i was looking to use it as a sacrificial anode. i've got an electric HLT and rust formed on the element base just from sitting overnight in water. i can only guess the same thing is happening to the RIMS element, i just haven't taken it apart yet. putting an anode in an HLT is easy, and i was looking for something comparable to do for the RIMS heater.
from wikipedia (the "galvanic corrosion" entry):
"For example, consider a system is composed of 316 SS (a 300 series stainless steel; it is a very noble alloy meaning it is quite resistant to corrosion and has a high potential) and a mild steel (a very active metal with lower potential). The mild steel will corrode in the presence of an electrolyte such as salt water. If a sacrificial anode is used (such as a zinc alloy, aluminium alloy, or magnesium), these anodes will corrode, protecting the other metals."
FYI, people who use aluminum kettles or weldless fittings with aluminum locknuts would never see the base of their electric elements rust.
p.d.