salty water

[pooie4]

I was chatting with a customer the other day and he said something that started me thinking . while we are all under attack from corrosion(not fibre glass, or grp)I wondered if mooring up in an area where there is a high salt content in the soil might have effect on how quickly the hull rusts as it must leech out of the ground, not so much on the canal but in marinas...?? any thoughts . would it do more harm than stray electrical current. or is it likely to be nothing to worry about..

Edited June 18, 2014 by pooie4

[PaulG]

I was chatting with a customer the other day and he said something that started me thinking . while we are all under attack from corrosion(not fibre glass, or grp)I wondered if mooring up in an area where there is a high salt content in the soil might have effect on how quickly the hull rusts as it must leech out of the ground, not so much on the canal but in marinas...?? any thoughts . would it do more harm than stray electrical current. or is it likely to be nothing to worry about..

Depends how salty the water is.

They usually recommend magnesium anodes for fresh water and either aluminium or zinc for salt water.

[Paul C]

I was chatting with a customer the other day and he said something that started me thinking . while we are all under attack from corrosion(not fibre glass, or grp)I wondered if mooring up in an area where there is a high salt content in the soil might have effect on how quickly the hull rusts as it must leech out of the ground, not so much on the canal but in marinas...?? any thoughts . would it do more harm than stray electrical current. or is it likely to be nothing to worry about..

 

I'm not sure it "leeches out of the ground", at least significantly, since canals are lined to prevent water draining out of them into the ground. Yes there's a few places where the canal isn't lined that well, though; and there's runoff water which enters the canal eg when the surrounding level of the land is higher AND its been raining AND there's no other drainage, but its the exception rather than the rule.

[frangar]

The water in Salthouse Dock in Liverpool is pretty brackish....it's great for cleaning the weed off your hull and you can watch your anodes fizz a bit...if you moored there all the time you might want zinc anodes instead of magnesium.

 

Cheers

 

Gareth

[Max Sinclair]

The Droitwich Barge Canal can be up to 30% Saline.

When the BBC was filming Blue Peter with John Noakes and Shep at Mildenham Mill Lock a camera man put his aluminium carrying case on the cill for a couple of hours and was shocked at the corrosion etching.

http://s1196.photobucket.com/user/outriggerian/slideshow/john%20noakes

 

Near the Salwarpe weir in Vines Park a pipe continually runs strong brine and the locals have used it for years as weedkiller.

The Oldbury phosphorous used to strip hulls and give them a phosphate coating, ideal for paint preparation.

Edited June 19, 2014 by Max Sinclair

[Naughty Cal]

I was chatting with a customer the other day and he said something that started me thinking . while we are all under attack from corrosion(not fibre glass, or grp)I wondered if mooring up in an area where there is a high salt content in the soil might have effect on how quickly the hull rusts as it must leech out of the ground, not so much on the canal but in marinas...?? any thoughts . would it do more harm than stray electrical current. or is it likely to be nothing to worry about..

 

GRP and wooden boats still have to be corrosion protected. Not the hull but the propulsion shafts/props/drives and skin fittings still need to be protected with the relevant anodes.

 

We use aluminium anodes as we are continually switching between fresh, brackish and salt water.