Dyneema brands, standing rigging, UV and chafe

[seandepagnier]

$103 for a quart and no mention of UV?

[s/v Jedi]

Here: https://www.velasailingsupply.com/ya...ijacket-quart/

[thinwater]

Originally Posted by fxykty

Regarding a Y-splice, wouldn’t that simply be an eye splice, then cutting the line in the eye to get the two legs? If so, then the Y angle should be same as the throat angle of an eye - less than 15* for Dyneema for example. That would generally be a very high Y - much higher than usual. Rather than the cost for all that extra Dyneema, why not end the backstay with a low friction ring or terminal, then lead the single Y line through that fitting and to the two corners? That’s only the cost of a single piece of hardware.

It will weaken the one leg about 30%, right where the line exits. This has been tested.

[thinwater]

Chafe covers vs. thicker line. Dyneema and Spectra chafe sleeves, have FAR better side-to-side chafe resistance than 12-strand Dyneema. It is the difference in weave, just as chafe guards for nylon and polyester rope are made from webbing (different weave). Climbing rope has a different weave from marine ropes for the same reason--sawing chafe resistance.



I have tested 12-strand Amsteel vs. NER WR2 of the same OD, and after a number of cycles on the side-to-side chafe machine, WR2, with the smaller core, was about 35% stronger.


Sometimes you have to think beyond what seems obvious. Chafe is about weave more than fiber.

[seandepagnier]

Originally Posted by s/v Jedi

Here: https://www.velasailingsupply.com/ya...ijacket-quart/

Availability: Custom made in about 6 weeks


Hmm... If I mostly care about UV not abrasion why not use standard paints such as rustoleum mentioned?

[Jolly Roger]

Try Miami Cordage at: www.miamicordage.com

[thinwater]

Originally Posted by seandepagnier

Availability: Custom made in about 6 weeks


Hmm... If I mostly care about UV not abrasion why not use standard paints such as rustoleum mentioned?

Adhesion. UHMWPE is very slippery and not much sticks well.


Regarding coating is general: I'm not sure how many of these will affect creep if applied heavily before installation. You may be in for a big nasty surprise. I would not paint standing rigging unless I had done a bunch of testing. Until then, it is all theorizing. These paints are intended only for mooring eyes.

[s/v Jedi]

On UV protection: any pigmented substance provides UV protection. This is different from UV filters which are used for transparent coatings.

Even when you mix pigment with the thing you want to protect (think pigment in epoxy like gelcoat) then the pigment protects the epoxy. Kind of.

Adhesion is one thing; changed characteristics of the Dyneema are a bigger worry I think. This is why I prefer Amsteel Blue: it has proven it’s UV resistance for me… even though I also notice that the coating has changed over the years.

The Yale coating has a very good reputation afaik.

[Mexican Hat]

I didn't feel like reading through the whole thread so someone may have posted this already, I found UHMWPE rope at a pretty decent price in comparison to everyone else in the US I checked. Back when I was planning my rigging (with a limited budget) I could get swaged stainless wire shrouds made up for about 20% of what the equivalent in Dynex Dux would have cost. And that was without any of the very expensive fittings that go along with the dux line. I was able to buy a 200m spool of heat treated and coated 9mm dyneema for about the same price as the stainless. I got it through David Van der Spuy at rigbos.com/aka Bosun Yacht Services. If I remember it was called GP12. At least then he didn't seem to have it on the webpage but if you ask he can give you the details. A German company built a factory in Cape Town for manufacturing this sort of rope. They also have amazing prices on 8 strand anchor line.

The other thing about dyneema is that it is really easy to splice. Once you get a feel for the process it's far simpler, I think, than any other rope type.

And as a slight aside, did anyone figure out a way to get Trukote 100? I will be happy with the anticipated 10 years of life from factory coated dyneema and so don't want to use it for that but I do need a plastic paint for sealing foam cushions. I do have some plastidip but haven't tried it yet. And fyi, a gallon of plastidip was about $90 at one of the US big box hardware stores.