Soft Shackles - What is the Latest?

[transmitterdan]

Is any small thread and needle required to seize the burried tails as is required for a non-Brummell eye?

[model 10]

In the interest of being correct here on here on CF, we should be clear on the use of unravel when we mean ravel.

[estarzinger]

Originally Posted by transmitterdan

Is any small thread and needle required to seize the burried tails as is required for a non-Brummell eye?

pretty much anything will work.
For thread I use either: Heavy Tenara Thread, or waxed dental floss, or 80lb dyneema fishing line (in increasing size/strength).
For needles I just standard sail makers needles.

[Stumble]

Originally Posted by estarzinger

^^ BTW . . . regarding Thinwaters question about failures and the regular diamond knot . . . .The single most common failure I found when testing other people's soft shackles (and this includes several from Allen and from Brion) was that the knot is not tightened up firmly enough before the tail ends are clipped off short. What happens then is that when you exceed the 'pre-tension' level the tails will slip/suck into the diamond and it will unravel well before the expected breaking strength.

This is a tricky one because the knot will feel 'firm' and will look correct, but could have a lower than expected breaking strength. I used a hydraulic puller with a load cell attached and could make exactly repeatable full strength diamonds. Few people have that equipment, but if you winch them firm you can get close to repeatability by knowing how hard you lean on the winch handle - and if you were really detail oriented you could borrow a load cell for one round so you know numerically what you were doing.

The relevance of this to the 'stronger' shackle . . . .is that when you bury the tails you prevent them from slipping and getting sucked back into the knot and it unravelling. So you have in fact eliminated what I see as the most common failure mode/ construction error of the diamond. Of course in addition to increasing the ultimate strength.

I always try to preload them, but sometimes I just don't feel comfortable I have enough. Particularly when dealing with really small shackles (like 1.75mm) it can be tricky getting enough load. So instead I bury one leg inside the other and lock stitch the two together. I haven't tested them, but I also haven't had one slip either.

[Stumble]

Originally Posted by estarzinger

pretty much anything will work.
For thread I use either: Heavy Tenara Thread, or waxed dental floss, or 80lb dyneema fishing line (in increasing size/strength).
For needles I just standard sail makers needles.

When working with dyneema I have found that curved 'jumbo darning needles' or 'tapestry needles' work the best. They have rounded tips instead of sharp so they push the strands aside instead of pushing through, and they are long enough and strong enough to punch through easily. As an upside they are a fraction the price of stainless needles.

They are useless for sail repair since they don't have the strength to be hammed through things, but push well.

[estarzinger]

Originally Posted by Stumble

I always try to preload them, but sometimes I just don't feel comfortable I have enough. Particularly when dealing with really small shackles (like 1.75mm) it can be tricky getting enough load. So instead I bury one leg inside the other and lock stitch the two together. I haven't tested them, but I also haven't had one slip either.

My solution is just to cut the tails a bit long. I know roughly how much they can slip at breaking load, so I just account for that and cut them long enough that the tails ends can't be sucked all the way into the knot. It makes them a little less elegant than trimming the tails close but is "safer".

If you bury the legs, before (on the loaded side) of the diamond . . . . That will not prevent the tail ends from being sucked into the other side of the diamond as it tightens up.

[Stumble]

Originally Posted by estarzinger

My solution is just to cut the tails a bit long. I know roughly how much they can slip at breaking load, so I just account for that and cut them long enough that the tails ends can't be sucked all the way into the knot. It makes them a little less elegant than trimming the tails close but is "safer".

If you bury the legs, before (on the loaded side) of the diamond . . . . That will not prevent the tail ends from being sucked into the other side of the diamond as it tightens up.

I always leave the tails long until they have been fully loaded.

And I agree the bury alone won't help much, but I am hoping the lock stitch will help hold it until the knot clamps down.

[Seaworthy Lass]

Originally Posted by Seaworthy Lass

I am still a bit puzzled by the very final step of poking the poking ends down.
Allen shows them going through one hole as far as I can see (he spreads the overhand in the centre apart), although he does imply it is two holes.
You clearly say it is two:
"Look closely at the knot, and you will see two small triangular spaces in the very middle. To finish the knot you will tuck an end into each of these spaces."SWL

Originally Posted by estarzinger

^^

Take a look at this pic I have grabbed from Grog.

You can see the two holes I am talking about.

You have removed the separator by the way you are holding the standing parts apart.

I believe they end up the same, but Grog and my holding approach makes them a bit easier to dress - less likely the tails ending up sticking out the sides if you don't dress it all evenly

I have settling down for another go examining the Button for the "High Strength" soft shackle. Dissecting knots intrigues me .

This is the third evening I am attempting this and despite thinking I had it right yesterday, I have just tied one perfectly for the first time. Initially the dressing threw me (Evans, you are right, holding the standing ends well apart make it hugely harder to dress this knot properly, but I was only following Allen's photo instructions - he said nothing anywhere about regripping).

The final poke through was then a stumbling block. I knew I was missing something. The problem here was that once the working ends are poked through correctly they must be gripped in this position while dressing, or the weave will not be quite right. I had not been doing this.

It was your comment about selecting the pairs to bury at the end, that made me realise there can be distinctly different patterns for the configuration of the emerging lines after it has all been tightened. Only one occurs if the alignment of the poked through ends is correct (not what I had been doing).

Sounds confusing, but photos would help illustrate this and hopefully help anyone else attempting the Button for the first time. I will take some tomorrow.

SWL

[estarzinger]

^^ I just tied a button using grog's photo sequence and it went quite smoothly. They seem to be well taken, well sequenced instructional photos. I think they would be my first choice for the beginner atm.

In my own photo sequence I tried to show how it is made by tying two precursor knots (wall and crown knots). I personally found that to be easier to remember, as it breaks the button down into 3 simple steps (wall, crown and tuck ends). A bit like many people remember the diamond knot sequence as tying a carrick bend first and then tucking the tails.

the 'problem' with both the diamond and the button is that they are very much 3 dimensional constructions (to form spheres) and that is hard to capture in photos.

[Seaworthy Lass]

Originally Posted by estarzinger

^^ I just tied a button using grog's photo sequence and it went quite smoothly. They seem to be well taken, well sequenced instructional photos. I think they would be my first choice for the beginner atm.

In my own photo sequence I tried to show how it is made by tying two precursor knots (wall and crown knots). I personally found that to be easier to remember, as it breaks the button down into 3 simple steps (wall, crown and tuck ends). A bit like many people remember the diamond knot sequence as tying a carrick bend first and then tucking the tails.

the 'problem' with both the diamond and the button is that they are very much 3 dimensional constructions (to form spheres) and that is hard to capture in photos.

That is how I think of the Diamond - tie a Carrick first, dress it, then pass the ends around and through the centre. Makes it very simple.

I was not familiar with the Wall knot to start with, so that made it harder learning the Button.

By the way, for the bury once the Button is tied for a soft shackle, do you cut the two working ends different lengths to stagger them under load, plus taper them as well? I imagine the length of bury does not have to be much as strengthening just the bit near the base of the stopper is the aim?

SWL

[estarzinger]

Originally Posted by Seaworthy Lass

By the way, for the bury once the Button is tied for a soft shackle, do you cut the two working ends different lengths to stagger them under load, plus taper them as well? I imagine the length of bury does not have to be much as strengthening just the bit near the base of the stopper is the aim?

I did quite a bit of testing on the bury.

Taper does not hurt, but also not really necessary as it is not the weak point even untappered (the noose is). I taper a bit to make it look nice and smooth, but only about 1/3 as long as a proper bury splice taper.

The bury does need to be long enough to have some grip, so it is "integral" to the pieces it is inside, otherwise it actually does not strengthen it anywhere as much. I probably wrote on my website what the minimum bury was from the testing, but I think I remember like 28 diameters.

I never thought about staggering the tail lengths. That would make it all "smoother" but I don't think it would effect the strength much . . . Because again, once you do the bury this is no longer the weak point in the shackle. The weak point is now the noose.

[Seaworthy Lass]

Evans, thanks for the info.

Originally Posted by Seaworthy Lass

For anyone interested in using soft shackles to connect the snubber to the chain, before we drop anchor I will try and snap a shot of our old one currently in use and will also later post some feedback on our experience with them.

Feedback on the use of soft shackles to connect snubber to chain:

This is the type of original design "Classic style" (= "ColligoMarine style") soft shackle we have been using for the last 18 months. This particular one has been in use for about the last 6 months:






This is how it looked when it was new:



Line used: 6mm Amsteel Blue
Chain: 10mm G7
Boat: 48' aluminium cutter rigged sloop

Our snubber itself breaks occasionally (we anchor out all year in the Med and conditions can sometimes be wild), but a soft shackle has never failed.

SWL

[jcapo]

Originally Posted by estarzinger

My solution is just to cut the tails a bit long. I know roughly how much they can slip at breaking load, so I just account for that and cut them long enough that the tails ends can't be sucked all the way into the knot. It makes them a little less elegant than trimming the tails close but is "safer".

Evans, do you have an idea how much tail would pull into a diamond knot after it was tightened with somewhere north of 1000lbs straight line pull from eye to tails. I think that would be the same as ~2000lb load on the knot when in the normal closed configuration as a shackle. This is 3/16 AmSteel.

I say north of 1000lbs because I was able to break a piece of 7/64 AmSteel 18" away from the long taper 72 diameter bury eye splices on each end. I pulled it with a Lewmar 52 cockpit winch and it was "difficult" to break it. That should have been 1400lbs or so. So I think I can reliably pull to at least 1000lbs.

I can't suck the tails in at all on a 3/16 diamond knot shackle after tightening the knot as above and pulling on it in closed shackle configuration with the Lewmar 52.

A 1/4" tail is fine on my boat with the load I am putting on a 3/16 shackle. I am starting to make shackles for other people and I'm trying to decide how much tail to leave for safety but short enough to not get in the way.

Comments appreciated.

[boatsail]

I use these things for everything. Here are a couple of good videos. I learned to make them using the Colligo video

https://www.youtube.com/watch?v=6RwxBSMBfzs

https://www.youtube.com/watch?v=6RwxBSMBfzs

WM sells a kit that has all of this included in a plastic containter with "rubber lid". I'm sure there are better, but the one I got worked for me. Samson Fid Kit

[Seaworthy Lass]

Originally Posted by transmitterdan

I am most interested in the "high strength soft shackle". It seems it should be easier to make and Evans tested it as stronger than the others. The button knot has lots of examples on the web but the rest of L-36 instructions are difficult to understand, several grammar errors and there are no in-process photos. If you can post a series of photos how to make this shackle that would be great I think.

I have posted instructions for the High Strength soft shackle here:

http://www.cruisersforum.com/forums/...ot-155591.html

Posts 4-20 are specifically for the Button. I think this clears up the uncertainty of where to poke the working ends down through the knot in the final step. I found this very difficult to work out from the instructions I found currently available.

Posts 21-33 are for the whole shackle.


Instructions for the new BB shackle (a hybrid between the High Strength and Better) can be found below. I guess that answers the question I posed in my first post in this thread.
This is the latest :

http://www.cruisersforum.com/forums/...ml#post1954306

SWL

Edited to add:
This is how the BB soft shackle looks: