Another anode question

[CalicoJack]

Our Neptunian has not lost much of its anode this year; it hasn't lost much in the two years that we have owned her. It has a wire running from the anode to the negative terminal of the domestic battery. Is this sufficient, or should there be more?

 

[MoodySabre]

There should connectivity to the things that the anode is trying to protect. My hull has wires to the engine, P bracket and sea-cocks but not to the battery - I suppose that earths it to the engine. Put a multimeter between the anode and Prop etc and check that there is continuity. I also have a shaft anode. Anodes are cheaper than props!

 

[VicS]

[ QUOTE ]
It has a wire running from the anode to the negative terminal of the domestic battery.

[/ QUOTE ] Your hull anode(s) should be connected directly with a good low resistance connection to the items it is to protect. It/they should also be reasonably close to those items. The MGDuff website recommends a gauge of wire to use.
Sometimes the anodes are connected to the engine /gearbox in an attempt to protect the stern gear. If stern gear protection is needed then it is probably more effective to use a shaft anode where that is possible or to connect the hull anode to the shaft via brushes inboard of the stern gear than to rely on there being a good low resistance electrical path from the engine via the well lubricated components of the gearbox to the stern gear.
Again the MG Duff website shows what is needed.