Ok, those with some electrical or metallurgical knowledge may be able to answer this for me. As you know, when you screw a piece of cast iron to a piece of brass in the presence of water, you form a very small battery. The dissimilar metals form a current due to electron flow from the iron to the brass. This galvanic corrosion will oxidize the cast iron.
The reason I ask, is I had cast iron elbows screwed into my water pump & thermostat housing. A brass hose barb was screwed into each elbow to bring water to & from my heated manifold. Well, when I took my old engine apart, I found corrosion in the iron elbows, and a little corrosion in the thermostat housing and water pump. Those fittings were installed less than a year previous.
How serious is galvanic corrosion in the presence of ethelyne glycol antifreeze? Should I try to find nipples made out of iron, or what? I'm afraid of causing some sort of cooling system damage due to this. Is it just caused by the grey iron elbows? Would screwing brass fittings directly into the water pump and thermostat housing cause the same issues?
thoughts?
chip
