oil is plasticized and even though it is golden, the skillets are seasoned.
You have the whole oven, so use it! Don't just season one piece, fill the oven up with as much iron as the shelves will allow.
Step 12: Maintenance of Cast Iron
There are many ways to clean skillets. When I use soap, it is because all other efforts have failed.
Before using soap, get yourself a good plastic scraper, large grain salt, and a plastic scour pad. Steel wool is an option, but try the first items as you don't want to scratch the seasoning off.
Use these methods for cleaning and remember to lightly coat the iron with oil when done. Plenty of videos on YouTube that can help you on the maintenance.
Step 13: What I Learned You Should Also Do...
Take your time, and get more 40 grit pads than you think you will need. Most of the surface issues will come out faster with a 40 grit pad than if you jump to 80 grit. After that 120/220 pads will at best polish your pans smoothed surface.
Wear a face mask. I have recovered now that I finished the project. For a few days afterwards I had cast iron dust in my eyes, my mouth, and nose. My lungs were not happy with my decision to go without a mask. The black mucus I was blowing out of my nose never seemed to stop. Also the taste of cast iron lingered for days.
If you own a version of the Neti Pot, use it after the project just to clean out the sinuses.