Anode Hanger Question

[jon and michie]

Hi - I am in the process of making an anode hanger using a stainless steel threaded stud bar to hold the anodes with stainless steel mig wire approx 0.8mm thick to connect to the earth on the boat - as well as a strong wire to take the weight.
My question is could I connect a normal copper insulated electric wire from my shore power lead socket's earth with a crimp to the connect to the stainless wire ?
This would save me from opening up a panel in a really awkard to get area.
all opinions welcome
Jon

 

[Stemar]

You're getting a few connections of different metals there. Add sea water and each connection becomes a battery. I don't know enough to say how much of a problem it would be, but I'd be a bit leery of doing it. Maybe use galvanised steel for the wet bits, at least?

 

[jon and michie]

Thanks steve - I am on the thinking that the stainless mig wire with a connecting crimp to the earth wire of the shore power lead which in turn is copper anyway wouldnt make much difference. as opposed to having copper insulated wire actually connected to the hanger under water.
Or would it be better to have copper wire from the hanger with a crimp going to the shore power lead's earth?

jon

 

[Quandary]

What is this anode protecting?

 

[duncan99210]

Quandary has asked the right question. An anode has to be connected to the item it’s designed to protect, so connecting it to the shore power earth won’t protect anything. If you think there‘s an item in the water that might be subject to galvanic corrosion, you need to connect your hanging anode to that item and hang the anode in such a position that it is near to the item.
Without knowing what you want to protect, we can’t offer advice as to how to protect it.

 

[VicS]

Hi - I am in the process of making an anode hanger using a stainless steel threaded stud bar to hold the anodes with stainless steel mig wire approx 0.8mm thick to connect to the earth on the boat - as well as a strong wire to take the weight.
My question is could I connect a normal copper insulated electric wire from my shore power lead socket's earth with a crimp to the connect to the stainless wire ?
This would save me from opening up a panel in a really awkard to get area.
all opinions welcome
Jon

Look at the way MGDuff make their hanging anodes .

No don't connect it to your shore power socket

It must have a good electrical connection to the item it is to protect.

Often used to give additional/ backup protection for a sail drive... If so it must be connected to the saildrive itself because there are usually isolated from the engine and the electrical system

 

[jon and michie]

Right - Many Thanks for your replies so far.
I am after giving further protection to my out drive leg - I do have a galvanic isolator installed (I think this is I was thinking to just connect to the earth on the shore side socket).
so my next question is if there is continuity from the drive leg to say a nut and bolt on the engine for example could I then use that as a connection point as it is linked to the drive leg?
Jon

 

[Quandary]

No, If its VP they will be isolated from each other, you need to connect it to the leg, when I did it I removed a bolt, cleaned away the paint to give the terminal good contact and put it back. Insulated copper wire to the locker where the anode was stored and then bare stainless for the drop. Less joins the better. At the time a Plastimo anode was half the price of an MG Duff one. If your outdrive comes up when not in use you may not need it?

 

[vyv_cox]

The MGDuff hanging anode kits use PVC coated galvanised (or as they say galvernised) wire. Stainless steel is not a great conductor of electricity. See TIBTECH innovations: Metal properties comparison: electric conductivity, thermal conductivity, density, melting temperature. Insulated copper would be better still.

 

[jon and michie]

Right as like most folk in lockdown I have a bit of time on my hands and resurecting this thread.
so if I have got this right here is my thinking.

Old anodes bolted on a stainless steel threaded stud bar - the stud bar weight supported by a stainless steel wire.
Now the connection part - Can I use standard insulated copper wire (standard electric wire) to connect the anodes to the drive ?
As Quandry has stated (post#8) the connection needs to be direct on my drive leg however I really dont want to touch the drive leg as less than 2 years old and still has warranty but if I did find that on the engine there was continuity would this work ?

Jon

 

[Quandary]

Why do you need to do this? if the immersion is in salt water the zinc leg anode already in place will protect the leg.
I had to do it because most of the time our boat is kept in fresh water but goes to sea for extended cruises. Zinc anodes passivate in fresh water making them ineffective in the sea, and at the time the only other choice was magnesium which degraded too fast in salt water. So I needed a zinc anode that I could bring on deck to abrade the surface regularly to remove the passivation.
Today you can buy aluminium leg anodes (Solent Anodes) which, while they do erode faster than zinc will normally last at least 2-3 seasons.
If you really need to do this it is not difficult to find a bolt or stud on the gearbox that can be carefully removed and replaced, if necessary, the torque settings can be found in the workshop manual as well as advice on what is simply a securing bolt as against one that has a mechanical function. Note that you are only protecting the leg, the prop. (particularly folders) may also need a separate anode as it is normally isolated from the leg by a rubber block within the hub. In my experience with three saildrives, all VP, the propeller is more vulnerable than the leg.

 

[Quandary]

To directly answer your last question, A heavy copper wire is fine, as is insulation, you could even just fix your old anodes directly too it which would be better than the stainless with extra connections I might not last quite as long but put a loop in it to give you extra length allows you to discard the corroded end. Old anodes will be hard to clean if they become passivated. Bridging the isolation between engine and drive is not at all a good thing to contemplate, You are protecting your saildrive leg so the connection should be to the leg or the gearbox casing.
But it still comes down to purpose; you only need to do it if the leg anodes are not functional through passivation or some other defect, your discarded anodes will be hard to clean if that is your purpose (coarse sandpaper is more effective than a wire brush) the smooth bullet shape of a proprietary hanging anode is much easier cleaned, but if you can clean half the surface that is probably enough.
Edit, probably already mentioned - anodes to hang as close as possible to what they are protecting.

 

[superheat6k]

When I make hanging anodes I use a short piece of stainless rigging wire for the immersed section, then connect this to a piece of 6 or 8mm rope, and thread along this a hefty (~4 - 6mm2) copper cable, linking to the stainless above the water. Then attach this to the bonding circuit.

If you internally connect the guardrails to the bonding circuit these make a very convenient point to attach a large croc clip. Or boat side of the GI.