Anode on a wire ?

[Andy Bav]

Noted that our anodes are doing their job - but perhaps getting eaten away a tad quickler than I expected. Dock masters have said that our neighbour replaced his after 8 months as his were eaten away quite quickly too.

However a throw away comment was to "hang an anode over the side but make sure its connected to the negative side of the battery", which I am not sure is something that would actaully work, or whether it would just add another anode to be eaten away and not slow down the sacrifice of the existing anodes ?

Anyone ever heard of this - or even done it -and if so what were the results, and how did you connect it ?

 

[sgoodwin71]

quite common in Torquay. connect the wire to the bonding cables thou.

 

[Andy Bav]

quite common in Torquay. connect the wire to the bonding cables thou.

Thanks - can I be thick and ask where the bonding cable are usually located ?@!

 

[beltsandbraces]

i used one once and seemed to work just fine I connected to the engine block for an earth

 

[l'escargot]

Thanks - can I be thick and ask where the bonding cable are usually located ?@!

There will be a cable connected to the stud on the inside of your anode that usually runs to the engine block. As Belstandbraces says you can just connect it to the block. You hang it over the side as near to the parts you are protecting as you can get - usually the stern.

Info here: http://www.anodeoutlet.co.uk/fitting-instructions/57l-hanging-anode-range/

Available here through most chandlers just make sure you get the right one for the water you are in. It will get eaten away as well but the fixed one will get eaten away more slowly.

 

[Andy Bav]

There will be a cable connected to the stud on the inside of your anode that usually runs to the engine block. As Belstandbraces says you can just connect it to the block. You hang it over the side as near to the parts you are protecting as you can get - usually the stern.

Info here: http://www.anodeoutlet.co.uk/fitting-instructions/57l-hanging-anode-range/

Available here through most chandlers just make sure you get the right one for the water you are in. It will get eaten away as well but the fixed one will get eaten away more slowly.

Very helpful.

Many thanks.

 

[l'escargot]

Don't forget to take it in before you set off A bit of cord from the cable to the wheel or throttle can be a helpful reminder

 

[Andy Bav]

Don't forget to take it in before you set off A bit of cord from the cable to the wheel or throttle can be a helpful reminder

Thanks good idea !

 

[maby]

There are commercially available auxiliary anodes that come with the wire attached and a clip to connect to your boat's ground line - very expensive for what they are. Get a medium size "tear drop" anode on a steel bar - the sort of thing you bolt onto the hull of many boats - and solder a decent thickness wire to the bar - a small blowtorch, some plumbers solder and plumbers flux will do it fine - a lot cheaper than the purpose built dangling anodes!

 

[Firefly625]

I have always used a hanging anode to reduce wear on boats anodes, my main anode I replace every 2 years and the hanging anode is one of my old anodes clamped to a cable which attaches to an engine mount....

 

[VicS]

However a throw away comment was to "hang an anode over the side but make sure its connected to the negative side of the battery", which I am not sure is something that would actaully work, or whether it would just add another anode to be eaten away and not slow down the sacrifice of the existing anodes ?

Anyone ever heard of this - or even done it -and if so what were the results, and how did you connect it ?

As said can be bought for this purpose. ( MG Duff and others)
It is important that there is a good electrical connection between the anode and what it is intended to protect.

The battery negative is probably not the best place to connect it to. You should not be using the same wiring for the anode as the DC system and depending on engine and drive there may not be a connection between battery negative and drive etc.
Connecting to the exiting anode wiring or direct to the item to be protected is the way to go.

If you are experiencing rapid anode depletion it could be due to a shore power connection if you leave it plugged in and you do not have a galvanic isolator

 

[Firefly625]

As said can be bought for this purpose. ( MG Duff and others)
It is important that there is a good electrical connection between the anode and what it is intended to protect.

The battery negative is probably not the best place to connect it to. You should not be using the same wiring for the anode as the DC system and depending on engine and drive there may not be a connection between battery negative and drive etc.
Connecting to the exiting anode wiring or direct to the item to be protected is the way to go.

If you are experiencing rapid anode depletion it could be due to a shore power connection if you leave it plugged in and you do not have a galvanic isolator

excuse thread drift.... but I do not have a galvanic isolator and have thought I should get one as I often leave SeaBird plugged in.. can anyone recommend a galvanic isolator?

..would this sort of thing do the trick http://www.ebay.co.uk/itm/70-amp-Galvanic-isolator-with-remote-monitoring-only-8999-2-years-warranty-/171179783128

 

[Andy Bav]

excuse thread drift.... but I do not have a galvanic isolator and have thought I should get one as I often leave SeaBird plugged in.. can anyone recommend a galvanic isolator?

..would this sort of thing do the trick http://www.ebay.co.uk/itm/70-amp-Galvanic-isolator-with-remote-monitoring-only-8999-2-years-warranty-/171179783128

Cant access e.bay at work, but was looking at one of these for £99.99 ...

http://www.safeshoremarine.com/Galvanic isolators in a nutshell.htm

Not sure if its any good though ..

 

[l'escargot]

excuse thread drift.... but I do not have a galvanic isolator and have thought I should get one as I often leave SeaBird plugged in.. can anyone recommend a galvanic isolator?

..would this sort of thing do the trick http://www.ebay.co.uk/itm/70-amp-Galvanic-isolator-with-remote-monitoring-only-8999-2-years-warranty-/171179783128

I've got one of those, didn't bother with the remote monitor though. Seem well made and quick delivery.

 

[maby]

Cant access e.bay at work, but was looking at one of these for £99.99 ...

http://www.safeshoremarine.com/Galvanic isolators in a nutshell.htm

Not sure if its any good though ..

They are very simple devices and there is not much to choose between them. They are sold with a current rating, but it is a fairly academic figure. Inside you have a couple of high power rectifier diodes and the quoted rating is the steady state maximum current that they can carry - a few tens of amps. If you have a wiring fault on the boat, the isolator will have to carry a current measured in thousands of amps till the circuit breakers trip out - a fraction of a second. None of the diodes used are actually rated for this and all will fail if the breakers don't trip quickly. The theory is that the higher rated diodes stand a better chance of surviving, but there isn't much proof of this really.

 

[superheat6k]

I have been using a dangling anode on the pontoon side this year as my anodes fizz to fast. I fitted a GI, but then found the reverse power LED indicator was providing a neat bypass around the GI, so I removed this, then found a small DC leakage current through the bilge pump float switch in the engine bay, and I think this was the major culprit.

I traced this by measuring the voltage from the battery +VE to the disconnected +VE cable lug with everything switched off. This should have been zero volts but was approx 4 volts DC. This is now an annual check for me, plus I have binned the flappy style float switch in favour of a solid state switch.

If you make one from old pear or bar anodes it is important to use stainless or galvanised steel wire onto the anode for the section that sits in the water, connecting onto heavy copper (e.g. 4mm2) above the water level onto the bonding circuit. If you use copper below the water it will create unnecessary galvanic problems, especially if you have any aluminium parts nearby, e.g. outdrives, thrusters etc.

 

[coreng]

Anode or not anode?

Anodes are not a guess and intended to deliver only needed quantity of protective current. No more (over-protection), no less (under-protection). Quantity of current, depending on nature of protected equipments, are well known now and depends upon several factors... If your anodes are eaten in 8 months, it is probably due to environmental conditions (electrolysis would deplete them much faster). Put bigger ones at next haul out...

 

[maby]

I have been using a dangling anode on the pontoon side this year as my anodes fizz to fast. I fitted a GI, but then found the reverse power LED indicator was providing a neat bypass around the GI, so I removed this......

Interesting! How was the reverse polarity LED connected to bypass the GI?

 

[superheat6k]

Interesting! How was the reverse polarity LED connected to bypass the GI?

The boat originally had a neon reverse power indicator sitting between neutral and earth. if when plugged in to shorepower live is on neutral the neon would light up.

This was knackered so I replaced it with a modern 240v LED. I then noticed one evening it was very faintly glowing, barely discernible but definitely glowing.

The key difference between a neon and an LED is the resistance - a neon is close to infinity, an LED isn't, and this still high resistance was still enough to allow the galvanic current flow at a few milliamps, so the earth at very low level of current / conductivity was effectively connected onto the neutral line straight past the GI on the neutral line which is grounded at the shorepower source transformer.

 

[Firefly625]

Cant access e.bay at work, but was looking at one of these for £99.99 ...

http://www.safeshoremarine.com/Galvanic isolators in a nutshell.htm

Not sure if its any good though ..

that is the same as the one on ebay, but interestingly cheaper on eBay. Think I might get the one without remote monitoring now due to comments, TBH I don't think I really need remote monitoring as I can check the unit easy enough. Many thanks and excuse slight thread drift.