12mm Anchor Chain - corrosion too much

[SailingHarmonie]

Originally Posted by Papawads

Thanks the many kinds words, some contradictory, but all well-meaning. We're erring on the side of caution and replacing the chain, as some sections had lost 1/8th of their 10mm thickness.

The cause? It's our first boat. We didn't even realise the far end of the chain was sitting in 1-2 inches of water permanently until the first time we used all 100M (300ft) of chain.

We raised the locker floor with plastic grid matt, but it still meant a very damp locker with much water in the base.

So before the new chain goes in, I'm raising the whole base to drain/dry fully and reducing from 100M to 75M with another 50M of nylon rode stored elsewhere for the 2-3 times a year we might need it. The reduced length is to keep a good drop.

Will install a corse plastic gauze too, to act as a preventor for drain clogging.

Finally, as I've see others do, will put the chian on a pallet on the ground when the boat is on the hard.

Any other suggestions welcome. If I need to replace this chain again in the next 5 years, the Admiral will poisen my Subday dinner.

Thanks
Papawads

Good start with the changes you are making. At least once a year, swap the chain end for end to even out wear and corrosion. A fresh water rinse can’t hurt, but most small boat chain lockers ship enough salt water that makes little difference in the real world.

Finally, buy chain that has been hot-dipped galvanized. Ask! You’ll pay more but it is worth it. Cheap electrogalvanizing will begin to fail to 2 or three years.

[rognvald]

Originally Posted by SailingHarmonie

This is way, way past rescuing by regalvanizing. There is significant metal loss. This is what happens when routine maintenance is ignored.

Yes!!
Rognvald

[donradcliffe]

The galvanizers don't like to deal with that much rust. Take it out on the beach and drag it through the sand for a mile before you bring it to them.

[dlj]

My anchor locker has a drain. Any water coming in drains out.

dj

[sy_gilana]

Just a few points.


It is dangerous to swap ends on your chain. The unused rusty bit in the locker will clump up, and is very likely to jam in the Spurling hole or pipe on release. This is a dire situation prohibiting weighing or jettisoning. The worn galvanizing on the working part will rust slower in the sea.

Put an anode on your anchor stock near the shackle.
Never use a stainless shackle or swivel on a Galv chain.
All superyachts and ships flake the chain according to class survey requirements.
Superyachts have wood lined chain bins to keep noise down.
I always leave a few old anodes on the bottom of my locker.

Using High Tensile Chain is counter-intuitive, what you want is weight, if not, we would all be using Dyneema.
Galvanizing does not damage low test (Heavy) chain which should be oversized anyway.
Our chain has been galvanized 3 times, basically every 8-10 years.

[dlj]

Originally Posted by sy_gilana

Using High Tensile Chain is counter-intuitive, what you want is weight, if not, we would all be using Dyneema.
Galvanizing does not damage low test (Heavy) chain which should be oversized anyway.
Our chain has been galvanized 3 times, basically every 8-10 years.

The idea that what you want is weight has been pretty well debunked.

Dyneema is not used because of chafe issues.

dj

[dave777]

Originally Posted by dlj

The idea that what you want is weight has been pretty well debunked.

spadeanchorusa does a good job explaining Catenary as to the benefit of chain immediately before the anchor.


Weight is the key, though of course chain has advantages vs chaffe

[dlj]

Originally Posted by dave777

spadeanchorusa does a good job explaining Catenary as to the benefit of chain immediately before the anchor.


Weight is the key, though of course chain has advantages vs chaffe

Perhaps my statement was a bit too short. The difference in running all chain rode from a low strength heavier chain to a high strength lighter rode makes no notable difference in catenary effects - of course within reasonable size limits.

Reasonable size limits meaning the same boat that would use X size low strength chain switching to the same boat using lighter high strength chain would not notice any difference in the performance of their anchoring system.

dj

[motion]

I would suggest 200ft of new chain. On a refit I replaced several items but did not think of the anchor chain. In a minor hurricane, 100 kts, the chain broke and I ended up on the beach. By all means get a new chain

[sy_gilana]

Originally Posted by dlj

The idea that what you want is weight has been pretty well debunked.

Dyneema is not used because of chafe issues.

dj

Fact: you cannot debunk a fact. Its funny that way. No matter how many sums you do, I know that my heavy chain outperforms the boats that have dragged past me every year for the last 26 years, full time, live aboard, at anchor more than 9000 nights, in 2022, 6 boats dragged past me, in one squall, all with Rocna anchors, using skinny high test chain. I am the guy in the dinghy racing over in the storm to help. I would not change my BBB 1/2" to a smaller High test.


I don't care what you think, just don't anchor in front of me please.


This is why I hardly ever come to the forum anymore. I try to give helpful info but there's always this .....

[Icarus]

Originally Posted by Papawads

Hopefully, once I post this there is an accompanying photo, otherwise the next question is pointless...

Do you think this section of 12mm chain is dangerously corroded, or do I still have time?

Not sure how the Admiral will take a request for a 100M of new! The thought alone makes be go pale.


Papawads

Try to clean it up and inspect for pitting and loss of material across the links...I say most likely replace it..I would
12mm chain is quite a HD chain..how big is your vessel?

Still cheaper to replace the chain than winding up on the beach or worse.

[dlj]

Originally Posted by sy_gilana

Fact: you cannot debunk a fact. Its funny that way. No matter how many sums you do, I know that my heavy chain outperforms the boats that have dragged past me every year for the last 26 years, full time, live aboard, at anchor more than 9000 nights, in 2022, 6 boats dragged past me, in one squall, all with Rocna anchors, using skinny high test chain. I am the guy in the dinghy racing over in the storm to help. I would not change my BBB 1/2" to a smaller High test.


I don't care what you think, just don't anchor in front of me please.


This is why I hardly ever come to the forum anymore. I try to give helpful info but there's always this .....

Apparently I've offended you. Apologies, that was not my intention.

As to your statement "it's all about the weight" - perhaps you can teach me. So explain to me how the chain weight gives advantage when the wind speeds are such that your chain is being pulled straight. No catenary left - just a straight line from your attachment point on the bow to the attachment point on your anchor?

dj

[Icarus]

Originally Posted by fxykty

Take it for regalvinising - they will sand blast or ceramic bead spin it to clean steel, then hot dip in a zinc bath, then tumble it to get a nice as new chain.

If you’ve got a higher grade chain let them know and they should use a lower temperature bath. If they don’t know about that, use a different regalviniser.

Galvanising temp is 443°C according to AS/NZS 4680..Standard.
No galvanising plant is 'lowering' the temp of the molten Zinc pool...

[Icarus]

Originally Posted by Papawads

Thanks the many kinds words, some contradictory, but all well-meaning. We're erring on the side of caution and replacing the chain, as some sections had lost 1/8th of their 10mm thickness.

The cause? It's our first boat. We didn't even realise the far end of the chain was sitting in 1-2 inches of water permanently until the first time we used all 100M (300ft) of chain.

We raised the locker floor with plastic grid matt, but it still meant a very damp locker with much water in the base.

So before the new chain goes in, I'm raising the whole base to drain/dry fully and reducing from 100M to 75M with another 50M of nylon rode stored elsewhere for the 2-3 times a year we might need it. The reduced length is to keep a good drop.

Will install a corse plastic gauze too, to act as a preventor for drain clogging.

Finally, as I've see others do, will put the chian on a pallet on the ground when the boat is on the hard.

Any other suggestions welcome. If I need to replace this chain again in the next 5 years, the Admiral will poisen my Subday dinner.

Thanks
Papawads

You doing fine..