Underwater thread sealer for shackle

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afterpegassus

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When I last dived to check my mooring, I discovered the monel mousing on the 8 1/2 ton shackle, between my ground chain and riser, worn through (I believe by action of the riser's hard eye against the shackle).

I installed a three part shackle with a split pin as a temporary fix, but my intended solution is to instal a new three part shackle with the nut and pin drilled so that I will be able to mouse but without the mousing intruding into the bow of the shackle where it might be worn through again.

I would also like to use a thread sealant (belt and braces) and my question is, which sealer, that can be applied underwater, would be the best to use in these circumstances?
 
I don't think there is one you can apply underwater. There are several that you can place underwater but they all need to be applied to clean dry equipment..

You could use a lifting shackle with a split pin through the end.... That's not going to come undone, I use them regularly for underwater lifting operations.

Like this one for example.... http://www.ebay.co.uk/itm/3-25-tons...006615?hash=item19c416bbd7:g:fFcAAOSwfcVUFzbp
 
You could try clearfix an everbuild product available from toolstation,claims able to be used underwater.Do a test run first .I always fit a close fitting SS washer behind the SS split pin on the safety shackles.
Jim
 
I have used spacer rings on the shackle pin so that the chain link is kept central, and therefore clear of the mousing wire.
 
Some people use an epoxy, mix the 2 parts above water and apply underwater. Not sure what the brand or part number is, but I've seen divers using it.
 
afterpegassus said:
When I last dived to check my mooring, I discovered the monel mousing on the 8 1/2 ton shackle, between my ground chain and riser, worn through (I believe by action of the riser's hard eye against the shackle).

I installed a three part shackle with a split pin as a temporary fix, but my intended solution is to instal a new three part shackle with the nut and pin drilled so that I will be able to mouse but without the mousing intruding into the bow of the shackle where it might be worn through again.

I would also like to use a thread sealant (belt and braces) and my question is, which sealer, that can be applied underwater, would be the best to use in these circumstances?
Click to expand...

I gave a response to this (#5), but now I'm not sure, as I don't know what you mean by a "three part shackle". Please enlighten me.
 
It is terminology in use where I work.
A "two part shackle" is a conventional shackle of two parts - body and pin.
A "three part shackle" is body, hex head pin and nut (though properly, four parts with the split pin) sometimes called a safety shackle.

I use them all the time simply because I have ready access to them owing to rigging lofts being skipped every six months.
Spacers is a good idea and will probably include this when I replace the shackle.
In response to G12, this is what I have as a temporary measure, but a nut and split pin are not a long term solution.
 
Does the pin in your 3 part shackle thread into the body or rotate freely?
I have had good results with an ordinary shackle, pin replaced with bolt, locknut added, with a spring washer under the locknut.
For additional security, drill through the locknut and lockwire it.
I believe in torquing these things with decent spanners, not finger tight or a little shackle key....
 
lw395 said:
Does the pin in your 3 part shackle thread into the body or rotate freely?
I have had good results with an ordinary shackle, pin replaced with bolt, locknut added, with a spring washer under the locknut.
For additional security, drill through the locknut and lockwire it.
I believe in torquing these things with decent spanners, not finger tight or a little shackle key....
Click to expand...

I have done something similar, but without the spring washer, and drill the bolt beyond the nut. Rather than Loctite or similar on the threads, I put Coppaslip on them. These ones are only for six months use, and get renewed every year.
 
"Does the pin in your 3 part shackle thread into the body or rotate freely"
The shackle was described in#8. Yes the pin can rotate

"drill through the locknut and lockwire it."
This is just what I proposed in par2 of my original post.
This is the first time I have seen the mousing part in the way it has, having had the same mooring set-up for 14 years. It has led me to thinking of alternative methods of securing the shackle pin. I inspect things myself every year and usually get at least 4 years before a change of shackle is warranted.
I will "nip" my shackles, but no more as those I use (Crosby) are not intended to be forcefully tightened.
 
We seem to hear of a few mooring failures attributable to reliance on mousing or lockwiring.
I would only use lockwiring as a second/third line of defence for a shackle that is done up tight with an additional locknut.
Loose pin shackles can fret away at mousing and lockwiring over time.

I think this thread is about shackles well below buoy level, but in the solent, you should never rely on mousing or wiring a shackle within a metre of the surface as some cretin will come along and lasso your buoy, ripping off the mousing wire.
The pro's around here tend to weld shackles.
 
Boo2 said:
This presumeably done on the hard while making the entire assembly before dropping it in the harbour ? Or do they carry welding bottles out to the mooring ?

Boo2
Click to expand...

It's not really such a big deal. Think of the little welding plants which work from a 13 amp socket. One of these and a quite modest generator, and you're good to go. I just mouse mine.
 
I use lancote on underwater shackles - thick gunge of pure lanolin. Smells like a New Zealand sheep farm ( appologies to New Zealanders, farmers and sheep )
 
Boo2 said:
This presumeably done on the hard while making the entire assembly before dropping it in the harbour ? Or do they carry welding bottles out to the mooring ?

Boo2
Click to expand...
It's done on the barge with a welder-generator mostly.
 
vyv_cox said:
I have tested Loctite 242, assembled above the water but then immersed for long periods on my anchor swivel and shackle. I found no reduction in the loosening torque at the end of the season.
Click to expand...

I did almost the same as Vyv. I also tested but applied the Loctite to the pin in the dry (its easier that way) I then assembled under water. edit I was fairly generous with the Loctite as I was not sure if applying under water would allow any to wash off - I do not think I need have worried, close edit. I simultaneously, well a few minutes later, did the whole thing dry. I left both to set off for 48 hours and using a torque gauge could not tell any difference. I used 6 identical shackles for each test. I think there are a number of Loctite formulations that will achieve this result, make sure they are anerobic. As you are looking for longevity the 'type' that needs heat to release might be best, though you will need a blow torch.

If you are twitchy - simply try it. The experiment is not complicated.

Jonathan
 
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Thanks for all the input.
Welding shackles for moorings I certainly approve of but I neither have the expertise or tooling to do this underwater.
I will drill the nut and pin, apply Loctite topsides and assemble underwater, finally mousing through the drilled hole.
If I remember, I will feedback on the next inspection.
 
Our mooring is lifted, 1t block, once a year. The shackle is welded, if it needs replaced its cut off.

I used a Loctite that needs heat to release. I was a bit generous and could not move a shackle pin even with a big shifter - I did need the blow torch (as the instructions had said). It would not be any easier underwater :( but might be possible with 2 big shifters - its good stuff. Just use a 'normal' anerobic Loctite, Vyv mentioned the number earlier (242?).

Jonathan
 
We use various Loctite's subsea all the time. As long as they can go off before immersion there's no problem. Can't remember the specific type now but there's one recommended by Schilling Robotics for use in their T4 manipulator arm. It's green.... I'll go outside and look later.
 
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