Shaft Anodes - material

[vasko]

I have two shaft anodes at the moment - from Zinc - but as I moved to a new marina and the water is a little bit of mix between salt and fresh water in the new marina I'm planing to change from two Zinc to one Zinc and one Aluminium...


Does someone knows if having two different material anodes on the same shaft may be a issue ?

[MartyB]

Keep them the same, as the two have different removal rates. You will probably find the zinc may go away before the aluminum or the other way around. I would go with two aluminum if it were me. I am actually using aluminum in salt water currently. As zinc is sorta kinda being outlawed to not recommended due to the how bad it is in the environment. I use three shaft anodes where I am. But the marina is known to be a hot one. I get about 4-5 months from three.

Marty

[sitara]

Have a look at www.marineprotectionsystems.com.au/. There is some good information here about how anodes work and what material they should be made of. Also info about galvanic isolators.