Chain regalvanising.

[vyv_cox]

I have received this from an ex-colleaugue (last seen 30 years ago!)

I thought I’d give you some information on this as you state on your related page that BE Wedge no longer run their chain line - as part of my research I confirmed that they still don’t and neither does anyone else in the UK as far as I can ascertain; one Scottish company I called had a chain plant based in Elgin but that’s also now closed. After a lot of phoning around I found a company called Yorkshire Spin Galvanising (Yorkshire Spin Galvanising Ltd Home) who have a spin galvanising plant in Rotherham, Yorkshire. As I live to the west of Manchester it's not too far for me to drive to drop off and pick up my chain. Based on a phone call with them, I decided they seemed to know what they were talking about and have a process which sounded credible. They were incredibly helpful, provided a good service and great result for a fraction of the price of a new chain - their current pricing is £2 +VAT per kg of chain which includes shot blasting, acid cleaning, spin galvanising and manual for to endure all links are free moving. In my case the chain weights 126kg so that cost me about £300 compared with at least three times that cost for a new chain, and the galvanising is better that you see on most new chains. One good thing is that I didn’t need to clean off any of the paint or plastic cable ties which previous owners had applied for depth markings as the shot blasting dealt with it all!

 

[doug748]

Excellent news and an excellent price.

It would have saved a fair amount on the 50 mtr of new chain that I have recently bought. More importantly the galvanizing on the new chain looks very sketchy to me; back in the day I had two lots of chain redone and it both cases it lasted brilliantly.

.

 

[geem]

I have received this from an ex-colleaugue (last seen 30 years ago!)

I thought I’d give you some information on this as you state on your related page that BE Wedge no longer run their chain line - as part of my research I confirmed that they still don’t and neither does anyone else in the UK as far as I can ascertain; one Scottish company I called had a chain plant based in Elgin but that’s also now closed. After a lot of phoning around I found a company called Yorkshire Spin Galvanising (Yorkshire Spin Galvanising Ltd Home) who have a spin galvanising plant in Rotherham, Yorkshire. As I live to the west of Manchester it's not too far for me to drive to drop off and pick up my chain. Based on a phone call with them, I decided they seemed to know what they were talking about and have a process which sounded credible. They were incredibly helpful, provided a good service and great result for a fraction of the price of a new chain - their current pricing is £2 +VAT per kg of chain which includes shot blasting, acid cleaning, spin galvanising and manual for to endure all links are free moving. In my case the chain weights 126kg so that cost me about £300 compared with at least three times that cost for a new chain, and the galvanising is better that you see on most new chains. One good thing is that I didn’t need to clean off any of the paint or plastic cable ties which previous owners had applied for depth markings as the shot blasting dealt with it all!
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Great to know. I will get mine done there over the next winter. I guess they will do anchors as well?

 

[Neeves]

I have received this from an ex-colleaugue (last seen 30 years ago!)

I thought I’d give you some information on this as you state on your related page that BE Wedge no longer run their chain line - as part of my research I confirmed that they still don’t and neither does anyone else in the UK as far as I can ascertain; one Scottish company I called had a chain plant based in Elgin but that’s also now closed. After a lot of phoning around I found a company called Yorkshire Spin Galvanising (Yorkshire Spin Galvanising Ltd Home) who have a spin galvanising plant in Rotherham, Yorkshire. As I live to the west of Manchester it's not too far for me to drive to drop off and pick up my chain. Based on a phone call with them, I decided they seemed to know what they were talking about and have a process which sounded credible. They were incredibly helpful, provided a good service and great result for a fraction of the price of a new chain - their current pricing is £2 +VAT per kg of chain which includes shot blasting, acid cleaning, spin galvanising and manual for to endure all links are free moving. In my case the chain weights 126kg so that cost me about £300 compared with at least three times that cost for a new chain, and the galvanising is better that you see on most new chains. One good thing is that I didn’t need to clean off any of the paint or plastic cable ties which previous owners had applied for depth markings as the shot blasting dealt with it all!
View attachment 174291
View attachment 174292

I think Highland Galvanisers based in Cumbernauld and somewhere up north (I thought it was Inverness but might have been Elgin), they had 2 plants, might still be able to coat chain.

Geoff, of Knox anchor would be the one to ask, as he was MD of HG until he retired.

Jonathan

 

[AndrewB]

I've had Medway Galvanising Company Ltd do mine a few times, hot-dip regalvanising with shaking. Very satisfied with results. The cost was between one-quarter and one-third of new chain. Regalvanising doesn't seem to last quite as long as the original, maybe 5 years compared with 7 or 8 for new chain. It is essential the chain isn't showing serious rusting, no more than surface staining as in Vyv_Cox's pic.

 

[geem]

I've had Medway Galvanising Company Ltd do mine a few times, hot-dip regalvanising with shaking. Very satisfied with results. The cost was between one-quarter and one-third of new chain. Regalvanising doesn't seem to last quite as long as the original, maybe 5 years compared with 7 or 8 for new chain. It is essential the chain isn't showing serious rusting, no more than surface staining as in Vyv_Cox's pic.

Our chain goes rusty in 3 years. By year 4 there is no galvanising left. Chain is in constant use in between sailing.

 

[vyv_cox]

I've had Medway Galvanising Company Ltd do mine a few times, hot-dip regalvanising with shaking. Very satisfied with results. The cost was between one-quarter and one-third of new chain. Regalvanising doesn't seem to last quite as long as the original, maybe 5 years compared with 7 or 8 for new chain. It is essential the chain isn't showing serious rusting, no more than surface staining as in Vyv_Cox's pic.

I bought new chain in Corsica, quite rusty after three years. I had it regalvanised by BE Wedge, who applied 100 microns of zinc. That was in 2010 and, although quite rusty now, it has never been regalvanised again. We have missed a total of four years' use but it has been very well used in all other seasons.

 

[geem]

I bought new chain in Corsica, quite rusty after three years. I had it regalvanised by BE Wedge, who applied 100 microns of zinc. That was in 2010 and, although quite rusty now, it has never been regalvanised again. We have missed a total of four years' use but it has been very well used in all other seasons.

By the time we get back to the UK this autumn, our chain will be 2 years old. It will still have good galvanising, but I know by the following year it will be going bad. If we can get a better thickness of coating, I am hoping it will last a little longer. The chain will have been in constant use

 

[vyv_cox]

By the time we get back to the UK this autumn, our chain will be 2 years old. It will still have good galvanising, but I know by the following year it will be going bad. If we can get a better thickness of coating, I am hoping it will last a little longer. The chain will have been in constant use

Yes, yours gets twice the exposure that ours does as seasonal sailors.

 

[geem]

Yes, yours gets twice the exposure that ours does as seasonal sailors.

How much do you think the fact that the sea water temperature has been between 27 and 33 degC, sijce we have owned the chain, impacts on the rate of corrosion?

 

[Neeves]

The galvanising is removed by abrasion not through corrosion (unless you anchor in anaerobic mud in which case the acidic nature of the mud will corrode the gal). Once the gal has gone, or goes in places, then the corrosion of the unprotected steel will commence and you are losing 'chain'. Reading posts from long term cruisers a 4 year life is possible - but no longer. Shorter would not be unexpected. Gal life, being due to abrasion, is determined primarily by gal thickness and most galvanising is around 70 microns - but it does vary. You cannot increase gal thickness beyond about 100 microns as at this thickness the alloy layer, at the original steel interface, breaks down and the gal peals off. Gal demands clean steel to adhere and if the steel in not cleaned, normally with acid but sometimes (and to remove paint) grit blasting), then (again) you will not develop a robust gal/steel interface.

I have seen no data but would expect corrosion, when the gal has been abraded completely (in whole or in parts), to be of an increased rate in warmer water.

For most people who only anchor intermittently they can increase gal life by washing their chain in fresh water, ensuring any rope (which inevitably will be damp) is kept away from the chain and airing (drying) the chain locker. New chain has a surface of pure zinc - this is protective but is subject to white rust (google it) and IS your zinc dissolving. So....when you wash the deck with fresh water - wash the chain in the locker and ensure the locker drains allow water to drain freely. If possible add a false bottom to the locker to ensure the chain does not sit in a puddle of water. Lift the hatch/lid of the chain locker to allow the drain to dry. To be contradictory - if its teaming down with rain - open the locker right up and allow the rain (which will be soft water) to rinse the chain.

If you are buying new chain Vyv has a neat test to determine the adhesion of galvanising - which I think is on his website.

If you are having chain regalvanised you are in a position to ask for extra thickness but most chain is galvanised to a 60 or 70 micron thickness - which is a standard for engineering products, like steel construction components (that are never subject to abrasion and last for decades). We have a galvanised steel platform on which our car sits - its now 25 years old and has no rust at all (and we are within 100m of the sea).

Our chain locker had a flat based which we filled with rubber door mats. The retrieved chain could freely dry and the locker drained from front to back.



If your locker does not drain you can expect your chain to corrode. This was a new yacht at a boat show - would you buy a yacht from this exhibitor?



Once you have worn the gal away the underlying steel will show through and as you retreive after anchoring over night the steel will be shiny, but remaining gal more matt. You will see no signs of rust - as it will have been abraded off as the chain sweeps the seabed. So look for the shiny steel, Don't think because there is no rust you are not wearing your chain - the gal is actually harder than the steel and once the gal goes your chain, the steel will thin more quickly than you lost the gal.

From memory which may be jaded - gal has the harness of HT steels which is 2 to 3 times the hardess of most steels used for chain G30 vs G100. The gal on HT steels (say G70 and up) is no better or worse than the gal on a common G30 chain - hardness of the underlying steel has no impact on the abrasion resistance of the galvanising - I've tested it (number of times).

Hardness and abrasion resistance are interrelated - again its been tested.

Its all about gal thickness - simple stuff. The hardness of the steel is only relevant when all the gal has gone.

Jonathan

 

[Neeves]

White rust

Wet Storage Stain (White Rust)

J

 

[Neeves]

This is an example of Vyv's galvanising test. Cut a link off, put the bottom half of the link in a decent vice and twist the rest of the link through 180 degrees - the gal is well adhered. Because I cut the length opposite the weld - the test also checks the integrity of the weld (the weld should be stronger than the wire).

Below is a different take on a similar test. I have tested the chan to destruction and the chain has stretched. The gal has peeled off - not good. Poor alloy formation. It looks good the top link - but the reality is different. If you do not test it - you would not know.



I was testing a chain hook. The chain is a 6mm G30 and the chain hook has caused the chain to fail prematurely. Though the chain has failed and distorted the gal has remained intact. The chain was good - the hook not fit for purpose (and has been withdrawn)

To make Vyv's test you could actually do it in the chandlers car park - if they will let you cut off one link and you take the necessary kit with you. Given the cost of chain and the simple fact that the gal determines the life of the chain - its worth doing.

Jonathan