Destruction test of old Vectran

[Benz]

Did some destruction testing on bits of old Vectran off my boat (all my standing rigging is currently poly-covered Vectran); here are the results:
a piece of super-fuzzy, sun-cooked, ten-year-old, uncovered vectran broke at 4,000# Originally it was rated at 12,800#
Another piece of poly-covered, ten-year old, always outside line broke at 6,000# That's still less than half of the original published break strength of 12,800#.
The line was New England Ropes' V-100, 3/8" diameter, which puts the core at about 1/4" dia.
The covered piece parted near the center of the line, nowhere near either spliced end. The uncovered piece parted at the end of the splice bury, which I hadn't bothered to taper since it was just supposed to be a temporary bucket lanyard, which is why it sat in the weather for years and years getting yellower and fuzzier.
This bears out what others have said about covered Vectran losing strength over time in the sun. I was surprised by the break location on the covered line--I had expected it to be at the end of a splice taper, even though I normally taper the splices down to one strand.
I'll break more pieces if I get a chance....

[fgd3]

Try breaking a new piece, too. You want to know if it was age or UV exposure that caused the line to break way below its rated strength or if the line never lived up to its specifications.


Fabbian

[Benz]

^^ Good idea. I only wish I had a new piece to break. I bought that spool ten+ years ago, and used it all.

[conachair]

Originally Posted by Benz

I'll break more pieces if I get a chance....

Would be really interesting to see what dyneema with UV coating like marlow d12 max breaks at after a decade in the sun.. might have to wait a decade though
Thanks for sharing

[Benz]

^^ word around the water is that dyneema is far more impervious to sun damage than Vectran. The Vectran got fuzzy just from being out, without being abraded by anything or even under load. We get some old covered halyards in the shop where the Vectran inside is crumbling to dust; this happens also with Technora cores. The worst I've seen dyneema cores do is get moldy, and maybe fuzz a little. But the fuzz is far from catastrophic by the time the cover is in a scandalous condition.

[Benz]

Broke another piece of Vectran: this time 7/16" Validator II. Almost six years in full-time weather and under tension (this was a jibstay). Published BL: Just over 15k #
Broke at just over 11k #. The break was along the body of the line, not near any splice. Interestingly, there was a significant recoil when the piece broke (it was over 40' long.)
The rest of my standing rigging is this same stuff: if it all has more than 10K breaking load left, so I'm not too worried yet, given my low-aspect-ratio gaff rig and ten-ton boat.
Still, if I get a chance to go long-term again, or if looking at a leisurely RTW, I'd prob'ly want DUX or DM-20.

[thinwater]

The published breaking strength is normally the minimum breaking strength; the average breaking strength is generally 10% greater than that (I've tested many).

The cover material and color makes a great deal of difference. A white polyester cover is kind of like a white cotton tee shirt; not good at blocking UV. Typically, the core is nearly as UV damaged as the cover. Even Sunbrella is not perfect in white. Thus, always go for dark colors for UV blocking. I've tested a lot of rope cores, and the cover never does as much as you expect.


I actually had a Kevlar sheet fail inside the polyester cover, without the cover breaking! I just noticed a lump during a walk-around inspection.

[s/v Jedi]

Aging is the problem with Vectran, especially UV exposure. I had to retire all my Vectran running rigging after 10 years, while Dyneema (Amsteel Blue) just keeps going.

The problem for you when you switch to Dux: Vectran has much less creep, check the dux tables for creep. You will probably have to go up one size.

[Benz]

Originally Posted by thinwater

The published breaking strength is normally the minimum breaking strength; the average breaking strength is generally 10% greater than that (I've tested many).

The cover material and color makes a great deal of difference. A white polyester cover is kind of like a white cotton tee shirt; not good at blocking UV. Typically, the core is nearly as UV damaged as the cover. Even Sunbrella is not perfect in white. Thus, always go for dark colors for UV blocking. I've tested a lot of rope cores, and the cover never does as much as you expect.


I actually had a Kevlar sheet fail inside the polyester cover, without the cover breaking! I just noticed a lump during a walk-around inspection.

This was gray/blue cover. I think if I was looking for ultimate longevity, I'd Maxijacket the poly cover with black, then use a Dyneema anti-chafe cover on the whole length. By then, of course, the price difference between Vectran and Dux would have been negated.

[Benz]

Originally Posted by s/v Jedi

Aging is the problem with Vectran, especially UV exposure. I had to retire all my Vectran running rigging after 10 years, while Dyneema (Amsteel Blue) just keeps going.

The problem for you when you switch to Dux: Vectran has much less creep, check the dux tables for creep. You will probably have to go up one size.

My rigging doesn't have much pre-tension: gaff-rigged pole mast. And with lanyards rather than turnbuckles, I could tune out creep for a long time, especially if I started out with lanyards rather long. I give the rig quick tune every spring on a chilly day, but it's never slack; it's just that twanging on my lanyards is part of my spring routine.

[slug]

Originally Posted by thinwater

The published breaking strength is normally the minimum breaking strength; the average breaking strength is generally 10% greater than that (I've tested many).

The cover material and color makes a great deal of difference. A white polyester cover is kind of like a white cotton tee shirt; not good at blocking UV. Typically, the core is nearly as UV damaged as the cover. Even Sunbrella is not perfect in white. Thus, always go for dark colors for UV blocking. I've tested a lot of rope cores, and the cover never does as much as you expect.


I actually had a Kevlar sheet fail inside the polyester cover, without the cover breaking! I just noticed a lump during a walk-around inspection.

Torque is also a failure mode

Every time you load a rope on a winch you introduce twists into the rope

These twist drastically reduce the strength of the rope

Somewhere on the internet is maximum twists per meter table for visually inspecting rope

[Boatguy30]

Don't see much well used running rigging over 10 years myself in the tropics. Must be some extra special stuff Jedi has.

Very impressed by that 11k break. I may have mentioned in another thread that Chicago Yacht Rigging broke a 5 y/o stores indoors winter's dyneema double braid and it was a bit under 50%. Same deal, broke near middle.

[s/v Jedi]

Originally Posted by Boatguy30

Don't see much well used running rigging over 10 years myself in the tropics. Must be some extra special stuff Jedi has.

The Vectran was shot at 10 years. It was 3/8” Yale Cordage with UV protectant coating, plus significant parts had a polyester cover.

The Dyneema running backstays are 3/8” Samsom Amsteel Blue. No covers at all, installed in 2004 and still good. My runners are just for sail shape... if they were needed to keep the rig up, I would have replaced them already.

[Benz]

Originally Posted by slug

Torque is also a failure mode

Every time you load a rope on a winch you introduce twists into the rope

These twist drastically reduce the strength of the rope

Somewhere on the internet is maximum twists per meter table for visually inspecting rope

I feel fortunate to have never twisted up my standing rigging during use.

[Boatguy30]

Sure, stripped Vectran? Forget it. Covered, will last just as long as covered dyneema. And maybe longer than dyneema covered dyneema.