Dyneema brands, standing rigging, UV and chafe

[earthbm]

Looking for a 600’ spool to replace standing rigging on a 50’ trimaran.

Samson Amsteel 1/2” seems to be the same price as New England 3/8” And about 20% cheaper than New England 7/16”. If they are all made by DSM, why the difference?

I need 7/16”, maybe 1/2” (more windage and creep, but peace of mind, etc).

So:

1) does anyone have a good line on 600’ spools?

2) any real world data on the differences between Samson, New England, others? This Practical Sailor article shows some difference, but not conclusive.

I am also thinking of getting the Dyneema Chafe Sleeve for UV protection... More windage and 50% more overall cost though. Would increase the life by 50%? Alternatively, is it not the same as getting a double-braid with the same Dyneema core?

[Breaking Waves]

Originally Posted by earthbm

1) does anyone have a good line on 600’ spools?

2) any real world data on the differences between Samson, New England, others? This Practical Sailor article shows some difference, but not conclusive.

I am also thinking of getting the Dyneema Chafe Sleeve for UV protection... More windage and 50% more overall cost though. Would increase the life by 50%? Alternatively, is it not the same as getting a double-braid with the same Dyneema core?

regarding the sleeve - you are rather better off just getting a bigger diameter line with a much higher initial strength, than putting on a sleeve that adds no strength and is not all that good UV protection. If you simply want UV protection, a plastic coating (or wrap) is the way to go - thinner, lighter, better UV protection and (usually) cheaper.

As to brands, idk, I use Samson and Cortland Plasma (there are several flavors of the plasma line, used mostly in industrial use, not recreational). They are both highly reliable and you can get big spools.

[Benz]

Although all Dyneema comes from DSM, there are at least four grades of it, useful for different purposes, and braided/coated/treated in different ways by different manufacturers. The favorite for standing rigging is pre-stretched, heat treated SK75, such as Dinyce Dux. You can also get heat-set SK78, SK99, and DM20 from Marlow. Maffioli makes a really nice dyneema-covered heat-set SK99 called "Ultrawire," whose quality is reflected in the price.
I'd think the standard flavors from Samson would be too stretchy for standing rigging, but NER has a heat-set option that would do. Any NER dealer could get you a spool given enough lead time. If you know the specs of what you need, I can look in the catalogs and see what line/diameter you need.
My choice for standing rigging would be, in order of awesome:
Dynice Dux ($$$)
Maffioli Ultrawire ($$$$)
Heat-set DM20 ($$)
Heat-set SK99 ($$)
Plain SK99 ($)
Heat-set SK78 ($)
NER heat-set

[seandepagnier]

I am looking at the heat set dyneema because it has more strength for the windage even if you don't care about stretch.

I have found on defender and velasailingsupply a few options, but it would be great if people can post links for other sources.

I think the sleeve makes sense though, even if it adds a small amount of diameter, because you can replace the sleeve, and having a thicker line is not perfect, because the strands on the outside go to the inside so uv weakening has an effect here.

There are also coatings I have found, but I cannot find where you can order these special coatings.

I will probably keep wire on the furler for now because if the wire does not resist twisting, it can unscrew the turnbuckle that is integrated into the furler which has no way to lock this.

What about shock loading if some stays are metal and others are dyneema? dyneema changes tension with temperature which causes shock loading when the mast moves more, and this is not normally a problem for dyneema but I am concerned it can weaken the stainless which normally must have a much higher tension to avoid this.

[Breaking Waves]

Originally Posted by seandepagnier

I think the sleeve makes sense though, even if it adds a small amount of diameter, because you can replace the sleeve, and having a thicker line is not perfect, because the strands on the outside go to the inside so uv weakening has an effect here.

Well, a few facts:

(1) if we start with 12mm amsteel just as an example - 15,400kgs avg breaking strength.
(2) we put a cover on it and it becomes 16mm (look at the strength of the double braid 16mm amsteel II plus) which simply maintains the base strength
(3) If instead we go to 16mm amsteel we get 24,000kgs breaking strength, a 56% increase, which will cover a lot of both potential UV and chafe, and give you less stretch and creep.

Many people think a cover offers near 100% UV protection to the core but IT DOES NOT. If you take a double braid that has been UV exposed and separately test the core and cover, you will find they have both lost almost equal strength. Samson tests suggest UV will penetrate and damage thru 4mm of cover, and you will note that there is (only) 2mm of cover thickness in the example above. The covers do offer decent chafe protection and that is their primary value - NOT UV protection.

Testing has equally confirmed that coatings can offer UV protection, much better than braided covers. The various coatings available do vary, some are quite good for 2 years and then flake/rub off and you need to recoat; while some are quite long-lasting (but harder to apply). But if you look at the textile runners and checks on good race boats, they will often have a coating.

[earthbm]

Originally Posted by Breaking Waves

Testing has equally confirmed that coatings can offer UV protection, much better than braided covers. The various coatings available do vary, some are quite good for 2 years and then flake/rub off and you need to recoat; while some are quite long-lasting (but harder to apply). But if you look at the textile runners and checks on good race boats, they will often have a coating.

Could you point us to the testing results, if online?

What coatings are long lasting?

Is there a good creep/stretch table for 1/2” sk78 and others? I need to know how much lashing is needed for my 75’ cap shrouds?

[Breaking Waves]

Originally Posted by earthbm

Could you point us to the testing results, if online? What coatings are long lasting?

Simple questions to ask, rather harder to answer - you have dozens of products, with a whole range of potential UV and other environmental conditions which affect the test outcomes. Some of these coatings are 100% UV block until actively chafed off - they have to be because they are used on PBO and vectran which are super UV delicate (PBO particularly), and some of them (like maxijacket are about 50% block for 2 years (in some sort of normal usage conditions) and declining from there, but are pretty easy to recoat.

You can get UV test results for most of these products from the manufacturers. Collected cross manufacturer results in one document is rather harder to find - @Thinwater 'might' have something. I have some from tests done about a decade ago (when I was involved with North Sails) but the products have changed since then (and they were proprietary)

Is there a good creep/stretch table for 1/2” sk78 and others?

Pick a line and look up the datasheets, virtually always for a reputable manufacturer, the stretch and creep numbers will be there.

need to know how much lashing is needed for my 75’ cap shrouds?

You are aware you will have significant constructional stretch and splice growth to deal with before you get to load stretch and creep? Do you know your static and dynamic loads? You can't get to creep and stretch without those.

I don't know your boat, I don't know any details of your rig, I am reluctant to give you specific product guidance with this lack of knowledge. The outcomes for doing this wrong are not very pretty and doing it right needs a bit more than spitballing. What I said in my post above about covers and coatings is simply basic textile rigging knowledge.

.........

[Benz]

Originally Posted by earthbm

Could you point us to the testing results, if online?

What coatings are long lasting?

Is there a good creep/stretch table for 1/2” sk78 and others? I need to know how much lashing is needed for my 75’ cap shrouds?

Marlow has a section on their site describing creep and stretch, but the tables seem to be missing just now, though the spaces for them are there. Might have to shoot them an email and ask.
Meanwhile, if you size your shrouds so that they're not taking more than 15% of BL, you should pretty much eliminate creep. For 1/2" (well, metric half inch, which they call 12mm), I have from the Marlow catalog:
Heat-set SK78 break load: 39,665 pounds
Heat-set SK99 break load: 46,013 pounds
Heat-set DM20 break load: 35,620 pounds

As you see, half-inch is stupid strong for your boat, but if you send me a target break load, I can find a line that fits. The least-creepy one from Marlow will be DM20, and is available in 110-fathom spools (they call it 200M)

[goeasy123]

I heard on of the YouTube channels quote that UV only impacts a very thin outer layer and stabilizes quickly and for a long time. Might have been Rigging Dr or Free Range.


Thoughts??

[Breaking Waves]

Originally Posted by goeasy123

I heard on of the YouTube channels quote that UV only impacts a very thin outer layer and stabilizes quickly and for a long time. Might have been Rigging Dr or Free Range.


Thoughts??

hmmm . . . wrong

UV degradation continues progressively over at least a 10 year period. very few tests have gone longer than that, but I expect it simply continues. It is faster over the first 24 months and then the rate of degradation progressively slows somewhat but it does continue.

It very roughly reduces the strength by anywhere from 40% to 60%.

And in a single braid, it affects all the fibers, as (as someone correctly mentioned above) the fibers all come to the surface at some point along a length of single braid line. And as I mentioned Samson testing suggests it will penetrate 4mm down from the 'surface', so 100% of the way thru an 8mm line even not taking into account all the fibers coming to the surface along a braid.

UV is a real and significant effect and you have to factor it into your engineering, you can not ignore it as a minor factor . . . except in applications where you have so oversized the rope that a 50% loss is not important (which with Dyneema being so strong is not all that hard to do).

[earthbm]

My static load at capsize is 6600 pounds. Times 5 = 33,000 lbs, so 1/2" SK-75 or better could work. To keep the break load under 15% as Benz suggested, I'd need 44,000 lbs, so for creep considerations (where dynamic loads don't play a big role) heat set 1/2" SK99 or better is needed (46,000 lbs less 10% for splices). Or maybe go to 9/16" size in SK78?

I imagine dynamic loads could be x1.25 or x1.5 the static loads (just guessing shock loads in case of a Chinese gybe of something similar)?
So if UV degrades the strength 50%, I am still okay at 22,000 lbs vs shock loads of 10,000 lbs.

Is any coating better than Yale Maxjacket?

[Sailorman97]

Replacing stainless steel with rope is not something I would do. What is the worst thing that can go wrong on a sailboat other than being holed? Your mast falls over. If your racing exotic ultra light and fast boats sure. A cruising sailboat? Sorry. This is not even a thought for me.

[Breaking Waves]

Originally Posted by earthbm

My static load at capsize is 6600 pounds. Times 5 = 33,000 lbs, so 1/2" SK-75 or better could work. To keep the break load under 15% as Benz suggested, I'd need 44,000 lbs, so for creep considerations (where dynamic loads don't play a big role) heat set 1/2" SK99 or better is needed (46,000 lbs less 10% for splices). Or maybe go to 9/16" size in SK78?

I imagine dynamic loads could be x1.25 or x1.5 the static loads (just guessing shock loads in case of a Chinese gybe of something similar)?
So if UV degrades the strength 50%, I am still okay at 22,000 lbs vs shock loads of 10,000 lbs.

Is any coating better than Yale Maxjacket?

Maxijacket is an easy to get and easy to apply, and quite flexible coating, and thus great for DIY.

It is not 'the best' possible coating, and the high end rigging companies use different 'better' solutions - like this for PBO stays:
But you would have difficulty duplicating this.

There are 'intermediate' solutions, many of which are less flexible than maxijacket (but more lasting and more UV protective), but that is ok for a stay so long as you have room to work on it. TrueKote CS 100 is one example I have used. There are quite a number of products like this with varying characteristics.


On the rope - you have a bit of a trade-off. There are some products like DM20 with essentially zero creep but they are slightly weaker per diameter than SK75/78. I would think DM20 the better technical solution for stays, but any of these will work, and I am not aware of any really good comparative data on their actual performance in this application. Dynice DUX (heat set SK75) probably has the most active installations because it has been around the longest (of the heat set 75's) but it is getting a touch long in the tooth today.

I will comment that I am personally in the 'it is hard to beat SS rigging for a cruising boat, and you probably should only do Dyneema if you have really compelling reasons (which in a cruising context usually is is not an extra .1kt) and also know a lot about what you are doing". I say this as someone who knows a reasonable amount about both cruising and dyneema. But this is just me, and I understand other people will have different perfectly valid perspectives leading them to give Dyneema stays a try.

[Benz]

Originally Posted by earthbm

My static load at capsize is 6600 pounds. Times 5 = 33,000 lbs, so 1/2" SK-75 or better could work. To keep the break load under 15% as Benz suggested, I'd need 44,000 lbs, so for creep considerations (where dynamic loads don't play a big role) heat set 1/2" SK99 or better is needed (46,000 lbs less 10% for splices). Or maybe go to 9/16" size in SK78?

I imagine dynamic loads could be x1.25 or x1.5 the static loads (just guessing shock loads in case of a Chinese gybe of something similar)?
So if UV degrades the strength 50%, I am still okay at 22,000 lbs vs shock loads of 10,000 lbs.

Is any coating better than Yale Maxjacket?

If your shrouds are set up nice and tight, a chinese gybe won't shock load them much: it's the boom end that gathers speed and stops suddenly, which is why it's booms that break in those scenarios. But even if a gybe shocked the shrouds, and you've put a 5:1 safety margin on, you've got plenty of margin.
It will take close to ten years to lose 50% of the strength, maybe you keep up on it and lose even less? I had certain chafe points on my synthetic rigging wrapped in vinyl tape, and the tape lasted for years, and then I'd peel it off and put on more. You could exclude all light by wrapping in heavy vinyl plumbing tape, then sliding on a thin cover (could be polyester, for price's sake), thus saving a ton of money on the dyneema itself, which gets really expensive when you start talking half inch.
I wonder how much light vinyl tape excludes?

[Breaking Waves]

Originally Posted by Benz

I wonder how much light vinyl tape excludes?

Depends a lot on the specific tape, but I saw a test of a 2-layer wrap of the better 3m black “outdoor” tape and it was quite high protection.

That sort of tape wrap used to be a preferred approach by some of the better rigging mfg’s. They have moved on, not because of better UV but for more “hands off” for the user. The 'tape end peeling/hanging off" was just not a look that the high-end customers liked.