Rusty Chain?

ducked

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That link reminded me of flame spraying of zinc or zinc/aluminium mix. Is that still done?

I'd think chain might be too awkward and fiddly a shape, and thus too labour intensive to be commercially viable, (though it ought to be good on keels) and a DIYer probably couldn't get the kit.

You can get aluminium wire for MIG welders though...
 
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Neeves

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That link reminded me of flame spraying of zinc or zinc/aluminium mix. Is that still done?

I'd think chain might be too awkward and fiddly a shape, and thus too labour intensive to be commercially viable, (though it ought to be good on keels) and a DIYer probably couldn't get the kit.

You can get aluminium wire for MIG welders though...
There are a number of techniques to apply metal coatings onto a metal or non metallic substrates, some work (vacuum deposition of aluminium onto film) or plasma spraying - there are lots of ideas and research but if there was a mechanism to rust proof steel - we would know.

Sharardizing, aka Armorgalv, aka Green Cote, aka Thermal Diffusion Galvanising is the only industrial process I know that has been adopted (in a niche market) ..... and used on chain.

Jonathan
 

NormanS

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This is not at all relevant, but all this talk of chucking stuff into bonfires reminds me....
Many many years ago, I was just a boy, but I had acquired a small old ship's lifeboat, which I rigged with a gaff main, and two jibs. A friend made me all sorts of fittings for the boat, but they were of course mild steel. At that time, an accepted practice was to heat the steel in a fire, to a "good black heat", and then plunge it into Gas Works tar, which was readily available. The heat burned the tar onto the metal, and provided it was taken out of the tar before all the heat was lost, it dried with a shiny finish. Obviously , this was never as good as galvanising, but the protection lasted well. It was also great fun.
I won't go into any detail about the time, when coming home in the bus with a five gallon metal container of tar, it became apparent that the container had developed a leak. 🙂
 

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There are a number of techniques to apply metal coatings onto a metal or non metallic substrates, some work (vacuum deposition of aluminium onto film) or plasma spraying - there are lots of ideas and research but if there was a mechanism to rust proof steel - we would know.

Sharardizing, aka Armorgalv, aka Green Cote, aka Thermal Diffusion Galvanising is the only industrial process I know that has been adopted (in a niche market) ..... and used on chain.

Jonathan
I believe flame spraying is a long established technique for rust prevention on steel. I just doubt it would be practical on chain, due to the shape.

https://thermalsprayzinc.zinc.org/about-thermal-spray/

I suppose there could be health and safety issues with it that could cause it to fall out of favour, but I assume the temperature of application isnt high enough to generate the same hazards as are generated by welding galvanised steel
 

rogerthebodger

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I used to work for a company that used to metal spray extruder screws with a had metal to increase life.

That was over 40 years ago when I worked in the UK
 

Blueboatman

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I am sure that- as ever- the OP will come back and thank all those who thoughtfully offered advice to his original question …. ?
Me, jokee?
 

Neeves

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I think you are saying the chain is 10 years old and the rusty portion has been 'used', but not live aboard 365 used, for 8 years and the 'clean' section has been used for 2 years (but it still 10 years old). The clean section looks good - which implies, considering history, that the galvanising was good. You used the first half for too long without end for ending

The rusty section looks good, no flaking.

I'm actually sure that the whole rode is good for another 1-2 years. The links look good. You are going to Patagonia, how long away from new chain....? its not the destination but the total time involved, 2 more years? So the worn chain is going to be exposed to corrosion for, maybe, 4 more years. I'd not take the risk and I'd buy new chain - chain is cheap, your yacht has a much higher value and I'm not putting a value on your marriage.

Or

I'd take it off NOW and have it regalvanised. The well used section looks good, the galvanising conducted originally looks good. Its the cost of regal now vs buying new chain. Any galvaniser will treat the chain and acid wash it, pickle it. Regalvnasing tend to be better than the original (so reported). Your regal chain will be as good as new, or better. I'd also guess your chain is oversized, how big is your yacht?

My options are new chain or regalvanising, its an unnecessary risk to ignore the background.

A good anchor allows you to relax, so does a reliable chain.

Jonathan
 
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NormanS

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I think you are saying the chain is 10 years old and the rusty portion has been 'used', but not live aboard 365 used, for 8 years and the 'clean' section has been used for 2 years (but it still 10 years old). The clean section looks good - which implies, considering history, that the galvanising was good. You used the first half for too long without end for ending

The rusty section looks good, no flaking.

I'm actually sure that the whole rode is good for another 1-2 years. The links look good. You are going to Patagonia, how long away from new chain....? its not the destination but the total time involved, 2 more years? So the worn chain is going to be exposed to corrosion for, maybe, 4 more years. I'd not take the risk and I'd buy new chain - chain is cheap, your yacht has a much higher value and I'm not putting a value on your marriage.

Or

I'd take it off NOW and have it regalvanised. The well used section looks good, the galvanising conducted originally looks good. Its the cost of regal now vs buying new chain. Any galvaniser will treat the chain and acid wash it, pickle it. Regalvnasing tend to be better than the original (so reported). Your regal chain will be as good as new, or better. I'd also guess your chain is oversized, how big is your yacht?

My options are new chain or regalvanising, its an unnecessary risk to ignore the background.

A good anchor allows you to relax, so does a reliable chain.

Jonathan
Oh Jonathan, why spoil a sensible discussion about condition of chain and the possibility of regalvanising, with your fetish about the size of chain related to the size of boat?
 

Neeves

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Oh Jonathan, why spoil a sensible discussion about condition of chain and the possibility of regalvanising, with your fetish about the size of chain related to the size of boat?
Nothing to do with a fetish.

Many yachts use chain that is larger then the chain recommended, the owners have a fetish and think large chain is better - but would struggle to provide a supporting argument.

If the chain is oversized then a reduction in link size by a few microns from corrosion is neither not there - that's not a fetish - its a fact.

But maybe I misunderstand your post

Jonathan
 

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Nothing to do with a fetish.

Many yachts use chain that is larger then the chain recommended, the owners have a fetish and think large chain is better - but would struggle to provide a supporting argument.

If the chain is oversized then a reduction in link size by a few microns from corrosion is neither not there - that's not a fetish - its a fact.
And a supporting argument, surely?
 

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YGSL have my chain at the moment. It's costing me £500 for 80m of 10mm chain and a 30kg anchor. They charge £2 plus vat per kilo. They blast it then regalv. Just off M1 at Rotherham. They aren't quick though. I have been waiting a month now
 

Neeves

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YGSL have my chain at the moment. It's costing me £500 for 80m of 10mm chain and a 30kg anchor. They charge £2 plus vat per kilo. They blast it then regalv. Just off M1 at Rotherham. They aren't quick though. I have been waiting a month now
I suspect they also pickle with acid.

Does that cost include delivery of the chain, both ways?

Jonathan
 

Neeves

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Hi.
No. I dropped it off and am picking it up on Wednesday.
Regards
Moving chain, especially 80m of 10mm chain is a thankless task - well done.

In a 'similar' exercise, we were down sizing the chan, I, unthinkingly, dropped (only) 50m of 8mm chain into a hefty plastic box in the dinghy and took it to the beach, nearby which our car was parked). I then realised packing it in one box was no use, I could not lift it. :)

Thanks Jules, let us know how it looks (a bit subjective I know) and in the fullness of time, say 2030 :), let us know how it performed

Jonathan
 

RunAgroundHard

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The next stage is scaling rust, about 6:1 ratio of flake build up to metal loss, ball park figure. As you have surface rust now, negligible loss of strength. The environment will be significant to the rate of scale development. It’s fair to say that warm, salt, damp could be an accelerator environment. If time is an issue, wash in fresh water, dry, and spray with a rust inhibitor like Rocol Z30 or Cortec VPCL 368. Coatings would only be useful for the chain that usually doesn’t get deployed, and you do not want to commit to regalvanising right now.
 

NormanS

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Moving chain, especially 80m of 10mm chain is a thankless task - well done.

In a 'similar' exercise, we were down sizing the chan, I, unthinkingly, dropped (only) 50m of 8mm chain into a hefty plastic box in the dinghy and took it to the beach, nearby which our car was parked). I then realised packing it in one box was no use, I could not lift it. :)

Thanks Jules, let us know how it looks (a bit subjective I know) and in the fullness of time, say 2030 :), let us know how it performed

Jonathan
I know what that's like.
Some years ago, when I had a big boat, I nosed in to the shore at HW, and dropped 45 Fathoms of 16mm chain on the beach. It's amazing what can be done with a car, a snatch block fastened to a tree, and a length of rope. Once it was regalvanised it was easy to pull it back aboard with the windlass.
 
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