Aluminum anodes in cooling water

[kevlar49]

Does anyone have experience with aluminum anodes in cooling water heat exchanger channels to protect pass partition plates? Our experience with zinc anodes suggests that they are consumed too quickly. Some limited experience (second hand) suggested that aluminum anodes broke off in chunks and plugged tubes. At the time, I thought it might have to do with improper heat treatment leading to intergranular corrosion.

any comments?

 

[TheBlacksmith]

What is your cooling medium; salt, fresh, brackish, polluted? What is the potential difference between the anode and the heat exchanger. Making the anodes last longer without understanding why they are being consumed so quickly may result in corrosion of the heat exchanger. We used to use zinc in saltwater and aluminum in freshwater on outdrives. Aluminum in saltwater corroded even faster.

 

[TheBlacksmith]

I just remembered, it was magnesium anodes we used in freshwater that would be consumed very rapidly in salt. Still, you need to determine that your heat exchanger is protected, then worry about anode consumption. One interprising engineer from a Navy (not US) solved the frequent anode replacement problem by machining duplicate pencil anodes out of 316 stainless. They outlasted the diesel engine heat exchanger!