Monel seizing wire for mooring shackles

jonathankent

jonathankent

Well-Known Member
Joined
23 Dec 2005
Messages
1,733
Location
Cornwall
Visit site
Forgive me if this is rather a rookie question, but.... do I just 'wrap' this wire through the eye and then through the shackle a few times and 'job done', or is there more to it?? It is bloody stiff, so I would think this would keep the pin secure enough.
 
I wrap it through in a figure of eight. Slightly straighter pull on the wire when it's under stress - ie trying to undo. It works for me but I don't claim to be right.
 
FYI when I set my mooring up last month I was advised not to use monel wire for this as it would set up dissimilar metal corrosion - galvanized wire was recommended, which I got from a garden center for not very much.

Andy
 
I've twice had my boat come off the mooring due to a shackle done up the way you describe (ie. b... stiff and fig 8 monel wired) coming undone. By incredible good fortune, once I was on board and the other time on my way out to the mooring in the water taxi, so both times managed to restore situation.

This led to me asking guys who set up moorings how to prevent it happening again - hopefully these two extra bits of info will help prevent yourself & others suffering my (rather scary) experiences.

1. Once done up tight, use a ballpein hammer to hit the treaded end of the shackle bolt over on the outside of the shackle (rather like old fashioned riveting). Mark Trout, (of Trout's boatyard, rents out moorings on the upper Exe) told me he's even had shackles come undone despite this.

2. This one's easier to explain face to face, but here goes: the shackle needs to be the correct way round - one way, each time a swell lifts the boat & pulls on the chain it puts torsion on the shackle bolt which tends to undo it, the other way round it tends to tighten it. (try it with some spare chain & you'll see what I mean) When each wave has passed the lesser tension means this effect doesn't work the other way round.

Might be 'belt & braces', but I'd have a couple less scars on the old myocardium if I'd known this before....
 
I had some old galvanised fencing wire in the back of the shed. Unstranded (is that a proper word?) it and used that so no dissimilar metals. It's also more workable than monel. Don't nick it from a farm hedge though, cos you might end up with sheep everywhere!
 
trust me DO NOT use monel or stainless wire.
if you do watch it eat the end of the shackel in a year.
heavy duty tie wraps are the only answer.
 
This is how I do mine

mastblock.jpg
 
[ QUOTE ]
trust me DO NOT use monel or stainless wire.
if you do watch it eat the end of the shackel in a year.
heavy duty tie wraps are the only answer.

[/ QUOTE ]

Never had a problem personally, to advise the use of weak tie wraps for this job is in my opinion bad advice and should not be followed. If a shackle is important enough to be seized, then do it properly, not with a tie wrap.
 
I laid my own moorings for many years in the tidal thames near Tilbury. Never had any problems with monel wire causing corrosion or with shackle pins coming undone. I just used to wrap the wire tightly around the shackle body and pin hole using pliers to pull each turn tight and finishing by twisting the ends and tucking them out of harms way. Careful not to twist the ends too tight or the wire will be strained and weakened. I suspect galvanising on shackles may be thinner than it used to be. I fiound that a coating of hard lanolin protected the shackle pin thread so it was easy to unscrew even after being immersed for a year or two.
 
My advice is not to use wire-ties ( too vulnerable) and not to use monel metal as I have seen dissimilar metal problems caused by this. Most of the people who lay moorings professionally round here use monofilament electric cable taken out of household twin-and-earth with the insulation left on. Although the wire is copper, the insulation prevents electolosis. I.5mm twin-and-earth is the best size to use.
 
The right way round thing is fairley easy to work out. Hold the shackle in your right hand with the jaws away from you and the threaded jaw to the right. Hold the pin in your left hand. If the riser chain is lifted and suspended from your foredeck (that is is still top at the top, bottom at the bottom) put the jaws of the shackle around the chain and pass the pin through from the left and tighten. You'll see that as you pull up on the shackle it will tend to wind the pin further in.

I wouldn't use copper based wire. It's too soft. Wind your seizing wire around the leg of the shackle near to the pin eye (like the cable tie in the pic) so it's less likely to get attacked by errant chain links.

A combination of cable ties, seizing wire and peening the threads seems pretty good.

You can't quite see in the pic but the smaller shackles have wire as well.
This shot was taken before the peening.

Newchainriser.jpg
 
Now I am more confused than when I started.... it seems a very divided subject as to what method is best, some say use monel wire and some don't. I remember reading a thread a couple of weeks ago about moorings and the use of cable ties also.

So what if I was to use the monel seizing wire and to try and protect against this wearing through put a cable tie in also?? I can't see many ways of securing the shackles, yet there are 1000s of boats out there safely moored....
 
[ QUOTE ]


So what if I was to use the monel seizing wire and to try and protect against this wearing through put a cable tie in also??

[/ QUOTE ]So you didn't read my post?

[ QUOTE ]
A combination of cable ties, seizing wire and peening the threads seems pretty good.

[/ QUOTE ]
 
You must log in or register to reply here.

Share this page

Top