Galvanised Chain vs Stainless Steel and Swivels

[impi]

Hi there felow sailors,

We are almost set for our world cruise but are confused about chains and anchors.

I currently have about 80meters of Glavanised chain and 40 meters of line.
We have 12-13mm chain (which is heavier ? than most for our 45 foot cat) and after dragging our Delta Anchor around the bay in 40 Knts have purchased a 33KG Rocna - Galvamised.

The supplier suggested I buy a swivel which I duely did, but the swivel is Stainless steel and I was advised by fellow sailors that there is a chemical reaction that will cause failure between stainless and galvanised.

I then looked at the SVB catalogue to see what it would cost me to import stainless chain of good quality.
Further confusion in my mind now - as there they suggest in waters that are warm such as Carribbean and med, one should choose a good quality galvanised chain over stainless ???

Please could you advise me if it is ok to stick with my galvanised chain - if so - Does one get a Galvanised swivel of GOOD Quality?
Is stainless preferable over Galvanised?

[estarzinger]

Originally Posted by impi

Please could you advise me if it is ok to stick with my galvanised chain - if so - Does one get a Galvanised swivel of GOOD Quality?
Is stainless preferable over Galvanised?

That should be a perfectly secure ground tackle system - good anchor, and quite heavy chain. Swivel is ok but you really probably don't need it. You are good to go!

Yes, you can stick with your galvanized chain - that's fine.

And you can also stick with your stainless swivel. In theory there could be some pitting of the swivel, but in practice you will not notice anything. Most cruisers will say you don't need the swivel at all.

[impi]

Originally Posted by estarzinger

That should be a perfectly secure ground tackle system - good anchor, and quite heavy chain. Swivel is ok but you really probably don't need it. You are good to go!

Yes, you can stick with your galvanized chain - that's fine.

And you can also stick with your stainless swivel. In theory there could be some pitting of the swivel, but in practice you will not notice anything. Most cruisers will say you don't need the swivel at all.

Thanks for the speedy reply - Im curious about the 'in theory' comment and 'some pitting' - Is this a hazard or is it something that causes deterioration over a number of years?

Im pleased to hear the swivel is not necessary and think I will chuck that for my current system. Are the galvanised shackles strong enough?

[doug86]

Swivels are not needed and only add an extra weak link

[impi]

What is the idea of swivels then?

[estarzinger]

Originally Posted by impi

Im curious about the 'in theory' comment and 'some pitting' - Is this a hazard or is it something that causes deterioration over a number of years?

Are the galvanised shackles strong enough?

Some of our metallurgists can probably explain much better, but my kindergarten explanation is that stainless underwater, not exposed to oxygen can experience depassivation of a small area, which becomes anodic while the broader area becomes cathodic causing localized galvanic pitting. It definitely happens to stainless that sits underwater for long periods, but does not seem to happen (much) to anchor swivels that are raised and lowered regularly.

Properly sized (biggest that will fit thru the end link) and proofed galvanized shackles will be well strong enough. That's pretty big chain (compared to the anchor), so you will easily be able to fit a a decent size shackle.

[doug86]

Originally Posted by impi

What is the idea of swivels then?

I have no idea. You tell me. What is their purpose? 20 years of anchoring, never had one.

[svpresent]

Originally Posted by impi

...Further confusion in my mind now - as there they suggest in waters that are warm such as Carribbean and med, one should choose a good quality galvanised chain over stainless ???

Please could you advise me if it is ok to stick with my galvanised chain - if so - Does one get a Galvanised swivel of GOOD Quality?
Is stainless preferable over Galvanised?

My advice would be: stay away from stainless steel chain. Ok, they flow nicely into your chain locker but... I have seen cases of ss chain completely desintegrating from inside out in 2-3 years. This even happens to the well known brands.

There is nothing better then good quality steel, properly galvanized. In the Caribbean a chain like that will last 4 to 5 years, in my experience.

I use a stainless steel swivel. For one I want to be able to rotate the anchor with ease when pulling in. So I have a galvanized chain, a stainless Wasi swivel and a galvanized cqr. My second anchor is a aluminum Spade, same chain, same swivel. I regularly check the stainless bolts in the swivels that touch the chain and anchor and since I mounted it in 2005, there is no change or whatever damage to be seen.

Have fun and fair winds!
Len.

[trinescape]

IMPI you do need that swivel on your chain, multihulls move around alot more on the pick than monohulls do, i think the term is called sailing around your anchor which twists the anchor chain, my 36 ft tri suffered from kinking in the chain (3/8 galv )which would knot up on my gypsy, a fellow multihull cruser put me onto the stainless swivel and i no longer have this problem infact its been on now for 4years and there is no pitting or corrosion evident believe me its worth keeping it on cheers andy

[impi]

Originally Posted by trinescape

IMPI you do need that swivel on your chain, multihulls move around alot more on the pick than monohulls do, i think the term is called sailing around your anchor which twists the anchor chain, my 36 ft tri suffered from kinking in the chain (3/8 galv )which would knot up on my gypsy, a fellow multihull cruser put me onto the stainless swivel and i no longer have this problem infact its been on now for 4years and there is no pitting or corrosion evident believe me its worth keeping it on cheers andy

Thanks for that - I have been told that the metal deteriorates from the inside out so it is not always visible damage that one sees. What conserns me is the day it decides to give up. Im not sure if the galvanised link gets influenced or the stainless swivel or perhaps both?

[impi]

Originally Posted by svpresent

I use a stainless steel swivel. For one I want to be able to rotate the anchor with ease when pulling in. So I have a galvanized chain, a stainless Wasi swivel and a galvanized cqr. My second anchor is a aluminum Spade, same chain, same swivel. I regularly check the stainless bolts in the swivels that touch the chain and anchor and since I mounted it in 2005, there is no change or whatever damage to be seen.

Have fun and fair winds!
Len.

Thanks Len,

I have seen the Wasi, and have been told the Wasi is a superior swivel.

Does one not get a galvanised swivel?

[impi]

Originally Posted by estarzinger

Properly sized (biggest that will fit thru the end link) and proofed galvanized shackles will be well strong enough. That's pretty big chain (compared to the anchor), so you will easily be able to fit a a decent size shackle.

Thanks - excuse my ignorance but what is a 'proofed galvanised shackle' ?

[svpresent]

Originally Posted by impi

Thanks Len,

I have seen the Wasi, and have been told the Wasi is a superior swivel.

Does one not get a galvanised swivel?

My boy scouts explanation would be that a swivel consists of moving parts so the thin coat of zinc will disappear quite soon on the spots where the moving parts touch. The zinc coat will disappear from your chain as well but that takes years.

What is your planned route?

Cheers,
Len.

[impi]

Originally Posted by svpresent

My boy scouts explanation would be that a swivel consists of moving parts so the thin coat of zinc will disappear quite soon on the spots where the moving parts touch. The zinc coat will disappear from your chain as well but that takes years.

What is your planned route?

Cheers,
Len.

Thanks Len, Makes sense.

We plan on crossing the Atlantic to Brazil (leaving July - been delays due to selling my business and finding a tenant for the farm), up to and through the Carrib to Southern Bahamas, down to San Blas, through the Panama Canal, past Galapagos and spend quite some time around French Polynesia. Thats the plan anyway ...

[svpresent]

Originally Posted by impi

Thanks Len, Makes sense.

We plan on crossing the Atlantic to Brazil (leaving July - been delays due to selling my business and finding a tenant for the farm), up to and through the Carrib to Southern Bahamas, down to San Blas, through the Panama Canal, past Galapagos and spend quite some time around French Polynesia. Thats the plan anyway ...

Ah, Brazil, excellent choice. We went from Gambia to Brazil in 2008. Didn't want to go that far south with the boat so we stayed in this nice little harbour for 6 months (6 months is maximum and Brazilian Immigration is quite strict):
Marina Jacar Yacht Village
Definitely not high end but safe, friendly people. Friends got their outboard stolen in Natal. We left the boat in Jacare for exploring South America. Had a great time.

Cheers,
Len.