End to End Splice -- UNEQUAL size Dyneema

[Dockhead]

Anyone have any idea whether this is possible for not? I want to splice some 8mm single braid to a piece of 12mm double braid which has a 6 or 7 mm Dyneema core. It seems to me that the big rope inside the small will be no problem, but no idea whether the small rope will be held in place inside the big one. Grateful for any tips.

[billknny]

Originally Posted by Dockhead

Anyone have any idea whether this is possible for not? I want to splice some 8mm single braid to a piece of 12mm double braid which has a 6 or 7 mm Dyneema core. It seems to me that the big rope inside the small will be no problem, but no idea whether the small rope will be held in place inside the big one. Grateful for any tips.

The assumption here is that you are using Dyneema because you will be looking at fairly high loading (otherwise, why spend the very significant $$$$?)

The simple answer is NO. You can not be sure of making a high strength splice, no matter which way you go.

On the other hand if this is for an unloaded halyard tail, it doesn't matter...

[conachair]

Would a dyneema/doube braid polyester splice work?

https://www.youtube.com/watch?v=aohGiTNCMQE

[thinwater]

^^ Yup, done that. A great penny pincher trick. Yes, it has been tested at near full strength. Typically, however, it's not highly loaded or you would want continuous HMPE.

[Paul L]

Here's another dyneema single braid to double splice that is different from the one conachair posted
http://l-36.com/halyard_splice.php
I used this for my topping lift.
The premiumrope one looks cleaner and easier to do.

Why use dyneema on the thick portion?

[Dockhead]

Originally Posted by thinwater

^^ Yup, done that. A great penny pincher trick. Yes, it has been tested at near full strength. Typically, however, it's not highly loaded or you would want continuous HMPE.

I think "penny" is not the right word here -- it's a $400 racing dyneema outhaul. If the splice is near full strength, then it will be stronger than the eye splice on the end, so I don't see why I would insist on a continuous piece.

[Dockhead]

Thanks to everyone for the helpful suggestions. I ended up doing it like the halyard splice. We'll see how it works. But it looks pretty good. I'll sail 250 miles on it tomorrow and the next day -- should be a decent test.

[thinwater]

Originally Posted by Dockhead

I think "penny" is not the right word here -- it's a $400 racing dyneema outhaul. If the splice is near full strength, then it will be stronger than the eye splice on the end, so I don't see why I would insist on a continuous piece.

I place no negative connotation on "penny inching." And yeah, it can be hundreds!

[Dockhead]

Originally Posted by thinwater

I place no negative connotation on "penny inching." And yeah, it can be hundreds!

Cheers.


But why would you write "it tests at near 100% strength ,but typically it's not a high load application, or you would want continuous" etc. Isn't that a contradiction? If it test at near 100% strength, why would you prefer continuous, if you have some reason to splice?



I have spliced dyneema all over my boat, in critical high load applications. All my sheets and halyards, running backs, you name it -- if it has to carry tonnes of load, it's spliced dyneema. Not end to end splices (this is the first one I've ever done), but eye splices for sure. I trust my life in a climbing harness, to spliced dyneema ropes (no "high load" jokes please ). In fact almost every bit of running rigging on the boat is made of either single or double braid dyneema, with eye splices. Spliced single braid dyneema is far stronger than knotted anything, and as far as I know, they approach 100% reliability -- I don't think I've ever even heard of a failed dyneema splice.


Or is there something I haven't heard of?