G70 chain

[GHA]

Fair enough. My image of wandering seabirds, touching land only once every few months, was obviously not quite right.

Not met those ones. But then again you wouldn't would you

On fifth anchorage in 3 days now now, didn't quite like where it was next to the channel so moved a bit and put 2 hooks down bahamian style - 10m of g70 6mm would be nice for that, bit of a faff with 10mm chain in the dinghy even if it was only about 6m then rope. Sweaty now!

 

[JumbleDuck]

Not met those ones. But then again you wouldn't would you

All those Dutch lessons, wasted. Though I now have beautifully clear sinuses.

 

[NormanS]

Because Dyneema floats and wraps itself round your keel, rudder and prop - and is rather difficult and expensive to cut free. It would also be a nightmare to detach if caught in coral.

In light winds if you have light chain the catenary (and friction on the seabed), that is always there (even at the mythical 70 knots), is less effective than with big chain. Once the winds increase, with lighter chain, you replace that portion of the catenary you have sacrificed with elasticity (snubber).

I can assure you, from genuine experience, that there's nothing "mythical" about 70 knot winds.
I'm now sitting here at home, having left my boat anchored (Bahamian Moor) in a "sheltered" sealoch in the Outer Hebrides. Needless to say, there are now gales forecast!

 

[cindersailor]

I confess to have reiterated this base(less) information, as have others.

However I had a search and there is no data base anywhere that I could find to support the contention (that a second galvanising damaged the specification of gal G70). I decided to investigate. The concept has no technical foundation, regalvanising G70 is technically feasible, there is no loss of strength the concept (re-gal) of G70 has the technical support of one of America's biggest chain makers. The data will be available in the next few weeks.

Jonathan

My understanding is that it is not the actual regalvanising that is of concern in weakening high tensile steel chain, but the acid pickling that is used to remove the remaining zinc before the new galvanising is put on. The pickling produces hydrogen which is thought to be responsible for 'hydrogen embrittlement' of the steel. Take a look at https://www.nace.org/Corrosion-Central/Corrosion-101/Hydrogen-Embrittlement/ which indicates that "The most vulnerable are high-strength steels"

 

[vyv_cox]

My understanding is that it is not the actual regalvanising that is of concern in weakening high tensile steel chain, but the acid pickling that is used to remove the remaining zinc before the new galvanising is put on. The pickling produces hydrogen which is thought to be responsible for 'hydrogen embrittlement' of the steel. Take a look at https://www.nace.org/Corrosion-Central/Corrosion-101/Hydrogen-Embrittlement/ which indicates that "The most vulnerable are high-strength steels"

But a G70 chain steel is by no means high strength. High strength steels will typically have at least 0.4% carbon plus nickel, chromium, vanadium and maybe other alloying elements. It would be quite difficult to cut them with a hacksaw. This is a far superior analysis than chain steel.

 

[Neeves]

My understanding is that it is not the actual regalvanising that is of concern in weakening high tensile steel chain, but the acid pickling that is used to remove the remaining zinc before the new galvanising is put on. The pickling produces hydrogen which is thought to be responsible for 'hydrogen embrittlement' of the steel. Take a look at https://www.nace.org/Corrosion-Central/Corrosion-101/Hydrogen-Embrittlement/ which indicates that "The most vulnerable are high-strength steels"

HE is acknowledged as a potential issue and more importunely acknowledged as a deterrent to use of high tensile galvanised products. So whether the specific HT steel might be susceptible or not, taking note of Vyv's comments - its incorporated into process,

There have been some spectacular failures, HT bolts that were pickled. You will find, for example, that the bolts holding up wind farm towers are not pickled prior to galvanising

Which is why HT steels, including G80 and G100, are sand blasted not acid washed.

You will also find that if your chain is painted and you want to regal - it might need sand blasted. You need to abrade and galvanise almost immediately, a couple of hours. So having a galvaniser and sand blaster adjacent, or the same site, is advantageous.

 

[thinwater]

What percentage of people ever re-galvinize a chain? I know that in my part of the US, folks discuss it, but the existence of shops that will do it for a price worthy of the remaining value of the chain or anchor is mythical.

My feeling is that the point is mute most places.

 

[Neeves]

What percentage of people ever re-galvinize a chain? I know that in my part of the US, folks discuss it, but the existence of shops that will do it for a price worthy of the remaining value of the chain or anchor is mythical.

My feeling is that the point is mute most places.

I agree, from an Australian perspective -

but also think - its such a critical item, why skimp? People don't think twice about buying AIS at $xxx, or a new phone for even more - but want to save when new chain costs much the same.

Would not do if we were not all so different.

 

[thinwater]

I agree, from an Australian perspective -

but also think - its such a critical item, why skimp? People don't think twice about buying AIS at $xxx, or a new phone for even more - but want to save when new chain costs much the same.

Would not do if we were not all so different.

And I am an advanced cheapskate!

https://www.amazon.com/Keeping-Cruising-Boat-Peanuts-Drew-ebook/dp/B071ZP1CTW?_encoding=UTF8&psc=1

 

[Neeves]

And I am an advanced cheapskate!
View attachment 64841
https://www.amazon.com/Keeping-Cruising-Boat-Peanuts-Drew-ebook/dp/B071ZP1CTW?_encoding=UTF8&psc=1

if there is be fight about degrees of parsimony - there could be a rash of contributors

 

[NormanS]

What percentage of people ever re-galvinize a chain? I know that in my part of the US, folks discuss it, but the existence of shops that will do it for a price worthy of the remaining value of the chain or anchor is mythical.

My feeling is that the point is mute most places.

"Mute"? Two Nations divided by a common language.

I, and several others that I know, have had our anchor chains successfully re-galvanised without any problems. I imagine that they are all mild steel chain.

 

[vyv_cox]

"Mute"? Two Nations divided by a common language.

I, and several others that I know, have had our anchor chains successfully re-galvanised without any problems. I imagine that they are all mild steel chain.

Both my anchor chains (two boats) have been regalvanised successfully. There is a page on it on my website.

 

[thinwater]

"Mute"? Two Nations divided by a common language.

I, and several others that I know, have had our anchor chains successfully re-galvanised without any problems. I imagine that they are all mild steel chain.

Should have type "moot." To some, debatable, to others, not important.

I would not hesitate to re-galv, but there is no practical availability and the cost would have to be no more than 1/3 new, which it is not (more like 70-120%). So I will never have the opportunity to re-gal an anchor or chain, and thus don't care. If it is practical for you, then it's a valid approach. But from what I'm hearing in the US, the answer is ~ 85% "no." Yup, we live in an increasingly disposable society.

 

[vyv_cox]

Should have type "moot." To some, debatable, to others, not important.

I would not hesitate to re-galv, but there is no practical availability and the cost would have to be no more than 1/3 new, which it is not (more like 70-120%). So I will never have the opportunity to re-gal an anchor or chain, and thus don't care. If it is practical for you, then it's a valid approach. But from what I'm hearing in the US, the answer is ~ 85% "no." Yup, we live in an increasingly disposable society.

The major advantage in regalvanising is that the zinc thickness might be 4-5 times greater than the shaken and centrifuged production stuff. These photos illustrate.

The original chain that I had regalvanised lasted three years. Despite end-for-ending it the rust was running down the decks. The regalvanised version has been in place for 7-8 years now and despite considerable use it will give me a couple more seasons at least.

 

[Neeves]

Interestingly everyone, here, who has regal says the same thing - the regalvanised coating is better than the original and some of you have the process done by companies that used to make and sell anchor chain.

you would think chain makers would get it right the first time, though prioritising longevity is maybe a bad business model.

New Chinese chain here costs 2 times, about, the cost of regal - ignoring transport and any extra to remove paint. Regalvanising of chain is done here but it is not common. One impediment - we do not have a facility like YBW to allow a number to get together and keep costs down.

 

[Kukri]

The major advantage in regalvanising is that the zinc thickness might be 4-5 times greater than the shaken and centrifuged production stuff. These photos illustrate.

The original chain that I had regalvanised lasted three years. Despite end-for-ending it the rust was running down the decks. The regalvanised version has been in place for 7-8 years now and despite considerable use it will give me a couple more seasons at least.

Also my experience.

 

[Yngmar]

Perhaps a bit late to the thread, but we've recently replaced our rusty old 8mm chain with a 75m length of Maggi Aqua 7 (Grade 70) 8mm chain. Paid 839 EUR including shipping to the UK. Only problem was we then got sucked into some strange Italian disturbance in the space-time continuum and ended up waiting nearly 2 months for delivery.

Other than that delay we're quite happy with it so far. Although despite a very sloped floor in the anchor locker, the pile needs a shove with the windlass lever to be knocked over if we had more than 40m out, else it'll pile up and jam upon retrieval. Oh, and all the green stuff that came up anchoring in Cherbourg made me want to fit a washdown pump.

You can see the rest of the setup illustrated below:

 

[vyv_cox]

Does the swivel articulate OK with that shackle? When I first tried that the whole lot would jam down the anchor shank, which was why I developed the three links of chain method. Photos on the website.

 

[Yngmar]

Does the swivel articulate OK with that shackle? When I first tried that the whole lot would jam down the anchor shank, which was why I developed the three links of chain method. Photos on the website.

Yes, I'm aware of your solution and checked for this problem, but it doesn't seem to occur for me. Probably the size of the shackle plays a role here. Mine's 12mm - a 14mm would've fit too (the anchor slot is 15mm wide and the swivel 22mm), any smaller and it probably would jam. Also it's important that it is a bow shackle rather than a D one. Kong recommends this setup in their instructions for non-articulated (CQR type) anchors and so far it seems to work (we've been anchoring in tidal waters and swinging around the hook merrily).

 

[Neeves]

Yngmar,

Thanks for filling in your usage. Couple of queries, why did you buy G7 in the first place and what did you have previously. I've looked at a number of samples of Maggi's A7, your chain will be marked as such, and the link size is very small, I could not use a 3/8th" shackle, the clevis was just too big. Your use of the swivel to attach to the chain implies an even small clevis -is it an oval shape to give the strength they specify?

edit another query - what sort of snubbers are you using? close edit

Jonathan