anodes

[EASLOOP]

What devices are available to connect the rotating s/s prop shaft to the boat's hull anode (wooden hull). I can do the engine block of course but that is not spinning!?

Any ideas would be most welcome

rgds
John

<hr width=100% size=1>

 

[ccscott49]

I have seen a little rotating sleeve, with a copper "brush" on it, which makes a connection between shaft and anode, but not sure who makes it, halyard?


<hr width=100% size=1>

 

[pvb]

Electro Eliminator...

The most common device for this is called the Electro Eliminator, and it's available from places like <A target="_blank" HREF=http://www.asap-supplies.com>ASAP Supplies</A>. I've never quite understood why people fit these, because unless there's an insulated flexible drive between gearbox and shaft, the propshaft is already electrically connected to the engine. I think some people use the Electro Eliminator to overcome electrical interference problems. If cathodic protection is the aim, it would seem that a shaft anode or a prop nut anode would do a better job at much less cost.

<hr width=100% size=1>

 

[Bodach na mara]

The reason an "Electro-eliminator" is used is the resistance across the gears. I checked for continuity between anode and prop and found it fairly low on my boat, but on another boat it was highter and there was no flexible coupling. I cannot use a shaft anode myself as there is no room between prop and stern bearing.

<hr width=100% size=1>Ken Johnson

 

[EASLOOP]

Thanks chaps. I feel certain that there will be a reasonable contact between engine block and shaft but I like the sound of the copper brush. I will look out for same.

best wishes
John

<hr width=100% size=1>

 

[maxi]

Re: Electro Eliminator...

As ever, pvb makes a good point, however, a word of caution regarding shaft anodes and prop-nut-anodes. Anodes are effective in relation to their mass, therefore if there is a lot of zinc loss on a small anode it becomes rapidly less and less effective.

Shaft and prop-nut anodes are usually very much on the small side, especially the latter & whilst they undoubtedly work they also need to be very regularly renewed.
It may be more economic and effective to fit a decent sized anode, properly bonded, and which will last several seasons unattended.

As for your spinning shaft, try adapting one of the brushes out of a dead Black & Decker or even a piece of spring metal bearing onto the shaft will give you your connection, simply and cheaply.

<hr width=100% size=1>