Non-Vanishing Anodes

[Budgie]

I have had a 40 footer with Volvlo saildrive for the last few years. Each winter I have found that the saildrive anode has vanished almost to the point of invisibility. The hull anode has also been well worn. The saildrive leg was antifouled, but the prop blades and boss were always polished and left in metal finish.

Last winter (2002/3), for the first time, I applied MPX antifouling additionally to the folding prop blades and boss. On lifting the boat last week I found that the prop was free of fouling and that the saildrive and hull anodes were virtually intact.

Is this just coincidence, or does antifouling the prop blades reduce the electrical charge on the propeller?

P.S. The boat is normally plugged in to shore power when in the marina. The boat usage this year has been similar to past years.


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[extravert]

When I fitted a brand new shiny bronze propellor, my anode disappeared quickly. The subsequent year when the prop had tarnished to the normal dull brown colour, the anode was much less worn. I don't know if the reason for my experience is the same as yours, but sounds possible.

<hr width=100% size=1>One day, I hope to own a real boat (and a reliable lifejacket).

 

[snowleopard]

the electrical potential between zinc and bronze is very high. painting effectively insulates the prop so takes it out of the equation.

this can only be good news because the zinc isn't there to protect the prop but the steel and aluminium parts.

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[tome]

<the zinc isn't there to protect the prop but the steel and aluminium parts>

Where do you get this from, Snowleopard? Any metal which is nobler than zinc (ie all) will be protected, shoooorly?

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