1/4" dyneema lifeline questions

[rdykiel]

Hi I'm hoping to replace my lifelines with 1/4" dyneema. Never done that and trying to learn how to make eye splices. I have 2 questions:

- is the splicing wand you are selling online a good tool for this, and if yes, what size?

- is it ok to use lashings to tie the line at the bow pulpit, and if yes, is tarred seine acceptable there (what size), or some other material?

Thanks

[Brion Toss]

Hello,
First, I can objectively state that the Wand is an excellent tool for this job. As for what size, it largely depends on what your other splicing aspirations are, as you could fit even our large Wand into that rope. So if, for instance, your running rigging was 1/2" or less, get a Medium. Call if you need more information.
As for lashing material, you just want something fairly UV-resistant, and suitably strong. Seine twine of a suitable diameter would work, assuming a suitable number of turns for the size. Or you can use fewer turns of skinny Spectra, which has the added advantage of not having scuffable tar on it. Whatever material you lash with, don't use the absence of turnbuckles as an excuse to be approximate with your measurements; approximate-length lifelines look awful.
Fair leads,
Brion Toss

[Essington]

The splicing wand is a great tool for doing the tail bury. I have a medium wand that I just used to complete some splices on my dyneema (STS-HSR) standing rigging.
For smaller diameter line i usually just use a piece of folded stainless mig wire.

But you will want something like Brion's oak handled marlingspike for creating the brummels. It works really well for most sizes of line. The taper of the spike allows you to open up a hole just big enough to pass the end or a bight through.

-jason

[rdykiel]

Thanks for the replies, order following, Happy Holidays!

[rdykiel]

Hi I want to make lifelines in 1/4 dyneema and I ordered AmSteel AS-78. Should I have ordered STS-12 instead? All in 1/4".

Thanks

[allene]

Originally Posted by rdykiel

Hi I want to make lifelines in 1/4 dyneema and I ordered AmSteel AS-78. Should I have ordered STS-12 instead? All in 1/4".

Thanks

This stuff is so much stronger than what you need that for sure the stanchions will break before the line. But there is creep in Amsteel and probably in AS=78 so pre stretch it before making the lifelines or you will be adjusting them often. Just tie both ends to two cars and try and drive away ;-)

[rdykiel]

Thanks - AmSteel and STS-12 have the same breaking strength (8.5k lbs in 1/4) so I was wondering the difference. So many things to learn, so little time :-)

[Brion Toss]

Hi again,
Actually, STS is much stronger than the Samson (12,000lbs vs 8,600), but the most significant difference for this application is constructional stretch, which isn't stretch at all, but rather the effect of strands settling into place under load. For the Samson, you can likely count on about a foot for every 50ft. of run; for the STS, a third or less of that.
Note also that your splices will cause the rope to shorten by an inch or more, again depending on the material, as well as the length and degree of taper in your splices. A little experimentation will reveal how much shrinkage you get from your splices.
Ain't learning grand?
Fair leads,
Brion Toss

[rxc]

I am doing the same project for my boat, and have a problem with one of my gates. It is only about 23 inches wide, so I cannot do the standard 72 diameter bury on both ends . I am using 7mm dyneema.

Does anyone think that it would be OK to do a 36 diameter bury on each end and then stitch the tails and sieze the throats of the eye splices? This gate is across the stern of the boat - not the sides.

Edit: I just realized that I could also do a Brummel splice with a short tail, which could even be stitched, as well. Any thoughts?

Edit 2: Upon more thought, it has finally occurred to me that I could use a long bury eye splice to insert a thimble around the bails on my bow pulpit, where the original lifelines were attached. I have found a source for 316SS thimbles that are not closed, so it appears that I could make the eyesplice around the thimble and thru the bail, thus eliminating the need for lashing. I could even stich this splice for extra safety. Does this sound like it would work? I have an eye-stud at the other end to do adjustments on the lifeling tension.

[benz]

For something like lifelines, especially with such thick line, you need not take the bury to 72 diameters. A neat trick is to taper shorter than the 72 diameter splice allows, then have the tapers overlap one another a little in the middle of the standing leg. I have tried making this sort of thing with no taper at all so that the line ends butt against each other inside the piece, but unless you can put a serious load on before you trim the ends of the buried lines, it's very hard to get just right.
However,for your purposes, a brummel and short bury should be just fine. I always like to put a whipping on even a brummelled splice.
Ben