New anchor chain in Duplex stainless

[Duplexity]

I have a 10 mm / 50 meter (G40 I believe) galvanized chain and I have had some problems from the beginning which means when winching up anchor chain it starts building tower in anchor box and chain sometimes stops falling down. When this happens my windlass (Lofrans' X2) will be blocked and sometimes I need tools and to demount a part of windlass to release chain. (Not funny if short handed in windy and narrow harbors and you can't get anchor up..)

After six seasons since new (5-6 weeks a year sailing) chain has start to rust and problem has been serious with chain not flaking down in anchor box and windlass blocked.

I have decided to not regalv the old one and instead buy a good quality chain. I have founded two options in grade 70 and grade 60, why I could go for 8 mm chain and at the same time 60 meter instead of 10 mm / 50 m. (Aqua4 10 mm has breaking load 63 kN and price for 10mm/grade40 is more or less same as 8mm/grade70).

1. Maggigroup (made in Italy) Aqua7, grade 70, galvanized (BRL 70 kN, 8 mm)
2. Ketten Wälder (made in Germany) Stainless 318L Duplex, grade 60 (BRL 63 kN, 8mm)

Price for 8mm / 60m Duplex including shipping to Greece is 3 times more (option no1 vs no2)

Advise and question to everybody out there...
I know the "problem" with stainless anchor chain in 316L / grade 40 (or less quality) when anchoring longer periods in mud could create quick corrosion. Some also argue if surface will be scratched then the protective oxide skin is damaged and corrosion will start. But all this discussions is about "standard" stainless and not about Duplex (318L) quality.

Does anybody have experience of Duplex quality? Is it a major difference between 316L and 318L and should I not expect any corrosion problems when using Duplex in the Med (22 -27 degrees sea water).

What I understand Aqua7 is quite new at the market, but you could have both galvanized and stainless in different grades which means different breaking load. Simply if you go up in grade you could go down in size. I think this is a smart move to go from 10 to 8 mm regarding cost, weight and space in anchor box. What do you think?

Of course I need to change my gypsy but I will still hang on with my galvanized anchor (20 kg, Delta by Lewmar). I have a performance s/y 45 feet and stowing place for chain is maybe somewhat narrow / limited (vs a true cruiser yacht) which may explain why my experience differ from yours.

[seandepagnier]

I have never seen anyone with duplex anchor chain, but it is certainly a much better alloy to use than 316. If it is good enough, I am not really sure, because I believe it is not completely immune to crevice corrosion, so could at some point fail without notice.

If you don't like rust, what about anchoring using line? I have met someone who uses nylon line all the time in the tropics without issues, and basically, it is much lighter and easier to handle, cheaper, and can stretch to absorb waves unlike chain.

Otherwise, you could try titanium chain, but would probably be too expensive.

[GordMay]

Greetings and welcome aboard the CF, Duplexity.

[John Boor]

Before doing any purchases I would look into why the chain is rusting so quickly. My first concern is the piling of the chain, to me this indicates that the chain fall is not enough. when my windlass was installed the manufacurer suggested a minimum 1mtr fall, do you have this and do you have good drainage from the anchor locker.

john

[colemj]

Both of the chain manufactures you are considering are among the best and produce highest quality products.

Aqua7 isn't really a new product for Maggi - they just gave their old G70 product a new name - same with Aqua4. It is an established product with an excellent reputation.

Duplex is the only type of stainless chain I personally would be comfortable with - and would probably have it except for the cost.

Mark

[suenodelmar]

You might save a lot of money by not buying stainless chain and a new gypsy but by modifying your current system with galvanized chain. The problem with galvanized chain in a locker is that it piles high, at a steep angle, and blocks the windlass. It does not spread out very much. Galvanized chain in a chain locker looks more like the Eiffel Tower than like a flat lake. A well-designed chain storage system needs to have a minimum of one foot between the top of the chain pile and the bottom of the hawes pipe that the chain falls from. When the top of the pile reaches the bottom of the hawes pipe, the chain backs up and blocks the windlass. Before spending a lot of money to buy stainless chain, which flows into the chain locker and forms a lake rather than the Eiffel Tower, try this possible solution: Get a small plastic traffic cone, like the orange-colored plastic cones used near roadside construction projects. Attach the cone to the bottom of the chain locker so that the top of the cone is directly underneath, and at least one foot below, the opening of the hawes pipe. If necessary, cut the base of the cone to maintain the minimum one-foot separation. In use, the cone should cause the chain to spread out, filling more of the chain locker and reducing the height of the pile.

[Mike Banks]

I think you are better to use a heavy chain but shorter length--and use heavy nylon 20mm rode and a 10KG kellet in the event of a storm.

I use a kellet (weight used suspended from the anchor chain--effectively doubles the holding power of an anchor is storm conditions) made from a 10KG sports barbell--with a big galvanised eye bolt fastened through the hole with a couple of heavy washers and square nuts fixed in place with Araldite and the thread burred over. On the shank of the eye bolt fit first a nut, then heavy washer, spacers if be=necessary , then barbell weight, another heavy washer, then another nut. Fasten the bottom nut at the bottom of the bolt with Araldite, and when cured, beat over the end of any protruding threads and adjust the tightness of the barbell with the top nut. I got my bolt about four hundred millimetres long from a scrap dealer, galvanized, cost me only a few dollars. I think it came from a power transformer originally. I cleaned it with a wire brush, dipped the base in acid, then tinned it. The whole thing cost me about twenty-five dollars if you count the yellow paint.

If you are losing the galvanizing from your anchor chain you are probably using an electric anchor winch with a single pole relay. Use a two pole relay (or two separate relays), because if not then your galvanizing and chain is connected to the negative of your battery--and has become an additional sacrificial anode to your through hulls and propeller. I lost most of the galvanizing from my chain and an anchor before I found out about this OBVIOUS but usually overlooked problem.

Incidentally--I set my kellet according to the depth of water, for obvious reasons. As soon as the weight comes off the chain, reach down with a boat hook and pull some of it aboard. Fit the tail of the kellet (about a metre of chain) and shackle it to the main chain rode, making sure you have done it by pulling back a little chain so it goes overboard and is not jammed in the bow hawse roller. NEVER fit the kellet shackle into the nylon rode--it will chew it through in only a short time--nylon needs to be taut so it remains standing clear of the bottom--and putting a kellet on it will ensure it is dragged backwards and forwards over whatever bottom you have--none of which is good for rope.

Incidentally--I think your anchor is the MINIMUM I would use on a boat 45 feet long with about four or five ton, maybe more, of extra ballast. A kellet is ESSENTIAL in a storm situation with such an anchor--and I would use heavier---my own vessel uses such an anchor weight and mine is half the weight of yours--it is the backward surge under wave conditions that pull anchors out of the mud or snaps chains or pulls out deck hardware--and the heavier the vessel, the more likely it is to happen. Nylon rode plus heavy chain and a kellet (or Angel as some of the old timers called them) makes the surges smooth and less likely to damage anything.

[Greggegner]

Originally Posted by suenodelmar

You might save a lot of money by not buying stainless chain and a new gypsy but by modifying your current system with galvanized chain. The problem with galvanized chain in a locker is that it piles high, at a steep angle, and blocks the windlass. It does not spread out very much. Galvanized chain in a chain locker looks more like the Eiffel Tower than like a flat lake. A well-designed chain storage system needs to have a minimum of one foot between the top of the chain pile and the bottom of the hawes pipe that the chain falls from. When the top of the pile reaches the bottom of the hawes pipe, the chain backs up and blocks the windlass. Before spending a lot of money to buy stainless chain, which flows into the chain locker and forms a lake rather than the Eiffel Tower, try this possible solution: Get a small plastic traffic cone, like the orange-colored plastic cones used near roadside construction projects. Attach the cone to the bottom of the chain locker so that the top of the cone is directly underneath, and at least one foot below, the opening of the hawes pipe. If necessary, cut the base of the cone to maintain the minimum one-foot separation. In use, the cone should cause the chain to spread out, filling more of the chain locker and reducing the height of the pile.

This is a good idea, stainless chain will just be a prettier tall pile...smaller chain would also help a lot but try the $10 solution first.


Greg S/V Sweet Dreams
Pearson P385 out of Racine Wisconsin

[Tayana42]

The traffic cone didn't work for me. I found a partial solution by cutting a 4" hole next to my Hawke pipe and putting in a deck plate to close it. When the chain starts to pile up I can reach in and knock the pile over. That worked okay. After a couple of years I had another project reworking the drainage from the chain locker during which I lowered the floor of the chain locker about a foot. That completely solved the problem.


S/V B'Shert

[colemj]

Originally Posted by Greggegner

This is a good idea, stainless chain will just be a prettier tall pile

Our experience with stainless chain is that it does not pile up at all - it all falls to the lowest point of the locker and won't reach back to the windlass until the locker is literally full of chain.

Mark

[Duplexity]

Thanks for all comments and advice!
Sometimes design overcomes function..
My anchor is deployed at an anchor arm which when not in use folding backwards and down in anchor locker. When sailing or not using anchor, deck is clean and no ugly anchor hanging at the bow. You would love the design! But for sure the design is not the best for using windlass and with some rust at chain I have a mess with the chain.

The design of anchor box is first an open space (for anchor swung back below deck), then a watertight stowage area with hatch at top and below this stowage is the chain storage and I estimate it's only 40 cm / 1.5” high. The chain comes down (about 1 m) at the side of this storage area and it's only a small hatch in the bottom of stowage area to the chain storage. Chain is at the very bottom of the hull and this area is equipped with an automatic bilge. It’s not easy to help chain to not pile up when using windlass (=very limit access to chain storage).

I have a plan to redesign chain storage and make it bigger (take some space from stowage area). But even though I will make it bigger, it will not be space for a plastic-traffic-cone to avoid chain pile up.

My opinion is that corrosion of my galvanized chain started during last winter (the 6th) on land and I have to admit I didn’t storage in the best way (chain down in the locker). I have been at shipyard in Greece last winter seasons and I have seen everybody storage chain outside on ground (and with funny rat traps of plastic bottles placed at the chain up to the bow). I don't believe in electric-galvanic current from windlass in my case (but I will check it up - my windlass). I can’t change anchor due to it's the only which will fit in anchor box. And I'm happy with my 20 kg delta to my 10.5 ton yacht (I have two spare anchor and a lot of ropes (4x50m) and chain to use as extra in tuff conditions). I believe chain works much better than rope in windlass.

I assume conclusion should be for me (with limited space of chain storage):
Pay and be happy with Duplex stainless, it flakes better and will not corrode. I have already realized, yachting is not the cheapest hobby you could have. But the most wonderful...

[poiu]

Originally Posted by Duplexity

I have a 10 mm / 50 meter (G40 I believe) galvanized chain and I have had some problems from the beginning which means when winching up anchor chain it starts building tower in anchor box and chain sometimes stops falling down. When this happens my windlass (Lofrans' X2) will be blocked and sometimes I need tools and to demount a part of windlass to release chain. (Not funny if short handed in windy and narrow harbors and you can't get anchor up..)

After six seasons since new (5-6 weeks a year sailing) chain has start to rust and problem has been serious with chain not flaking down in anchor box and windlass blocked.

I have decided to not regalv the old one and instead buy a good quality chain. I have founded two options in grade 70 and grade 60, why I could go for 8 mm chain and at the same time 60 meter instead of 10 mm / 50 m. (Aqua4 10 mm has breaking load 63 kN and price for 10mm/grade40 is more or less same as 8mm/grade70).

1. Maggigroup (made in Italy) Aqua7, grade 70, galvanized (BRL 70 kN, 8 mm)
2. Ketten Wälder (made in Germany) Stainless 318L Duplex, grade 60 (BRL 63 kN, 8mm)

Price for 8mm / 60m Duplex including shipping to Greece is 3 times more (option no1 vs no2)

Advise and question to everybody out there...
I know the "problem" with stainless anchor chain in 316L / grade 40 (or less quality) when anchoring longer periods in mud could create quick corrosion. Some also argue if surface will be scratched then the protective oxide skin is damaged and corrosion will start. But all this discussions is about "standard" stainless and not about Duplex (318L) quality.

Does anybody have experience of Duplex quality? Is it a major difference between 316L and 318L and should I not expect any corrosion problems when using Duplex in the Med (22 -27 degrees sea water).

What I understand Aqua7 is quite new at the market, but you could have both galvanized and stainless in different grades which means different breaking load. Simply if you go up in grade you could go down in size. I think this is a smart move to go from 10 to 8 mm regarding cost, weight and space in anchor box. What do you think?

Of course I need to change my gypsy but I will still hang on with my galvanized anchor (20 kg, Delta by Lewmar). I have a performance s/y 45 feet and stowing place for chain is maybe somewhat narrow / limited (vs a true cruiser yacht) which may explain why my experience differ from yours.

The Maggi chain looks good to me and enables a reduction in chain size as you mention. I am deeply nervous of 316 stainless especially in high load situations having had too many stainless parts fail to be able to recall them all so it is a good idea to look for better.

I think the grade of stainless you are looking at is more commonly known as 2205 and is the cheapest duplex and depending on nickel prices is sometimes cheaper than 316. It should be a similar jump up in performance from 316 like going from 304 to 316. If you can get chain made in 4501 ideally or similar then you roughly double corrosion resistance again and importantly get a really big jump in stress corrosion resistance. It ought to be only a little more expensive.

I specified it in a rebuild of my davit gearbox recently and I expect it to last me out.

As to your towering chain problem, I have to knock the tower over several times otherwise I have a jam too. A handy access door helps. Stainless will fall much better.

[Duplexity]

I believe the chain I'm looking for is good enough to use in the Med..
But I'm not pretty sure and that's why I posted this thread.
The Duplex chain is made in Germany, tested and certified. I will have it electro polished and Ketten-Wälder offer 3 years warranty against corrosion, but only for Duplex not for 316L.
All Ketten Wälder's marine chains are in grade 60 or 60plus (I have seen a common standard of other manufactures are 316L in grade 50). K-W price list for Duplex (318LN) is 27% more expensive than 316L, but they also offer superduplex (A182F61) which is 130% more expensive than 316L. (Superduplex: €57 /meter).

[seandepagnier]

€57 a meter?

Wow, you could buy all the nylon you need for anchoring anywhere, or about 5 meters of this chain.

What exactly is the problem with line? I have seen so many cruisers using all chain, and they start using short scope habit because it "holds" until the wind really picks up like a serious storm, then it will drag for sure. I think they use all chain because everyone else does, not because it's better.

Same reason they use stainless steel for high stress areas like chainplates and standing rigging when there are cheaper better alternatives that have any issues.

If you use two anchors and only nylon line, the line will never cut because the two anchors keep from swinging around. This way you can save a lot of money, no rust, much easier to handle, and it's a lot safer because of proper scope, and redundant because always two anchors. Both anchors attach to bow.

[leftbrainstuff]

The duplex ss will likely be vacuum degassed. This means much less issues with impurities and related intergranular corrosion. The duplex will also likely have been post heat treated / normalised.

I'd personally struggle with the cost compared to good quality galv chain.

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