Chain corrosion, beginning of the end?

[GEM43]

Hopefully this video link works:

The chain is five seasons old, it has been deployed 150 times. It is 8mm MF DAMS grade 70 chain.

This summer, for the first time, there is evidence of rust coloured deposits on the chain links, the rust rubs off easily as can be seen in the video.

Thoughts anyone? Is this chain on the way out?

 

[Stemar]

Surface rust is unsightly, but pretty much irrelevant to the strength of the chain. Yes, it'll get worse over time, and start leaving rust marks on your deck and in the locker (get rid of the stains with oxalic acid), but it's still got plenty of strength left. At this point, it may be possible to get it regalvanised. I've no experience of this, but I understand that places who'll do it are getting rare.

Eventually, you'll notice that the links are noticeably pitted, or they're getting thin on the tight where they rub together in use. That's when it's time to change it.

 

[vyv_cox]

The chain itself is perfectly OK. The only criterion is wear that would weaken it, this occurs at the contact points between links. The limit is 10% loss but yours appears to be about zero.

The galvanising is failing but this does not affect its strength. Re galvanising used to be the answer but this is increasingly uneconomical and many companies refuse to do it. However, several owners have used Yorkshire Spin Galvanising with success and not too expensive.

See Regalvanising chain for more information although, as said, much of it is historical.

 

[noelex]

Opting for thinner G7 means it will need to be replaced more frequently. The biggest issue is for yachts crusing and anchoring full time, similar to our vessel. 150 nights at anchor are racked up in only six months. However, you still have some life left before the rusting becomes a nuisance and replacement is needed.

 

[geem]

The chain itself is perfectly OK. The only criterion is wear that would weaken it, this occurs at the contact points between links. The limit is 10% loss but yours appears to be about zero.

The galvanising is failing but this does not affect its strength. Re galvanising used to be the answer but this is increasingly uneconomical and many companies refuse to do it. However, several owners have used Yorkshire Spin Galvanising with success and not too expensive.

See Regalvanising chain for more information although, as said, much of it is historical.

We used Yorkshire Spin Galvanising. I will report back in due course as to how good their galvanising is. As full-time liveabords, our chain gets way more abuse than most. In addition, in 3 months we will be in the Caribbean where the hot salty sea water is particularly corrosive. 3 years normally sees the end of life of our chain since galvanising in the Caribbean is not possible

 

[dpb]

Whilst not affecting strength, the rust on my 10mm chain eventually caused the chain to jam in the winch.

 

[geem]

Whilst not affecting strength, the rust on my 10mm chain eventually caused the chain to jam in the winch.

That's pretty rusty. I have never let my chain get to that level of corrosion before I replaced it because the little bits of rust that would break off whilst recovering the chain, caused rust spots all over the deck.

 

[doug748]

Hopefully this video link works:

The chain is five seasons old, it has been deployed 150 times. It is 8mm MF DAMS grade 70 chain.

This summer, for the first time, there is evidence of rust coloured deposits on the chain links, the rust rubs off easily as can be seen in the video.

Thoughts anyone? Is this chain on the way out?

I think it is an illustration of how poor the galvanizing is on some chain, I saw specks on some new stuff after one season. The previous re-galvanized chain had lasted about 15 seasons of summer use.
If your chain is full length, turn it end for end and you will prolong it's useful life......it becomes intolerable when it make such a mess of your deck you run out of patience.

.

 

[GEM43]

Thanks to all for your wise words, much appreciated. I’ll end for end it and have another five seasons of use out of it.

 

[Chiara’s slave]

We used Yorkshire Spin Galvanising. I will report back in due course as to how good their galvanising is. As full-time liveabords, our chain gets way more abuse than most. In addition, in 3 months we will be in the Caribbean where the hot salty sea water is particularly corrosive. 3 years normally sees the end of life of our chain since galvanising in the Caribbean is not possible

My knee jerk reaction is to ask if stainless chain would actually be more economic. As you’re, er, pretty experienced, I guess there’s a reason why this isn’t the case, or it’s unsuitable in some other way?

 

[geem]

My knee jerk reaction is to ask if stainless chain would actually be more economic. As you’re, er, pretty experienced, I guess there’s a reason why this isn’t the case, or it’s unsuitable in some other way?

The cost of s/s chain for us is £6000 last time I looked. We get 3 to 4 years out of the chain at less than £500 each time we replace our 60m length. I would love to have s/s chain but something like 25 year pay back. If I bought it now, I would no longer be sailing by the time it's paid for itself

 

[Chiara’s slave]

The cost of s/s chain for us is £6000 last time I looked. We get 3 to 4 years out of the chain at less than £500 each time we replace our 60m length. I would love to have s/s chain but something like 25 year pay back. If I bought it now, I would no longer be sailing by the time it's paid for itself

Thanks for that. Ours was a cheap reel end, since we only need a few metres.

 

[geem]

Thanks for that. Ours was a cheap reel end, since we only need a few metres.

Is that 316 or cromox? I am referring to cromox