Not long ago we talked about where to find cast iron at a reasonable price. As we discussed, sometimes getting that deal means picking up a piece that's less than show room quality. So how do we get that rusty gold looking new? Well, it should be said up front that it didn't get this way overnight, so it stands to reason that its not going to get cleaned up in quick fashion either. The other important thing to remember is that no amount of cleaning and re seasoning can cure severe pitting. Now with that in mind, lets roll up our sleeves and get to work.
1)Get it HOT!!!
There's two options here. The first is to build a nice fire, pitch the iron in and leave it be for a while. Let that cast get good and hot. The fire will help to burn away and loosen much of the surface rust. A caution about this method; antique cast iron tends to be much thinner walled than modern cast iron. This amount of heat COULD cause older cast iron to warp or possibly even crack. If you are working on old iron, this may not be a safe method.
The other option is to put the piece in a modern oven on self-clean mode. This method is much less likely to cause the warping and cracking issues with older iron.
Now that we've got that surface rust burned up and loosened, time to grab the ole' wire brush and go to town. This works best when the iron is still pretty warm so make sure you've got a good pair of leather gloves on hand ( pun intended). Give the cast a good wire brushing all over to get all that rust cleaned off the surface. A wire wheel attached to a drill may make this job a little easier.
3)Time to Exfoliate!
OK, we aren't really exfoliating, but salt scrubs aren't just for fancy spas anymore. Pour some salt into your piece, and scrub away. This can be done with a sponge, but if you can get your hands on a piece of harness leather this works even better. The salt scrub offers two benefits. The first is that salt is a good natural abrasive and will help to further buff any remaining surface rust away. The other, and at this point perhaps more important benefit is that the salt will help to draw the rust out of the pores in the iron. Remember, it didn't get this way over night so this is going to take several times repeating this step. Scrub, rinse with hot water, rewarm the piece (it doesn't have to be burning hot, just good and warm to open the pores) then start the process again.
4) Baking Soda and Vinegar
If, after several salt scrubs, you are still getting rust from the pores, try pouring some baking soda and vinegar in the piece. The chemical reaction will help to eat away at any remaining rust deep in the pores.
5)Oil Her Up
Once you've done all of the steps above and you are fairly certain that you have removed as much rust as possible, heat your iron up to a nice warm temperature again. Now, using a lint free rag, wipe the piece down with oil. I prefer to use olive oil due to its resistance to turning rancid over time, You will probably find that you still get a little rust color on the rag. That's OK, Rinse it with HOT water, and do it again.
With some patience and elbow grease you will eventually end up with a piece of cast that will make a great addition to your collection. Now all that is left is to season it (a topic for a later blog) and put it to good use.
A WORD OF CAUTION!!!!
There is a method out there where people are spraying their cast iron with oven cleaner, putting it in a bag for a few days and then cleaning it. I ABSOLUTELY DO NOT ENDORSE THIS METHOD! Remember those pores and all that pesky rust they absorbed? Well they absorb other things also, including chemicals. If you wouldnt eat it, why would you want it soaked into the pores of your iron.
So thats it, really nothing to it. Get out there, find that rusty gold and start adding to your collection! Good luck. If you have any questions, ask away. I will give you the best answers I can.