MD2040 and Pink Bits

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4 Feb 2003
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www.BrendanChandlerYachtDelivery.co.uk
<span style="color:blue"> Is it not unusual not to have 'zincs' on a modern engine cooling water system OR have I missed something?

I consider Electrolysis to be a black art. The gear box of an MD2040 is electrically insulated from the engine. My shaft is connected with brushes to the zincs/earthing system.
Is this correct?
I ask because I see pink patches on my prop. I am sure that some of these are due to shellfish which seem to leech metal from the prop.

As always, I bow before the fount of knowledge available here.

Thanks

Brendan </span>
 

johnalison

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Do you not have an anode on the shaft as well? I'm not sure I'd be happy without. Electrons are funny animals and I don't think they like swimming further than necessary.
 

boatmike

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With fresh water cooling the need for the engine itself to have a zinc anode is removed but it is a good thing to have one in the salt water side. Often these are found in the housing of the tube stack as a screw in bolt with a tiny zinc on the end. Because they are IMHO totally inadequate they often dissapear completely and the bolt is mistaken for a drain plug which it often doubles as. Some modern engines don't have one at all on the basis that people don't change them anyway I suppose. (?)
As far as the shaft is concerned, brushes connected to the anodes is fine but the anodes themselves need to be near the prop to be effective. If there is room, a shaft mounted anode is better and less complicated.
 
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Thanks for help,
I cannot find any bolt on tube stack.

No room for anode on shaft, well perhaps a tiny one. If I can find a small one, I will try to fit that.

Given that even I as a liveaboard ocean cruiser spend 80%+ of my time anchored, would there be any joy in suspending an anode near the prop from a wire joined to the 'Electrolysis Circuit'?
 

john_morris_uk

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[ QUOTE ]
Thanks for help,
I cannot find any bolt on tube stack.

No room for anode on shaft, well perhaps a tiny one. If I can find a small one, I will try to fit that.

Given that even I as a liveaboard ocean cruiser spend 80%+ of my time anchored, would there be any joy in suspending an anode near the prop from a wire joined to the 'Electrolysis Circuit'?

[/ QUOTE ]There is no anode on the MD2040 - so stop your search! We have the same engine and fortunately there is room on our shaft for an anode, and as we have a max-prop, there is an anode on the prop as well. If there is no room to get a shaft anode on (there are some 'collar' type that are fairly small and worth considering) make sure that your anode connected via the brushes is as close the the prop as possible. Suspending an anode over the side near the prop, with a good electircal connection would be a good idea in the interim.
 
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