Anodes on Westerly Centaur

[CaptainBob]

My Centaur has just one anode on the hull which seems to be wasting away nicely.

But I have no anode on the prop shaft, and no mention of an anode in the engine anywhere in my "DIY" volvo penta manual (it's a MD11C).

All seems fine.

Am I missing something? Is my engine about to collapse in on itself?

 

[philip_stevens]

Why don't you ask both of your questions on the WOA sites??


Westerly Owners discussion group

or

Westerly Owners web forum

Lots of Centaur owners with lots of knowledge.

 

[VicS]

[ QUOTE ]
just one anode on the hull which seems to be wasting away nicely

[/ QUOTE ] Rather surprised that you have a hull anode at all. However it should be located near to and within " line of sight " of what it is intended to protect. Presumably that is the stern gear, so it should be in that area but whether it is necessary is debatable. It has probably been put on as a precautionary measure. There may not be room for a shaft anode. Anodes must also be connected electrically to the items they are to protect with good low resistance electrical connection. Ideally that means brushes running on the shaft inboard of the stern gland if it's the stern gear that is being protected. Note that bronze, DZR etc skin fittings should not be connected to the same anodes as other items. Bronze and DZR should not need protecting anyway.

You say it is wasting away nicely. Thats what they do in the normal performance of their duties. Just so long as you don't mean quickly.

You don't say where you are moored but if you are in a marina and have shore power connected all the time, even if not actually in use, that can result in rapid wastage of anodes and other underwater metal bits. The solution to that is to fit a Galvanic Isolator in the earth connection.

You'll find some useful info on anodes on the MGDuff website including a recommendation as to the wire size to couple up anodes and also a recommended minimum distance between a shaft anode and a bronze prop.

The MD11C does not have an anode.

If all seems fine then it probably is.

 

[nigelhudson]

The single anode seems to be standard practice on Westerlys - it's the same on our Storm. I did a continuity check between the anode stud and the propshaft and it was an intermittent circuit. Although we do not have permanent shore-power we keep our boat in a marina where there are likely to be stray currents. So I used to connect the anode stud to the propshaft using an old jump lead which obviously made a continuous circuit and protected the prop.

However on more than one occasion we managed to set off without removing the jump lead from the shaft. As it happened nothing disasterous occurred but we discontinued the use of the jump lead. At our recent haul-out we found pink spots on the prop - it looks like de-zincification of the bronze. So we have now added a shaft anode - you might like to consider doing the same.

 

[CPD]

Bob, I cant answer your question, but VicS, as ever, always has lots if useful suggestions for this sort of stuff. Just to say though, that the setup you describe is exactky the same as that on my 1978 centaur with original md11c fitted. The anode is located between the engine and stuffing box just to starboard. Hope this helps.