mooring chain corrosion

[tyce]

hi, this is just a thought that has been niggling in the back of my head, my mooring root is two very big electrical motors that has the shaft removed and the chain ran thro the middle in contact with the copper.

because of galvanic corrosion will the copper eat the chain in extra quick time or can i stop worrying about my boat drifting into the sunset with a .5mm thick chain connected to it.

 

[Ships_Cat]

I think that I would worry and at least want to check what is happening down there, although one assumes that the insulating coating on the copper wire will provide some protection for a while. This especially as the surface area of the steel chain is likely to be much less than that of all the copper it is in contact with (similar to using a small steel fasteners through copper plate, they corrode very fast).

John

 

[ongolo]

If you could get the motor up for a short while, you could consider adding a lot of secondhand zinc anodes, they get taken off ships and are often very big and servicable still. Find them in a scrapyard near a drydock

I have anades on my 60kg mooring anchor


regards ongolo

 

[Jcorstorphine]

I think you have a disaster waiting to happen. I once seized a shackle on my mooring with a short length of “tinned” copper wire as I could not find any galvanised wire at the time. Mooring was only down for about three months and when I lifted the mooring, the shackle pin had dropped to about ¾ of its diameter and the hole in the shackle had increased as well so that all that was holding the pin was the copper wire.

The shellac insulation may keep things at bay for a short time however the action of sand and seawater will abrade away the insulation and you will be left with a classic example of a “Primary Cell.” Don’t think your insurance company will look to kindly if they find out the reason for your boat going on the rocks.

 

[alahol2]

I'd be very worried, copper wire has a disastrous effect on shackles under water. I hate to think what that amount of copper is doing to the mooring chain. I'd get them out and replace them with concrete or proper mooring anchors. Don't leave them lying around in the mooring area.

 

[William_H]

The best advice so far is to have a look. I wouldn't be surprised if there is no unusual corrosion as the chain may not be contacting the copper, however you are right to be concerned. The easy fix is to find another weight and chain it to the mooring chain to give a standby mooring if the electric motor chain fails. You need to check any mooring chain often. I have a 10 mm chain (diameter of metal in the links) and after 2 years it is worn halfway through.
How deep is it? get yourself a good wet suit and weight belt, if is only 3 metres on low tide you would be surprised what you can do holding your breath and of course it means you can inspect the boat clean hull etc. Or have I no idea how cold the water is in UK. regards will PS 39degrees max here on Friday just off for a quick swim around the boat no wetsuit needed.)

 

[TheoSr]

Having no experience with moorings at all, living in the Netherlands, I was wondering why a chain has to be used. Isn't there some suitable plastic rope to replace the chain. Properly protected inside these motors with some heavy duty plastic hose. No rust, no shackles, no corrosion.
Just a thought,
Theo.

 

[alahol2]

You are perfectly correct Theo. I have a fore and aft mooring and I use 6cm diameter 'ship mooring' rope from the very heavy (4cm) ground chain and anchors to the deck. So far it has lasted about 10 years with no visible signs of deterioration (touch wood). Previous to this I was changing shackles, riser, swivel etc every few years. Any mooring really needs checking every year and even than it's difficult to be certain. I just hope I'm not tempting fate by writing this. /forums/images/graemlins/confused.gif