Anchor to chain connector

[DavidGrieves]

Hi All

I have a galvanised anchor and galvanised chain, the connector is a straight stainless steel type. How bad will this be regarding galvanic corrosion? When I look round the marina there a quite a few with the same setup.

Any amateur metallurgists out there to offer any advice?


Cheers

 

[Sneaky Pete]

During my recent boat survey this was raised by the surveyor he suggested that the shackle should be changed to a galvanised type bow shackle. So for a couple of quid it was changed.

 

[TradewindSailor]

You don't say whether the stainless connection is a swivel or a shackle.

If it is a swivel, I would put a short length of galvanised chain between it an the anchour, mainly to reduce any out of line stress on the swivel, but also to create some corrosion protection for the anchour. The galvanising will thin most in immediate proximity of the stainless steel. The stainless will tend to get coated with zinc that would reduce the rate of galvanic corrosion. Chopping off the rusted links each season should not be a big problem.

If it is a shackle just change to the largest and best quality galvanised one you can find ..... and definitely NOT the cheap rubbish you get in DIY stores that are generally made in China.

You must of course tie any pins off with wire ..... preferably monel, although I have used polyester lashings before now.

 

[vyv_cox]

There is a great deal of information about this on my website.
Firstly on the corrosion - an anchor is not immersed for long enough for any galvanic effects to emerge. After about three years of normal use the zinc will be lost from the last couple of chain links but otherwise no problems.
Secondly, when I did the tensile tests shown on the website stainless shackles came out as generally being far stronger than galvanised ones. Some of the latter were very poor indeed.

 

[macd]

Any amateur metallurgists out there to offer any advice?

Nah, mate. Only professionals on 'ere (see above)

 

[davidfox]

Hi All

I have a galvanised anchor and galvanised chain, the connector is a straight stainless steel type. How bad will this be regarding galvanic corrosion? When I look round the marina there a quite a few with the same setup.

Any amateur metallurgists out there to offer any advice?


Cheers

I have this set up, not ideal i know, but i could not get a galvansied articulated connector big enough at the time. It has lasted 6/7 years but of course the last 4 or 5 links of chain have rusted more than the rest, although the anchor appears reasonably unscathed. I treated the anchor and chain to a zinc rich paint this year (zinguard) and whilst doing so cut off the rustier links, i sprayed the stainless connector with the zinguard as well, dont know what that will do, but it may choose to corrode that rather than the galvanising on the chain?

 

[rivonia]

Vic's reply says it all. We have a S/S swivel between the anchor and chain. No probs at all

 

[vyv_cox]

Nah, mate. Only professionals on 'ere (see above)

Are there any amateur ones? I don't envy anyone trying to learn it at home from text books. As usual with education, I have forgotten 90% of what I learned but the other 10% comes in handy.

 

[DavidGrieves]

Nah, mate. Only professionals on 'ere (see above)

Would that be "Manx Jig"? Dr ?

Just read your profile, not who I thought you were. Met a guy in Ramsay last year who has a Legend 35 I think he keeps it in Prezeza(sp) I did the Ionian Regata a couple of years ago, great fun. Have you done it?

 

[akyaka]

Have never had any problems with galvanic action and we anchor a lot . Following the advice on Vyv's web site we have 4 links between our stainless steel swivel connector and the anchor . Mind have seen some dodgy cheap swivel connectors around. We have a Kong.

 

[robertj]

I indeed took the advice of young vyv and can say that we haven't had any problems at all.

 

[macd]

Would that be "Manx Jig"? Dr ?

Just read your profile, not who I thought you were. Met a guy in Ramsay last year who has a Legend 35 I think he keeps it in Prezeza(sp) I did the Ionian Regata a couple of years ago, great fun. Have you done it?

Sorry, I'm not that distinguished chap. Don't do Manx jigs, although have been known to reel occasionally.
Haven't done the rally, either. Now you're making me feel inadequate...

 

[KellysEye]

We had a galvanised shackle. Having seen three charter boats on the rocks in Greece when their swivels broke I wouldn't fit one.

 

[vyv_cox]

We had a galvanised shackle. Having seen three charter boats on the rocks in Greece when their swivels broke I wouldn't fit one.

There are good and bad swivels, as with most things. The worst of all are just two circular links with a bolt holding them together, all the load coming on the nut screwed onto the bolt. At the other end of the scale you have Kong and Osculati, cleverly designed so that no screwed connection carries any anchor load. There are many in between, some not so good, some not so bad. Buy sensibly and you will have no problem. My windlass instructions recommend a swivel.