Galvanised D-Shackle

[vyv_cox]

Stainless/galvanised corrosion may not be a problem while the assembly is in the air, but is a recognised problem when immersed in seawater. You say yourself that it affects 2-3 links. Who wants that?

Maybe an extreme anchoring situation, but I regularly anchor for a period of one month, using two anchors in a Bahamian Moor, and made the mistake of using a stainless shackle at the join of the two rodes at 40m. On retrieval after only one month, the galvanising on a few links where the stainless shackle had been attached, was destroyed. Now that's a real nuisance, because it's not at the end of the chain, where it could easily be cut off, but in the middle of the rode.
Moral: stainless and galvanised should not be used together in seawater.

As I said earlier, not advised for moorings but perfectly acceptable for anchors. The chain adjacent to my Kong swivel was regalvanised by BE Wedge and is still pretty good after 7 years of anchoring nearly half the nights of the year. The three links of 10 mm chain between the Kong and the Wichard shackle are as bought, so considerably less zinc than the regalv length. I replaced them last year as they were looking rusty.

 

[NormanS]

As I said earlier, not advised for moorings but perfectly acceptable for anchors. The chain adjacent to my Kong swivel was regalvanised by BE Wedge and is still pretty good after 7 years of anchoring nearly half the nights of the year. The three links of 10 mm chain between the Kong and the Wichard shackle are as bought, so considerably less zinc than the regalv length. I replaced them last year as they were looking rusty.

Maybe it's something to do with the length of time that the materials are in the sea. As I say, my experience is related to an uninterrupted month under the water, which is admittedly unusual. I certainly don't want to include anything in the rode which will encourage rust on my chain, even for a few links.

 

[Ian_Rob]

I cannot answer your question directly but Jonathan Neeves may be able to. He is away at the moment and not participating in the forum but a PM should reach him in due course.

So far as your question is concerned I would concentrate on shackles made for lifting and hoisting. My tests of chandlery-bought galvanised shackles showed them to be pretty disappointing (see my website). However, stainless steel shackles from the same sources were far better and if you bought Wichard HT you would be buying one of the most reliable. Unfortunately I believe they have stopped making the type you want in this material. However, 3si sell high strength shackles (17/4PH I think) with socket head pins in their lifting and hoisting section https://www.s3i.co.uk/174socket.php.

What is your objection to stainless steel ones? Corrosion is not an issue with the combination of galvanised chain and anchor with stainless steel shackles on an anchor rode. After some years the galvanising may be corroded from the last couple of links but that's the worst it will get.

Sorry for my delay in responding.

I am not at anchor sufficiently often or for long enough periods for galvanic corrosion to be a problem so I may well opt for stainless steel. I just liked the idea of keeping everything galvanised and had assumed that it would be the simplest of tasks to buy a matching galvanised shackle.

Stainless Steel Direct who were suggested earlier in the thread can't provide any details on the breaking strain of their galvanised shackles.

Brierley Lifting Tackle Ltd sell a 12mm flush pin, galvanised shackle manufactured to DIN 82101 Type B with a certified WLL of 0.6 tons but that is only 540kg. As I understand it WLL (rather than MBL) is the equivalent of SWL load so it actually has a quarter of the stated performance of the Kong.

Makes me wonder the strength of the existing 12mm pin shackle?

Thanks for the link to S3i. They have high tensile s/steel, flush pin version with a 12.7mm pin with a SWL of 2 tonnes.

 

[GHA]

Maybe it's something to do with the length of time that the materials are in the sea. As I say, my experience is related to an uninterrupted month under the water, which is admittedly unusual.

Or possibly other factors?
I'm predominantly at anchor, this time permanently since September plus probably over a year before that with this chain West and East atlantic, chain looks perfect next to the stainless shackle.

 

[NormanS]

Or possibly other factors?
I'm predominantly at anchor, this time permanently since September plus probably over a year before that with this chain West and East atlantic, chain looks perfect next to the stainless shackle.

Yes, quite possibly, it may be that the mud in that location is particularly acidic. The land around it has lots of peat.
Generally, I'm very happy with the behaviour of stainless steel in a damp, salty environment, but I'm much less impressed with it permanently submerged.

 

[deep denial]

This is all very well - but how do you mouse a flush shackle? I wouldn't fancy trusting loctite alone.

 

[thinwater]

Yes, quite possibly, it may be that the mud in that location is particularly acidic. The land around it has lots of peat.
Generally, I'm very happy with the behaviour of stainless steel in a damp, salty environment, but I'm much less impressed with it permanently submerged.

Interestingly, we get that here in the spring. Lots of leaves fall in the creeks during the fall, and when the water warms in the spring, for about a month, anchors and chains can change color in just a few hours. Bacteria thrive and pH drops.

 

[Paddy Layback]

This is all very well - but how do you mouse a flush shackle? I wouldn't fancy trusting loctite alone.

Use the hard Loctite, number 648 from memory, on warm, degreased threads and do it up jolly tight (ie with a 1/2" drive Allen key, not one from the pound shop).
Furthermore, you could also bang a punch into it at the edge of the hex socket head, so it interferes with the hole in the shackle. No way could it accidentally unscrew itself, but you will have to grind it away to change anchors, whereas with 648 (check the number) you can just warm it up with a blow lamp to melt the Loctite.
Even furthermore, a dab of weld would do it (TIG with stainless filler rod is everywhere these days assuming you are talking about stainless shackles)


All these are more reliable than poxy Monel mousing wire, in my humble opinion..all mousing wire can wear away and catch on things, I've tried galv fencing wire, which goes rusty but you can renew it cheaply whenever, I've tried stainless MIG wire, which is very awkward to bend and work hardens, ie goes brittle, when you bend it, and and so does Monel.
They are all shyte in my opinion, if you want to sleep well at anchor.

 

[vyv_cox]

This is all very well - but how do you mouse a flush shackle? I wouldn't fancy trusting loctite alone.

I have been using Loctite 242 on my Wichard shackle and Kong connector for at least five years, anchoring most nights for about half the year. Before doing this I tested the torque of undoing the same fittings after immersion, initially for about a week but later after a whole season. There was absolutely no deterioration in the torque and every year it takes quite some effort to undo both the screws. https://coxengineering.sharepoint.com/Pages/Swivelconnect.aspx

 

[noelex]

This is all very well - but how do you mouse a flush shackle? I wouldn't fancy trusting loctite alone.

I drill a small hole in the head of the shackle and then cut it off almost flush.

The shackle pin can still be unscrewed (with vice grips). The shackle can be moused and the almost flush, smooth profile means that it does not catch on anything.

Modifying the shackle in this way enables the use of the wide range of hi test G8 shackles available with a conventional pin. Finding these sort of shackles with a flush pin can be very difficult.

 

[Ian_Rob]

It is mad that there isn't an off the peg solution to this.

 

[NormanS]

Some of us have sensible bow roller arrangements which are wide enough to accommodate ordinary shackles.

 

[noelex]

Some of us have sensible bow roller arrangements which are wide enough to accommodate ordinary shackles.

It would be great to see more yachts with sensible bow roller arrangments. I shake my head at some of the flimsy offerings of late.

However, even if the roller is wide enough (like mine) I still think removing the pin sticking out is worthwhile. If the pin catches on anything like the edge of the bow roller or even worse a hand or foot it can do some serious damage when pulled with a powerful electric winch.

In theory streamlining the shackle also helps with the anchor's setting and holding ability, although of course the effect will be slight.

I think the almost flush pin also discourages anchor theft. It looks like the shackle cannot be undone.

Anyway, it only takes a few minutes to modify the shackle. The only drawback is that pliers or vice grips are needed to undo the shackle, but these are usually needed even with a normal pin.