Sneakers O'Tool wrote:
I did the brutus 10 build with mild steel (regular). And to answer your question, since stainless doesnt rust, the rust on the mild steel may get on your SS kettles, but wont make them rust due to their lower iron content and higher carbon content. Just a thought, have you thought about coating your steel to prevent it from rusting? Like engine block paint, powder coating, or any other high temp sealer...
First off I would like to say stainless steel will rust if introduced to mild steel. That is why I seperate, and have two sets of tig equipment for mild steel and stainless steel. Also the reason stainless steel doesnt rust is due to the high chromium and nickel content, as well as the low carbon content. If you that concerned about it then just store your kegs somewhere else than on top of your mild steel sculpture, or just keep them on the sculpture and hit it with a little BKF every once in a while. IMHO I think your being a little paranoid!
The susceptibility of different base metals to corrosion while in contact, depends upon the difference between the contact potentials, or the electromotive voltages of the metals involved. The greater the potential difference is, the greater is the tendency for corrosion. The metal with the higher potential forms the anode and is corroded. In other words, the larger the separation distance in the electromotive chart between the two metals in contact, the higher the contact potential and chances for corrosion. On our charts, Stainless is at the end of the Cathodic (-) chart while Steel is at the other end, Anodic (+).
As a general guideline, if the metals are half the length of the chart or more apart, the combination should be avoided. Also, it is not a good idea to combine an anodic metal part with thin
cross section, such as thin wall tubing, with a cathodic or less anodic metal part of a heavy cross section, such as a fitting. With that said, the pot to structure interface, does not have the contact surface area that fittings, tubing, etc. have. Go at it.
Sorry - Long winded - I love fittings..........