Strops, Knots and Lashings with Dyneema Single Braid ?

[akio.kanemoto]

Howdy,

I have just bought what looks like a mile of 1/4" Dyneema to make strops and other doodads out of and while I can make an eye splice etc - how does one deal with the following two situations:

1. Short strops (eye on each end): say only 1 ft (30cm) long. the tail/"bury" from each eye will end up overlapping in the middle of the strop. I was thinking of making perhaps one eye and using 2-3 times the strop length and making something like a lashing perhaps... BUT...

2. How do you end lashings with this stuff? It's quite stiff and slippery, and won't take knots. So if I make a lashing with it with an eye on one end and then pass the other end multiple times through the two things I'm lashing together then through the eye for tension... normally I would do a bunch of half hitches.. but what do you with this stiff/slippery stuff?

Thank you copiously in advance!

AK

[barnakiel]

I make regular Spectra loops (spectra/dyneema eye-splice and lock them with some handwork just behind the eye. Make the tails short so that they do not overlap in the central piece.

Lashings can be done the regular way ending up with half-hitches. You will probably make more than two though. Tight radius (e.g. round itself) works fine but damages the fibres. Large radius tends to get undone.

b.

[thinwater]

Would a sling (loop) work instead of 2 eyes? I don't know the application, but that is how short climbing slings are done.

Be wary of tensioning an eye back against the splice.

It would also help if you told us which product you are using; polyester jacket or no?

[Jim Cate]

AK, I think that the Colligo website has lashing instructions for their Dyneema stuff.

Cheers,

Jim

[barnakiel]

Beware of some instructions online. I have come across a couple where the eye was spliced by leading the tail twice across and then inside (plus whipping / sewing between the two crossing points). This gives a weak splice that may and will open if the whipping goes.

b.

[tropicalescape]

In my business(Paragliding)they always sew in loops...it has got to be done a certain way but I have never heard of a loop coming undone in flight...I dont think your supposed to wrap it around anything less than its own diameter or the fibers will break..dont know if this is on point but good luck..DVC

[akio.kanemoto]

Originally Posted by barnakiel

I make regular Spectra loops (spectra/dyneema eye-splice and lock them with some handwork just behind the eye. Make the tails short so that they do not overlap in the central piece.

Lashings can be done the regular way ending up with half-hitches. You will probably make more than two though. Tight radius (e.g. round itself) works fine but damages the fibres. Large radius tends to get undone.

b.

When you say "loop" in your above reply - I originally thought "end-to-end" splice to make a "circle", but the "eye" in your first paragraph confused me - maybe this is different to a big "circle"?

As for lashings - I've read that it is possible to make a "normal" lashing and use lots of half hitches, with a stopper knot at the end, but when I google "lashings" - I get a million different results which all look different. Do you have a link to one which you use/like?

Originally Posted by thinwater

Would a sling (loop) work instead of 2 eyes? I don't know the application, but that is how short climbing slings are done.

Be wary of tensioning an eye back against the splice.

It would also help if you told us which product you are using; polyester jacket or no?

Yes! I didn't think of that - a loop would work for one particular application, but I will require the lashings for other applications.

Product is uncovered. Like Amsteel.

The use cases I have are:

Strops: to attach tackles to stern cleats and other similar applications - basically flexible attachments.

Chainstopper: I have a 4 tonne rated folding padeye at the bow right next to the bow roller and want a short strop or loop attached to it, and a shackle/hook/claw on the other end to take the load off the windlass.

Originally Posted by Jim Cate

AK, I think that the Colligo website has lashing instructions for their Dyneema stuff.

Cheers,

Jim

Thanks for that, just found it - the link is here:

http://www.colligomarine.com/docs/mi...ie_ver_1_1.pdf

However, it only shows how to finish off a lashing, not to start one... maybe I'm showing my newbieness here but... does one start with an eye splice here?

Getting closer though!

[Jim Cate]

However, it only shows how to finish off a lashing, not to start one... maybe I'm showing my newbieness here but... does one start with an eye splice here?

Getting closer though![/QUOTE]

Yes, I think that one could use a small eye splice to attach the lashing to whatever is appropriate.

Jim

[akio.kanemoto]

Originally Posted by Jim Cate

However, it only shows how to finish off a lashing, not to start one... maybe I'm showing my newbieness here but... does one start with an eye splice here?

Getting closer though!

Yes, I think that one could use a small eye splice to attach the lashing to whatever is appropriate.

Jim[/QUOTE]

Great, will start playing with this then.

I ordered 150m of material directly from a factory in China - about USD220 for the roll and I have a genuine New England Ropes version here also and it compares pretty well actually. Initially I'll be using the NER stuff for the more critical applications and the Chinese stuff for less demanding ones, but I have a feeling that the Chinese stuff will be OK. It looks like they buy the fibres from the Netherlands (DSM?) and just do the braiding.

So have you packed yet? You should almost be ready to head to the airport!

[Jim Cate]

Originally Posted by akio.kanemoto

Yes, I think that one could use a small eye splice to attach the lashing to whatever is appropriate.

Jim

Great, will start playing with this then.

I ordered 150m of material directly from a factory in China - about USD220 for the roll and I have a genuine New England Ropes version here also and it compares pretty well actually. Initially I'll be using the NER stuff for the more critical applications and the Chinese stuff for less demanding ones, but I have a feeling that the Chinese stuff will be OK. It looks like they buy the fibres from the Netherlands (DSM?) and just do the braiding.

So have you packed yet? You should almost be ready to head to the airport! [/QUOTE]

Hey, that is a really good price, and I am interested to see some of it. The pukka stuff is kinda expensive!

And yes, we're packed and panting. Can't wait to get back to the boat.

Cheers,

Jim

[Weyalan]

Regarding short strops / long burys... I have been told that there is no problem with overlaping the bury of the tapered tail from the splice at one end of the stop with the tapered bury of of the tapered tail from the splice at the other end of the strop.

Dyneema is slippery. A 1/4" dyneema splice is probably going to need at least 250mm of bury (i.e. 40 x dimeter), and probably 300mm would be recommended (i.e. 48 x diameter) Assuming that you taper from half way doen the bury, it is probably only realistic to overlap the 2 tails to the start of the opposing taper. So, with 1/4 Dyneema you are unlile to be able to make a strop much shorter than 450mm + the eyes (and thimbles)... say 500mm overall.

[barnakiel]

Bad wording here, apologies. I meant a length of spectra with two eye-splices at the ends. I do not make spectra loops. If I did, I would probably make them by tying them with hunters bend. Endless spectra loops can be had, but I have no idea how they make them.

b.

[tropicalescape]

Originally Posted by barnakiel

Bad wording here, apologies. I meant a length of spectra with two eye-splices at the ends. I do not make spectra loops. If I did, I would probably make them by tying them with hunters bend. Endless spectra loops can be had, but I have no idea how they make them.

b.

are they not sewn..ever?.. i have loops on both ends of a cascade and the beginning of each cascade... hell of a lot easier than all that splicing... DVC

[barnakiel]

Originally Posted by tropicalescape

are they not sewn..ever?.. i have loops on both ends of a cascade and the beginning of each cascade... hell of a lot easier than all that splicing... DVC

Point is the eye splice on single braid new ropes is way easiest thing to do. Except if the line is very dense or stiff (this seems the case with dux used for standing rigging and torque ropes). But the plain stuff is most often very loosely woven and can be spliced by hand.

BTW I have looked up some sources and they say 5 dia is the minimum radius for loaded applications - where the rope may get loaded in the range of its WLL. Hence a loaded eye splice may require a thimble in some applications.

b.

[Weyalan]

I agree with the above poster's observation that a thimble is advisable in high load applications. Although specialised (fancy) thimbles are available, I have had no issues with using a conventional stainless steel thimble as used on conventional stainless steel wire rope.
N.B. Amateur self-taught (thanks Brion Toss) hacker here... so take all my advice with a generous pinch of scepticism and salt.