Mixing Anodes

[whisper]

Anyone know whether or not it's OK to mix zinc and aluminium anodes together, or near to each other?
Thinking of fitting zinc ring anode on the outdrive leg and two aluminium bar anodes on the transom "shield".
Thanks in anticipation.
John

 

[VicS]

Should be no problem. The aluminium anodes are an alloy containing a small amount of indium and have a potential very close to that of zinc. They vary a little and depending upon the exact alloy the aluminium ones might just waste in preference to the zinc if they are close but probably not by very much. The aluminium ones are cheaper anyway so that may be an advantage!

Cant get an aluminium anode for the out-drive leg ?

 

[whisper]

Thanks for the reply.
Haven't found any aluminium ring anodes for the leg, only tapered bar ones for the transom. They are actually more expensive than the zinc versions but will last longer, allegedly.
You may know different /forums/images/graemlins/smile.gif

 

[VicS]

It is claimed that aluminium anodes last about 25% longer but I cannot confirm it. I thought they were supposed to be cheaper!

 

[whisper]

Some are and some aren't - varies with the type required and/or supplier.
Nothing's ever simple , is it?