Bonding skin fittings to hull anode

[killick]

A while back there was some discussion about bonding skin fittings to the hull anode and,if I recall correctly,the majority opinion was that it was not necessary. This was subject to there being a shaft anode to protect the propeller.
If this is correct what is the function of the hull anode and do I need one at all?

 

[vyv_cox]

Current thinking, at least on this side of the Atlantic, is that underwater fittings are protected from corrosion by their metallurgy. No need whatsoever to add an anode. When I bought my boat 20 years ago one of the first jobs I did was to remove all the trailing wires and a hull anode. Never had a problem since. Does help if you know that said fittings are made from appropriate materials, of course.

The USA insistence, via ABYC, on hull anodes seems to be more to do with lightning protection than with corrosion.

 

[Ardenfour]

Replacement hull anode is still on my 'to do' list since launch last October (i did fit a new shaft anode) wires for the hull anode lead to the engine block. none of the thro hulls are wired. the old anode was seriously depleted, so it must have been doing something...

 

[GrahamM376]

Replacement hull anode is still on my 'to do' list since launch last October (i did fit a new shaft anode) wires for the hull anode lead to the engine block. none of the thro hulls are wired. the old anode was seriously depleted, so it must have been doing something...

My prop and shaft have anodes and there's also a bonding wire across the flexible coupling. The main hull anode is connected to the engine block, P bracket & rudder bottom bearing, it needs replacing every 2 years so is obviously working. Only have one metal through hull below waterline which isn't bonded, the rest are composite TruDesign.