Hey Rick....I believe we have always referred to the scrap iron or stainless steel as the donor piece as that is the piece that usually gets destroyed, in the case of the scrap iron or steel anyway. The stainless steel fairs a little better if it is a good quality SS. When you talk about Anode and Cathode, a simple way to remember is: Anode = current flows in, Cathode = current flows out. So, for the most part, you could say your scrap iron, or "donor" piece would be your anode, and your piece to be cleaned would be your cathode. But to confuse the matter a little for you....if you reverse your charger leads, then the anode becomes the cathode, and the cathode becomes the anode. You don't want to do that though unless you want to destroy the cast iron that you are trying to clean. Best to just remember the RED or positive lead goes to the scrap or donor piece, and the BLACK or negative lead goes to the piece being cleaned. Hope that is all clear as mud for you. BTW....it sounds like you will have a substantial "donor" piece when you are finished welding it all together. Two more comments or suggestions....you might be better off hanging your cast iron inbetween the iron or steel box that you are making instead of setting it on a plastic crate. You may find that you have a faint pattern of the crate on your clean iron. Also, drill some holes in your welded iron plates to allow the soup to flow around your cast iron a little better (but you probably already knew that.... ;D) Also, as you noted, the cleaning process is more or less a "line of sight" operation, so, if your "donor" piece is lower than the top of your piece being cleaned, the cleaning process will not be as efficient, and you will most likely have to turn the cast iron over so that the other half gets cleaned better. I think it has been talked about before, but your cast iron should be completly submerged in the solution when being cleaned. Good luck....show us some pictures of your set up and the results when you try it out.
Scott
