End to End splice single braid dyneema to double braid polyester

[CJ13]

I want to end to end splice single braid dyneema to double braid polyester without significantly increasing the rope thickness.
I’ve seen the Premier Ropes utube which is great but significantly increases the thickness. Has anyone done what I want to do?

 

[roaringgirl]

Yes, I did this on my Genoa sheets. I used the method in this (free) app here: Rope Splicing - Apps on Google Play

The app is excellent and really useful to have on board.

 

[Deleted member 478]

Yes, I did this on my Genoa sheets. I used the method in this (free) app here: Rope Splicing - Apps on Google Play

The app is excellent and really useful to have on board.

Thanks for this link. Now installed. Yep, agree that it will be very useful

 

[PabloPicasso]

I couldn't install the app as iy was "made for an older versiin of android"

Anyone got a fix for this issue?

 

[Ian_Edwards]

I get the same message.

 

[roaringgirl]

I couldn't install the app as iy was "made for an older versiin of android"

Anyone got a fix for this issue?

There's something funny going on for you, I'm running it on Android 13, which is the latest stable version. On the playstore the app says it requires: "Android 4 and up". What version are you on? Do you have the option to install it despite the warning?

 

[KevinV]

I couldn't install the app as iy was "made for an older versiin of android"

Anyone got a fix for this issue?

Same here, on android 9

 

[Deleted member 478]

Those having install issues, may I suggest that you contact the developers. They are probably aware of this issue.

 

[Neeves]

I don't mind a bit of thread drift - I like to think I'm open minded.

But why do you want to splice dyneema to polyester?

Now I appreciate you are talking about splicing, and it is against the rules imposed by some that you you should stick to topic, but it maybe that you will achieve your objective by sewing, without any loss of strength. It can still be neat.

But one hesitates given the passion of the thread topic protectors.

However one would need to know the how's and why's to offer a solution and maybe permission to suggest a sewn solution.

Jonathan

 

[garymalmgren]

Hi Neeves.
This is a topic that I have been thinking about and thinking of asking.
I have wire to double braid halyards.
The sheeves are for the smaller diameter wire.
When I eventually have to replace them I am thinking of going for Dyneema to double braid.
The smaller diameter Dyneema will fit my mast top and mast exit sheeves.
For that end what is the sewn solution that you suggest?
iI it is easier, i will take that path.

gary

 

[CJ13]

Yes, I did this on my Genoa sheets. I used the method in this (free) app here: Rope Splicing - Apps on Google Play

The app is excellent and really useful to have on board.

I’ve downloaded the App from the App Store (IOS) no problem. It’s very good but they publish the same info on UTube, which is animated so easy to follow.
Unfortunately the end to end splice shown for single to double braid, #5.4 inserts the dyneema core into the DB and the DB core into the dyneema, which increases the thickness by the size of the dyneema.

 

[CJ13]

Jonathan,

Burying the DB cover in the Dyneema and sewing might be the solution- I need to think about it.

 

[Neeves]

Hi Neeves.
This is a topic that I have been thinking about and thinking of asking.
I have wire to double braid halyards.
The sheeves are for the smaller diameter wire.
When I eventually have to replace them I am thinking of going for Dyneema to double braid.
The smaller diameter Dyneema will fit my mast top and mast exit sheeves.
For that end what is the sewn solution that you suggest?
iI it is easier, i will take that path.

gary

I'm in a rush, again. Thinwater is the sewing expert - he may be along soon.

If you are using sheaves for wire you need to ensure the sheaves are smooth or they may damage the dyneema. When I replaced my main halyard of wire to dyneema ) changed the shelves - but its easier to do that if you take the mast out. I did not find this but it may be that your sheave box can be replaced directly with a new box for rope - I had to enlarge the slot - its not that difficult. My new sheave accepted 1/4" rivets which were a devil to secure. This was 40 years ago on an X-99.

Jonathan

 

[thinwater]

The usual method (with variations) is to trim the DB to length, plus the length of the cover bury (~ 4-6 inches), and then use the DB core to pull the length of Dyneema (longer by the amount of the Dyneema-only portion) through. The DB becomes a cover donor. and the old core is discarded. The cover is buried, and the transition lock stitched. No fatter than the double braid and full strength. Done it many times.

You are not going to find a method that does not make the line fatter, since the Dyneema and DB must overlap to be full strength ... obviously.

Sewing Dyneema single braid is not generally successful.

[It's not really full strength in many cases. If the cover slips on the core the cover will fail. Good on a winch, less sure in a jammer.]

 

[Neeves]

The usual method (with variations) is to trim the DB to length, plus the length of the cover bury (~ 4-6 inches), and then use the DB core to pull the length of Dyneema (longer by the amount of the Dyneema-only portion) through. The DB becomes a cover donor. and the old core is discarded. The cover is buried, and the transition lock stitched. No fatter than the double braid and full strength. Done it many times.

You are not going to find a method that does not make the line fatter, since the Dyneema and DB must overlap to be full strength ... obviously.

Sewing Dyneema single braid is not generally successful.

[It's not really full strength in many cases. If the cover slips on the core the cover will fail. Good on a winch, less sure in a jammer.]

To engender an overlap you could thin, edit - taper , the two cores, then overlap them


I may have missed it but why can you not accept an increase in the size of the cordage at the splice,

If I have the application correct then the splice of halyard when at full hoist will be at the mast foot, or you can arrange this to be the case - so why the concern over the size of the splice?

Slippage of a dyneema core in a cover is not unusual - this commonly happens at the clutch. The usual solution is to hold the halyard on a winch - not a clutch (been there done that). You need spare winches, or can arrange that a winch is always spare, maybe cross sheet.

Jonathan

 

[AntarcticPilot]

In much the same position (wire halliard with braid-on-braid tail) I simply replaced the whole length with a single length of dyneema. Why introduce a splice, which is necessarily a weak point and inevitably of greater diameter than either the dyneema or the tail?

 

[lustyd]

Why introduce a splice

Racers do this to save weight aloft. I agree with you, but reasons do exist whether you think they are reasonable ones or not. Even straight cruising dyneema will be lighter than steel wire though

 

[thinwater]

Remember that the friction requirement on end-to-end splice is 2x that of an eye splice (in an eye splice each leg carries 50%). The splice is going to be long and tight. If I wanted to save money I would use one piece of Dyneema and find a good used rope for the cover. Often retired Halyards have good lengths that were inside the mast.

 

[KevinV]

Racers do this to save weight aloft. I agree with you, but reasons do exist whether you think they are reasonable ones or not. Even straight cruising dyneema will be lighter than steel wire though

I'm interested in this because I currently have 8mm braid on braid halyards (and jammers to match), but have been given some dyneema - if it'll splice/ sew onto the braid on braid I can get two halyards out of the length, with 95% of the working length being dyneema. No worries about it slipping in the jammers, and still have different coloured ends to pull on.

 

[Neeves]

I'm interested in this because I currently have 8mm braid on braid halyards (and jammers to match), but have been given some dyneema - if it'll splice/ sew onto the braid on braid I can get two halyards out of the length, with 95% of the working length being dyneema. No worries about it slipping in the jammers, and still have different coloured ends to pull on.

If you can arrange that the splice never reaches the clutch then the need for the thin splice disappears (I think). You can easily overlap the two cores - and sew for more security. You may also find that even with a slightly large splice it will pass through the clutch.

If the worry is weight aloft - then the dyneema is going to be thinner (or its a similar weight to the polyester). If the dyneema is thinner then the splice will also be thinner (than if both pieces of cordage were the same). The only rigging we changed to thinner, dyneema, was the third reef, all the other running rigging, except for a spinnaker halyard, is covered dyneema (well overstrength) its 10mm for ease of handling. We also changed to single braid dyneema on furling lines - so as to get more cordage on the drum (and spliced on large, thicker, double braid tails (inserting the single braid into the polyester cover of the tail having removed the polyester core (and sewing).

We sew down the length of the splice and then sew again at right angle to the first set of sewing. We use braided dyneema fishing line to sew.

The discarded cores and sometimes covers makes good lines for fenders or sail ties.



As a complete aside - I decided to Brummell splice some spare double braid polyester. I wanted to make some Barber hall lines with 4 spare LFRs (for trimming lines on a big headsail). It was almost impossible and I resorted to bashing the work with a wooden mallet (could have been a rubber hammer). It took all night to make one splice. In the same time I could make 3 or 4 splices in dyneema. Dyneema is more more slippery. I had fondly thought that I could make soft shackles from polyester - I've discarded that idea. It may depend on the double braid but the double thickness of core you drag through - at the fid - seems to simply be too big. I have made double Brummel splices, one at each end, of short strops in Dyneema - its easy - polyester, I have better things to do

I have found making splices in dyneema strangely addictive. I now know why there is so much interest in soft shackles - its very satisfying to make them (and other splices) with dyneema - you then need to find (invent) more and more applications.

Jonathan