# Dyneema eye splice



## bobmcgov (Jul 19, 2007)

The Samson website makes it look suspiciously easy -- taper the bitter end, shove it up the middle of the standing line, and exit to one side. Cross stitch, you're at 90-100% of rated strength.

Am I missing something, or is it that simple to eye-splice a Class2 12-strand line? I need a bridle to serve as split backstay. Should I add thimbles to the eyes? One will be shackled to a chainplate, the other to a boomvang. Dyneema (3/8" Amsteel Blue) is okay to run over a 3"d block, yes/no?

If splicing it is really this simple, I can save $40 and do it myself. If not, the pros can do it.


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## bestfriend (Sep 26, 2006)

Not simple at all. I am pretty good at splicing, but that stuff is hard to do right. Even when I take it to the pros, it can come out too long or too thick. Tricky stuff in my experience. I should ask for clarification, are you talking about the dyneema core line or just the dyneema itself? The dyneema itself is not hard to splice. You're link does not work.


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## jimmyb116 (Feb 20, 2007)

use the instructions on the marlow site much stronger it is easy but you need to practice on scrap first


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## jimmyb116 (Feb 20, 2007)

also no on the thimbles only required on kevlar core


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## bestfriend (Sep 26, 2006)

Okay, i got the link, that one is easy.


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## sailingdog (Mar 19, 2006)

BF-

Be aware that if you're trying to splice a double-braid line with a dyneema core, you have to use a core-to-core splice, instead of a normal double braid splice, since most of the strength of a dyneema-cored line is in the core.

I'd recommend looking at the NE Ropes site, for info about how to do a *core-to-core splice*.


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## SailorMitch (Nov 18, 2005)

Very timely thread for me. A friend bought a whole spool of Warpspeed and is cutting lengths of it for several of us who want some new halyards. My main halyard is Sta-Set X, which is OK but still has more stretch than I want. The Warpspeed will improve that a lot. I already have the Wichard shackle and want to splice it on as soon as my friend cuts the line. I did buy a piece of Warpspeed at Fawcett's in Annapolis for cheap (end of a spool) and will practice on that first. Been a long time since I spliced anything but would like to tackle this one. Thanks for all the pointers.


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## jimmyb116 (Feb 20, 2007)

I would suggest stripping the cover, as it is heavy on warp speed and not required for the halyard, just leave enough cover so that when the sail is fully hoisted the cover stops at the mast base. Also Use the splicing instructions from the Marlow site much stronger eye splice. Don’t forget to lock stitch or it will creep on you.


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## sailingdog (Mar 19, 2006)

I wouldn't strip the cover, even if it is a bit heavy. The cover acts to protect the inner core from UV damage and abrasion.


jimmyb116 said:


> I would suggest stripping the cover, as it is heavy on warp speed and not required for the halyard, just leave enough cover so that when the sail is fully hoisted the cover stops at the mast base. Also Use the splicing instructions from the Marlow site much stronger eye splice. Don't forget to lock stitch or it will creep on you.


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## jimmyb116 (Feb 20, 2007)

Warp speed is designed to have the cover striped the core is treated to be UV proof and abrasion resistant.


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## KeelHaulin (Mar 7, 2006)

Splicing Instructions for Samson rope is located here:

Samson

You should follow the instructions for the particular type of line you are splicing because cover (and sometimes core construction) varies between manufacturers. The reason that the Samson lines (and others) require a core-core splice is because the cover is tightly stitched and you can't bury both the cover and the core into the neck of the eye (it's too thick to pass the cover through). Since the strength of these lines is mostly in the core a core-core splice will retain 90% of the strength of the line.

In terms of difficulty; it's about the same in terms of time/effort to do a core-core VS a standard eye splice. Both type of splices are tedious and if you can't do it from memory (lots of steps) you have to read the instructions as you go. The difficulty in the core-core splice is getting the core splice to milk back into the cover; and whipping the excess cover tightly to the eye. Cutting dyneema/vectran to taper the strands is not easy either. You have to saw on it (won't cut even with the sharpest scissors); it is tough stuff!! It's easy to cut it as a solid line but cutting the individual strands is a chore. I don't think 25 bucks to have someone make eyes is unreasonable; but it's a good skill to know how to DIY also.

Stripping the cover WILL reduce the useful life of the line to a large extent. For halyards you can reduce the wear by replacing the cover at the eye so that there is a 1-2' length where the line has a cover (to prevent chafe on the masthead sheave and cut-through of the line on the shackle). If you strip the cover you should also run messengers so that the exposed section is stowed in the mast and out of the sun which (will deteriorate the exposed core). The wear/tear on halyards with stripped cover is just another "boat buck" expense for serious racers. I won't strip the covers on our halyards because we are not competetive racers. You can strip the covers on spinaker sheets so that you reduce weight of the lines pulling down on the sail in light wind (helps the sail 'fly' better).


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## jimmyb116 (Feb 20, 2007)

I guess KeelHauling and I aren’t going to agree, and do to the fact this is not for my boat I can’t be bothered getting into it, so do what is best for you bobmcgov best of luck.


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## SailorMitch (Nov 18, 2005)

Since it is my boat, I appreciate your comments, Jimmy. I've printed out the Samson, New England and Marlow directions for splicing dyneema lines. Working from the old joke that a camel is a horse designed by a committee, I fear what kind of splice I'll end up with. But seriously, I have a test piece of Warpspeed to play with and will try a couple of them to see what will work for my limited skills in this area. I do want to keep the cover on (just because), and I will lock it down with stitches. Again, thanks for your comments.


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## JimsCAL (May 23, 2007)

I replaced my main halyard (dacron to wire) about 5 years ago with a Warpspeed one. Had the eyesplice done by Defender's rigger. Very happy with it.


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## bobmcgov (Jul 19, 2007)

jimmyb116 said:


> I guess KeelHauling and I aren't going to agree, and do to the fact this is not for my boat I can't be bothered getting into it, so do what is best for you bobmcgov best of luck.


No worries, JimmyB -- this thread has actually turned into a fairly broad and disheveled forum on splicing options and methods, which is dandy. My *original* question was about eye-splicing 12-strand Amsteel Blue -- a hollow (coreless), single-braid line. Since the manufacturer endorses a simple splicing technique, I'll take their word on it. Tho it might be fun to pull-test an offcut w/ practice splices, just see (unscientifically) how much it can take. If it can budge the tractor, it'll do for the backstay.


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## jimmyb116 (Feb 20, 2007)

If you have problems take it to a rigger a backstay is a terrible thing to lose at the wrong time. Did that but got lucky and didn't lose the mast.


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## bobmcgov (Jul 19, 2007)

jimmyb116 said:


> If you have problems take it to a rigger a backstay is a terrible thing to lose at the wrong time. Did that but got lucky and didn't lose the mast.


Per class rules (tho I'm not terribly bothered by those) there will be a safety cable backing up the adjuster. Not sure how that would fare in a shock-load, mind you. It may however prevent blushes while raising the mast if yours truly forgets to attach something important.

I'm overdesigning this thing pretty seriously -- replacing 1/8" wire rope with components at least twice (and up to five times) the cable's breaking strength as SWL. Should still come in under $250: nice people at Garhauer. (Thanks SD for the referral.)


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