Dyneema

Cerebus

Cerebus

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Just read that dyneema (also called spectra) was invented in the 1960s but not commercially viable until 1990s.

It made a huge difference to my sailing or sailing practicalities and the ease of splicing is brilliant.

I remember splicing 3 strand rope and it was painful to the mind and fingers.
 
Cerebus said:
Just read that dyneema (also called spectra) was invented in the 1960s but not commercially viable until 1990s.

It made a huge difference to my sailing or sailing practicalities and the ease of splicing is brilliant.

I remember splicing 3 strand rope and it was painful to the mind and fingers.
Click to expand...
3 strand is easy compared to Marlowbraid or similar. We are big Dyneema users too, our boat would perform poorly without it.
 
I am considering swapping out the large diameter braid lines joined to stainless wires - which serve as halyards on my 38 - to all through Dyneema.

Have to measure up and decide diameter of the Dyneema .... being less diameter _ am looking for the locking clutches to work better. At present they are probably maxed on rope diameter - causing the handles to be a high angle when used.
 
We have 8mm for probably similar areas and loads. We previously had a wire/rope jib halyard, no clutch issues. We managed to acquire almost our whole inventory as end of reels, some colours might not have been first choice, LOL, but the price definitely was.
 
Refueler said:
I am considering swapping out the large diameter braid lines joined to stainless wires - which serve as halyards on my 38 - to all through Dyneema.

Have to measure up and decide diameter of the Dyneema .... being less diameter _ am looking for the locking clutches to work better. At present they are probably maxed on rope diameter - causing the handles to be a high angle when used.
Click to expand...

Dyneema uncovered does not stick very well in jammers.
But its extremely easy to taper / add covers / bulk up in way of jammers if you have some basic splicing tools.

On my boat I have a Selden boom with internal sliding cars for the reefs / outhaul etc. I tapered the lines so that they're uncovered internally & covered externally (where exposed to UV etc), the whole system runs much better.
 
" Dyneema uncovered does not stick very well in jammers."

Years ago I was in Portugal when two big racing yachts were preparing for what was obviously a significant event in the racing calendar. The crew were 'skinning' some of the Dyneema running gear and I was lucky enough to be given quite a few lengths of the outer sections of rope. I never used it as gear for my Gaff Cutter, but it served for just about every lashing purpose I needed. In fact some is still used as a trailer load lashing years later.
 
veshengro said:
" Dyneema uncovered does not stick very well in jammers."

Years ago I was in Portugal when two big racing yachts were preparing for what was obviously a significant event in the racing calendar. The crew were 'skinning' some of the Dyneema running gear and I was lucky enough to be given quite a few lengths of the outer sections of rope. I never used it as gear for my Gaff Cutter, but it served for just about every lashing purpose I needed. In fact some is still used as a trailer load lashing years later.
Click to expand...
Our jib, kite and code 0 sheets are tapered. We never run short of dinghy painter or washing line.
 
veshengro said:
...I was lucky enough to be given quite a few lengths of the outer sections of rope.
Click to expand...
Oh, the joys of making up your own Soft Shackles from ^ and substituting just about everywhere possible. I now have yet another big box of shiny stainless shackles which are now redundant.

It's kinda nerdy. And even my good friend Sarabande is asking 'how do you do that?'....
 
Like Chiara, I mostly have off cuts , ends of lines Dyneema from ebay and local riggers.
Just wondering if anyone has used it for jib sheets. I like the idea of lightness. Would probably have to be a minimum of 10mm. I wear fingerless gloves all the time now so not too worried about abrasion.
 
All our sheets are dyneema. It’s energy saving in the end, there is a lot less sheet adjustment through the gusts. Appreciate that many cruisers don’t trouble with that, but it affects our main leech tension disproportionally because of the number of purchases, the amount of line available to stretch, and the loading. If our leech isn’t sheeted to the centreline, we just can’t point. Dyneema gives us a stable shape, without it hooking as the gust passes. That is even more disastrous. Not to mention that the battens won’t flip when you tack. In short, we find it a huge advantage. Anyone with a fair sized jib/genoa, most particularly a laminate sail, would gain as much with the jib sheets. The competitive Contessa 32s use it round here, the big overlapper needs to be stable for them to perform as well.
 
MontyMariner said:
You will probably have to change the sheaves as well if they were ment for wire.
Click to expand...

Its questionable as the data sheet I found for the boat indicates all rope ... nothing about wire.

Quote :

If you need to renew parts of your running rig and is not quite sure of the dimensions, you may find the estimates computed below useful.



Guiding dimensions of running rig
Usage
Length​
Diameter​
Mainsail halyard
36.3 m​
(119.1 feet)​
12 mm​
(1/2 inch)​
Jib/genoa halyard
36.3 m​
(119.1 feet)​
12 mm​
(1/2 inch)​
Spinnaker halyard
36.3 m​
(119.1 feet)​
12 mm​
(1/2 inch)​
Jib sheet
11.4 m​
(37.4 feet)​
14 mm​
(0.55 inch)​
Genoa sheet
11.4 m​
(37.4 feet)​
14 mm​
(0.55 inch)​
Mainsheet
28.5 m​
(93.5 feet)​
14 mm​
(0.55 inch)​
Spinnaker sheet
25.1 m​
(82.3 feet)​
14 mm​
(0.55 inch)​
Cunningham
3.9 m​
(12.6 feet)​
12 mm​
(1/2 inch)​
Kickingstrap
7.7 m​
(25.3 feet)​
12 mm​
(1/2 inch)​
Clew-outhaul
7.7 m​
(25.3 feet)​
12 mm​
(1/2 inch)​

Unquote

I know quite a few boats that have changed without altering mast sheaves ...

I'm due a trip to masthead soon anyway - to replace the broken windex ... will have a look then.
 
Snowgoose-1 said:
Like Chiara, I mostly have off cuts , ends of lines Dyneema from ebay and local riggers.
Just wondering if anyone has used it for jib sheets. I like the idea of lightness. Would probably have to be a minimum of 10mm. I wear fingerless gloves all the time now so not too worried about abrasion.
Click to expand...

I use 4mm dyneema for my four jib sheets, fitted to a club foot jib, but as it's only 35 sqft that's probably not much help for your use.
 
Hello Nigel. I would stick with the existing wire with rope tail if it is all in reasonable condition. If it needs replacement then go dyneema/spectra.
Now currently I have a similar dilemma with the main halyard on the little boat. 21ft. I replaced the wire with rope tail jib halyard long ago. Started with 6mm od dyneema with polyester cover. It did seem to stretch after setting so went for 8mm OD which seems better but still occasionally needs to be retensioned. A bit of a pain using hank on jibs and dropping jib on spin run.
Now the wire haliard for main sail needs replacing. I followed you tube re splicing a new rope to the old wire. Got new rope. had a devil of a job getting old splice apart. great difficulty opening up the strands of wire to get old poly out.Could not get the old tapered wire into polyester outer due to many tiny strands of 7x19 popping out. Through the tape. Then realised that i would have almost no chance of opening up the lay of then 3/16 7x19 to get strands of poly through. So yes gave up.
I will buy 18m of dyneema. Guy on youtube makes it look so easy.
Not sure if dyneema no cover would suit. Would UV degradation be a problem. I would abandon the clutch in lieu of horn cleats. I have dedicated winch for main halyard.
Supplier is offering 10mmOD covered dyneema. but I am not sure it will fit inside mast crane. Will check that. Pulley at top is quite narrow. great for wire. Myb thinking is to go about 6mm bare dyneema. If necessary I could perhaps add a poly covering for bottom part. But major part uncovered will be exposed to sun when on mooring.
Interesting the supplier (good price) actually weaves the rope to order. I havee used his 5mm dyneema bare for back stay and trailer winch very successfully.
I would appreciate any advice though true to tradition I will probably ignore good advice and do it my way. ol'will
 
Dyneema does not suffer, or its minimal, from UV degradation. When Dyneema was first introduced it was bundled together with Kevlar and Kevlar suffers badly from UV. Experience now shows that was a phurphy - but the warnings persist.

Its amazing how incorrect information outlasts the correct data.

Many have swapped wire for uncovered Dyneema for their lifelines - there have been no reports of any issues from UV. Dyneema short, closed, interconnected loops of uncovered Dyneema tape are used to make soft chains (the chains are not harsh as would be found with wire or chain). Tape is increasingly being used in lifting, again replacing chain, many tape slings are Dyneema - no issues with UV.

Dyneema is a 'wonder' product. There are downsides, its not perfect - heat is an issue, its very slippery - but accomodate the downsides and it is a wonder product. You don't need to have a high tech racing yacht to find applications. 10mm seems far too big for your sails - I appreciate you need to handle said cordage - gloves and 8mm would be better and 6mm about right :) or splice on bigger tails.

We used dyneema sheets for all our sails (our largest was 45m^), covered (too many ways raw dyneema could be abraided reciprocally and melt) and we inserted each sheet end in to hollow dyneema tape to join, and sewn with braided dyneema fishing line, the 2 sheets together and then cow hitched to sail (the join lasted longer than the sail).

Your backstay should give you confidence.

Go for it.

Jonathan
 
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My wire to rope halyards appear ok .... but until I get to see the part that resides inside mast - I cannot be sure. Wary of removing to check condition ... getting the splice to run clean over the sheave can be frustrating.
Visible sections of wire and rope appear in good condition. But the size is max for the clutches ....

Trying to splice old wire and even old rope is a nightmare and hard on the hands ! Its one of those jobs that its better to use all new or buy in professionally made to measure.

Thinking of halyards - I've been searching everywhere for the shroud halyard cleats I bought a while back ... to create flag halyards on the 38 ... can I find them ? If I buy another set - they will magically appear again !!
 
Cerebus said:
Just read that dyneema (also called spectra) was invented in the 1960s but not commercially viable until 1990s.

It made a huge difference to my sailing or sailing practicalities and the ease of splicing is brilliant.

I remember splicing 3 strand rope and it was painful to the mind and fingers.
Click to expand...
A HK perspective

We were using Dyneema in the very early 90's. Halyards (except spinnaker) and sheets, main, jib, genoa and spinnaker (we also had some lightweight 2mm Kevlar sheets for the spin in light airs). We bought reel lengths (which meant an awful lot of the running rigging was red and later red or blue. It was fabricated by Bridon and was used on Rothmans who stripped off the outer covers where possible (fears of UV damage). I'd like to say it contributed to our successes - that would be wrong, we won because we were good. :) - we have the trophies.

You only need one wire to rope splice failure for motivation to change, though we were more strongly motivated by weight and the dangers of wire when a single strand fails

Dyneema is like carbon (sails).

When Dyneema was introduced it was expensive (and new). It was wrongly categorised as being UV susceptible. Now its on many yachts, its common place.

An update from Oz

Carbon sails are/were much the same - when introduced they were rejected by the 'weekend' leisure sailor. Where Class rules don't restrict they are replacing Dacron and laminates. They are increasingly seen on 'cruising' yachts (though they might also 'race').

Carbon needs special care, so does, or did, laminate - after a race, in the 90's we stripped off all the sails and rolled them (loosely), held in a long sausage bag and stored along the cabin sole - same, same. Class rules demanded a Dacron main, allowed laminate head sails, we had a laminate main made for events where class rules did not apply (some RORC Blue Water races).

Jonathan
 
Hello Nigel. I have sort of decided to go for dyneema halyard perhaps 5mm spliced to 10mm polyester. You tube seems top make a splice easy.
I will report in due course on success or failure. I could go all dyneema but small diameter required to suit mast top sheave (for wire) will make handling and cleating more difficult. So will try splice ol'will
 
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