New anchor chain. HELP!!

[No Ice]

Well one year ago you all helped me to buy my new anchor and shakles and last summers cruising in Croatia proved you all right so im back again to draw on your collective knowledge.

My 10mm chain is 12 years old and rusty in several places, i have 100 M of galvanised chain G30 i think and i want to change it but to what? this is the question!

Im in Italy so think europe please.

I would like to use stainless steel because i could keep to 10MM and use my windlass which saves a few bob. (english exspression)

What do i need to know and consider in makng the choice.

Hope your wealth of Knowledge can help again.

Brian
No Ice

[Stu Jackson]

Why stainless?

[No Ice]

Hi Stu

I want stainless because its stronger than galvanised steel and i need to keep the chain size at 10 mm to fit my gypsy.
y boat weighs 23 tons fully loaded and my anchor is a 40 KG Rocna

No Ice

[sailsw00]

Brian:
If you change from 10 mm you will probably need a new gypsy, and that will raise the cost. Why not stay with 10 mm galvanized? I believe it's stronger than stainless and you won't have corrosion problems with your anchor.
The next question, though, is the spec of the 10 mm galvanized: G-30, G-40, or G-70? I would suggest a number of recent articles in recent issues of Practical Sailor magazine to answer that question.
-Steve (aka sailsw00)

[roverhi]

Chain is not the same. The stainless may not be the same link length as the galvanized so may not work in your chain gypsy. Personally would go with G40 galvanized chain in whatever size fits your gypsy. Doubt that SS chain is stronger than G40 galvanized. 10MM G40 galvanized chain should be plenty strong for a boat with your displacement.

Is the galvanizing just gone on the chain or is it rusty to the point that the links have lost significant diameter?? If the chain has just lost the galvanizing might think about getting it regalvanized. You'd have to find a galvanizer that can do chain and transport it to them but it would give you a long life extension for a lot less money.

[Sailmonkey]

Stainless may seem stronger in an anchor chain.....then it suddenly isn't.


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[banjoship]

Originally Posted by Sailmonkey

Stainless may seem stronger in an anchor chain.....then it suddenly isn't.

Translation for the OP: stainless work hardens under the everyday snatch and jerk that a rode and its links are subject to. Eventually the stainless can weaken to a point where it snaps under load.

I would not have any stainless components in my anchor rode. Earlier posters have suggested the merits of going all gal.

Lee


Edit: You will not find any rated industrial lifting equipment in stainless, for the above reason.

[a64pilot]

I don't think typical stainless, say 304 is as strong as most carbon steels, say 4130.
Pretty sure galvanized high strength steel chain is significantly stronger than stainless?

[noelex 77]

10mm chain is readily available in galvanised chain. You can get G30, G40, G50 and G70. The higher numbers are stronger. G70 10mm is roughly as strong as G30-40 12mm.

Maggi are very respected chain makers and are Italian, where you are located. They sell G40, G50 and G70. Just beware that they generally make chain to order. Don't believe their promised delivery time!

In stainless steel there are a couple of choices. 316L is reasonably readily available. If you search around, G50 and Duplex SS chain are also available. If you look at the German SVB website they sell Duplex SS. People love or hate SS chain. There are enough horror stories to make me wary. Crevice corrosion is a problem. However, well made Duplex SS should be fine.

Anchoring full time I can only get about 4 years out of galvanised chain even reversing it after 2 years, so SS has some appeal. Anchoring part time in softer substrates a 12 year or greater life is common and I think galvanised chain is overwhelmingly the best choice. The exception is those boats that have a marginal chain drop from the windlass. Here the slippery nature of SS does help reduce the size of pyramid and can mean the chain feeds without having to manually push it down. It also comes up a bit cleaner after anchoring in mud.

There are two types of metric 10 mm chain with different link sizes often called DIN and ISO. Most gypsies will only work with the correct type. Fortunately, unlike imperial chain, the link size does not change as you alter materials. So DIN 10mm G30 is the same link size as DIN 10mm G40, or G70. Likewise, DIN stainless steel 10mm chain is also the same link size. So you can change between different materials and strengths without problems as long as you don't switch between DIN and ISO.

Be careful, as it is easy to end up with the wrong sized 10mm chain. Check the link size of your current chain and make sure what you buy is the same. Here is a good website with the different chain dimensions:
https://coxengineering.sharepoint.co...finitions.aspx

[noelex 77]

Incidentally, if you are buying new chain the website:
https://coxengineering.sharepoint.co...finitions.aspx

Has some easy tests that you can do yourself on a sample the chain. You only need a vise and a hacksaw.

The tests help determine the quality of the galvanising and the strength of the welds.

Brilliant

[rwidman]

Originally Posted by No Ice

Well one year ago you all helped me to buy my new anchor and shakles and last summers cruising in Croatia proved you all right so im back again to draw on your collective knowledge.

My 10mm chain is 12 years old and rusty in several places, i have 100 M of galvanised chain G30 i think and i want to change it but to what? this is the question!

Im in Italy so think europe please.

I would like to use stainless steel because i could keep to 10MM and use my windlass which saves a few bob. (english exspression)

What do i need to know and consider in makng the choice.

Hope your wealth of Knowledge can help again.

Brian
No Ice

You got twelve years out of the galvanized chain. If the rust bothers you or you think it has weakened the chain, the simplest thing to do is replace it with identical galvanized chain. You should get another twelve years out of it.

[Bulawayo]

I would avoid stainless steel anchor chain. Galvanised chain shall distort before failing - stainless steel just lets go and crevice fractures an be near impossible to detect. Check Practical Sailors article and advice - they recommend NOT using stainless steel.
Some have the opinion that stainles steel does not rust - it does!

[Terra Nova]

No way would I trust stainless chain.

[Cadence]

You are misinformed about stainless. It does not have a higher tensile strength . Go back to what you had. If it rusts replace it, probably cheaper and stronger in the long run.

[No Ice]

Well you all are against stainless chain. Thanks for all your thoughts, you guys sorted me last time and you've done it again. I'm off stainless and talking to Maggie here in Italy about their Aqua 7 chain which is a lot stronger than the 30 or 40. Now my problem is which size is my windlass gypsy. They sell chain in 2 sizes 10x28 and 10x30.

Any advice on how I can determine what I have. My original chain was supplied with the boat in Italy back in 2003 it was galvanised and that's all I know.

Any suggestions?

Brian


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