Anode metal transfer

[JardiTancat]

I sail on Fresh water Lake Ontario and therefore use magnesium anodes, one on the shaft and one fitted to my maxi prop. When hauling for winter lay-up the last two years both the shaft and the prop are completely coated with a magnesium film. I understand the principle of sacrificial metals but I don't understand why this coating is happening. Is there anything here to worry about?



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[Andina Marie]

That is how a plating process works, you put the metal you want to plate, and a piece of the metal you want to plate on it in a conductive liquid, then pass a current through. Since you are not in a sealed container the water flow must be about zero in the vicinity.

It seems to me like it would be an advantage - you now have magnesium plated underwater metal parts so if any electrolysis is to occur it will have to take the plating off first. It should also extend anode life since the metals will now all be at the same potential and current will drop to zero.

[sailorchic34]

That sounds normal too me. Electrolysis does actually transfer molecules from the anode to the cathode.

[Stumble]

Working as intended. A little odd in that normally you can't see where the metal goes from a boat anode it tends to disperse to quickly.

[JardiTancat]

Thanks for all this. It's nice to actually see the results of anode protection however I too thought it a bit odd to see it so graphically. Perhaps I'm just lucky and will have accidentally found the "permanent anode"! Cheers all.


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