Hanging anode

[jez32]

Has anyone used a hanging anode on a P32? My marina eats up anodes and this may help. I know it should be zinc but how do I ensure that the hanging anode is attacked first and where on the boat is best to connect it?

[so36idavid]

In theory tying it anywhere into your DC ground system should work. It should all tie back into the engine block at some point. That's the theory anyway . 

Have you considered a galvanic isolator? They're inexpensive and pretty easy to install. My marina is very hot and I went from a zinc/month to 2 zincs/year after installing one.

David

[jez32]

Sounds interesting. Where do I source one from and how are they installed?

[Spritz]

I am interested too
krs

[so36idavid]

Apr 14, 2015 21:05:48 GMT jez32 said:

Sounds interesting. Where do I source one from and how are they installed?

You should be able to get one though any decent chandlery or there are plenty of online stores that supply them. Just do a google search in whatever part of the world you're in.

The point of a galvanic isolator is to break a DC path through the AC ground. What's probably going on is that some of your neighbors' boats don't have zincs or have poorly installed electrical systems and there is a DC path through your AC wiring. This is allowing current to flow between your zincs and their metal bits. Basically you're paying to protect everyone's hardware. If you're not that big hearted, then you can stop it by breaking the DC path through your AC system. It's basically a big capacitor that interrupts the ground wire so that only AC currents can flow to ground through your AC system. That's a tad dangerous because if it fails then you have no ground so they're built with a bit more than a capacitor in there. They either have a monitoring capacity so that you know when they've failed or they need to fail safe so that if the capacitor fails then it simply reverts back into a closed circuit. I recommend the latter and most modern isolators have that property, at least the ones sold in the US.

If you'd like to see the installation that I have on my 36i I'd be happy to snap a pic. It's pretty simple.

David

[jez32]

Thanks David. I will have a look on the web. A phot would be good when you can.

[Tafika II]

Here is one I looked before I added the isolator...

Attachments:

HangTuff Zinc Anode.pdf (273.91 KB)

[Quiddle]

I use a magnesium hanging anode as my boat is berthed in fresh water but is sailed on the sea. It is bonded by 2.5mm cable which is attached by molegrips to the prop shaft. You can buy a gismo with carbon brushes to go on the prop shaft to enable permenant installation but my system works OK with acceptable resistivity.
I also have a galvanic isolator but am not sure whether this will help with passive electrolysis?

[abgreenbank]

I have a stirling power galvanic isolator, a 60amp affair not the more expensive ABYC type which have to have a more robust fault indication system.
its simple to wire, follow the easy instructions but from the boats AC shore power receptacle it's the first thing connected in line on the earth circuit, so the only earth/ground path from the boat to shore power goes through the galvanic isolator.
rgrds

alistair

ps I have no idea if it works but zincs are still fine after a year

[dublin]

For information

Used a hanging anode for a few seasons. It did not stop the shaft being totally destroyed - marina berth. - but this was not the fault of the anode..
Engineer went to recycle the old shaft and discovered it was not stainless steel - just "pig iron" and recyclers refused to take it.
It was the original fitted by Jeanneau.

[speedbird1]

I've used a galvanic isolator for four years. Works very well. 

My SO45DS has four anodes. Main pear shape, shaft and two on the gori prop. Just changed all four after two years. Metal work all in excellent shape and anodes probably only 40% gone, but then I'm over zealous about anodes. 

Highly recommend the isolator. 

( A fellow berth holder has just pulled his boat. All anodes in perfect condition but shafts and props pitted badly and need replacing. Someone messed up on the wiring. ? ). 

Peter.