Personally I would be careful about sandblasting cast iron. Some of your finer older cast iron have polished cooking area. Sandblasting will damage this area. Here is what I do when I get rusty cast iron. I have a 55 gallon barrel about half full of lye water. I put my cast iron inside it, and leave it for about 7-10 days. When you take it out, the black built up crud will wash off. If not, scrub it a little and put it back in the lye barrel. It will all come off eventually. This leaves the rust, after being in the lye barrel, the rust comes off with the crud. Then take the skillet in the house and wash it in blue Dawn dish detergent in water as hot as you can stand it. Wash, and rinse in cold water. Repeat this until the skillet does not "bead" up. You might want to hit it with a brillo soap pad during this process if you have some tough rust. Now this is a important part. As soon as you rinse in cold water, place it in a oven at 225degrees for 20 minutes. If you don't it will "flash rust" in front of your eyes. After 20 minutes, take it out spray it down with original Pam seasoning as if you are spray painting. Wipe the excess out with paper towels, don't scrub just wipe out. Then put back in oven at 375 degrees for 20 minutes, and after that crank the oven up to 500 degrees for 20 minutes. Take the cast iron out, spray it with Pam again like spray painting, then leave it along for about five minutes. Wipe the excess down as the cast iron cools, when its completely cool, wipe the cast iron down and you are ready to go. This Pam method works way better than the second best method, Crisco shortening, only Crisco. This cast iron comes out black, slick and ready to cook in. To keep it like this, never use dish detergent on it again. After using it, wipe it out with hot tap water, as hot as you can stand it. then put in on a stove eye for a few minutes until it starts smoking a little bit. Then spray Pam in it, let it cool and wipe it down. You will throw all your teflon pans out if you do your cast iron this way. I have some cast iron that was made in the late 1800's I cook in. If you want quality cast iron, the older the better.
Here is a piece I just got seasoned this past week. An old #8 bean pot with lid.

I guess I should say, if you are not going to cook in it, just use a wire brush on a drill, clean the rust out and wipe it down with mineral oil. This will make it look good. And if you decide to cook with it later, hot water and dish detergent will take the mineral oil out and then season it with Pam.



Here are some cast iron I bought today. Most of these pieces are nearly a hundred years old.

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