Heat Exchanger Anode Deposits

[pdbms]

My diesel is a Ford 120hp. It has an anode in the water jacket of the heat exchangers on the transmission and the engine. When I purchased the boat, both anodes had been almost completely consumed. I replaced them with new ones. Twelve months later, when I checked these anodes, rather than being consumed, they are having a greenish buildup deposited on them. Can anyone tell me what is going on here?

[David M]

Your anodes may not be grounding to the heat exchanger. Did you use Teflon tape?

[pdbms]

One of the anodes is a pressed fit into a brass threaded cap. The other threads into the brass cap. Both brass caps then thread into the heat exchanger.

[awpptdt]

These anodes are small in comparison to all others, plus they are in a moving electrolite solution and should be checked every six months. They need to be bonded to the heat exchanger, ie, no teflon tape that will insulate them from the heat exchanger. The green is corrosion due to copper being leached out of the heat exchanger, if allowed to continue the heat exchanger will fail and sea water will enter the other side. If this happens replace them with copernickel ones as they resist corrosion. J.T.Duncan