3 pcs. 3/8 inch or 3/16 inch or 1/2 inch stainless steel rod 36 inches or 48 inched long
2 pcs. 3/4 inch wide or 1 inch wide by 1/4 or 3/16 inch thick by 5 inchs long stainless steel flat bar stock
2 1/4 x 20 stainless steel bolts 1-1/2 inches long
1 stainless steel oven rack, or refrigerator rack or grating 24 inches by 24 inches
1 55 gallon plastic drum, or large plastic sink or whatever size plastic container you need to accommodate your large piece of cast iron
2 pcs. PVC pipe just big enough inside diameter to slide over the SS rods
1 square plastic milk crate or bread rack
5 lbs. or more PH+, available at any pool supply store and most Wal-Marts
First step is to cut the stainless steel grate to size that will fit flatly in the bottom of you container. (If you are using a 55 gal plastic drum, cut the top out of it, or cut it to the size you want. I cut off the top 1/3rd of mine).
Next, take you cut grate, lay it flat on the floor. Cut a stainless Steel rod to the length where it will protrude from the top of the plastic barrel when the grate is sitting on the bottom of the container. Now weld the Stainless steel rod to one corner of the grate, where the rod is standing straight up from the grate.
This is your positive + grid.
Take the two pieces of stainless steel flat stock and bend each one into a "U" shape. Drill and tap one leg of the "U" to accept the 1/4 x 20 SS bolts. Weld one of the "U"ís to the end of one SS rod straight down from the end of the rod. Weld the other "U" at a 90 degree angle to the end of another SS rod.
These are your negative - connection rods
Take the plastic milk crate, bread tray or similar plastic grate and cut a piece large enough to sit on top of the positive grid grate in the bottom of the container.
Place your Positive grid in the barrel/container with the 3/8 inch rod standing straight up the inside of the container. Cut a piece of PVC pipe long enough to slide over the rod, but leave about 3 inchs of the rod showing at the top.
Place the plastic grid cut from the milk crate or bread tray, and place on top of the stainless grate, in the bottom of the container.
Using the negative connection that works best for the cast iron piece you are cleaning, attach it to the CI piece in a location where it will stand straight up along the inside of the container on the opposite side from the positive rod., when the CI piece is out into the container sitting on top of the plastic grate.
Now measure the water that you pour into the container as it is important to know how many gallons you have ... Add 1 tablespoon of PH+ for each gallon of water. You can also use washing soda that is sodium carbonate. PH plus, made for swimming pools is 89% pure sodium carbonate and very inexpensive at Wal-Mart.
Make sure you have enough water in the container to cover the complete cast iron item.
Now place the CI piece with the negative rod attached to it into the "soup". Make sure it is resting on your plastic grid and no part of it is touching the Stainless Steel positive grid.
Hook your positive (red) lead from your battery charger to the SS rod protruding form you container that is welded to you bottom grate.
Hook your negative (black) lead from you battery charger to the SS rod connected to you cast iron piece.
The picture below shows how it should be setting inside your barrel.
Turn on your battery charge and let it cook away.
The time a piece needs to be in the soup varies on how much rust and build up is on it and how many amps your battery charger puts out. I use a 35 amp charger.