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Chockstone Photography
Australian Landscape Photography by Michael Boniwell
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Chockstone Forum - Gear Lust / Lost & Found

Rave About Your Rack Please do not post retail SPAM.

 Page 1 of 2. Messages 1 to 20 | 21 to 31
Author
Old gear destruction
mikllaw
10-Nov-2014
10:56:26 AM
Experiment:- I had a static rope of unknown age ( I have never used or owned a new static, this might be the remains of rope given to me in 1997, retired from window cleaning) with a small rip in the sheath (diagonal, 30 mm long) that the core bulged out of. From interest I kept using it, abseilling then jumaring to prep route. I was also clipped to a double overhand knot tied about 6m below the damage as a backup. After 3 uses I was jumaring up and when I got the top jumar to the damage, the sheath ripped. I took a 1.5m slide till the sheath bunched (possibly on the knot below). Further jumaring wouldn't work as the core flattens into spaghetti (I cou;ld have prusicced on the 4mm string I keep on my harness). I abseilled down without much further sheath slippage, even when undoing the overhand knot that may have jammed the sheath. Phil Box suggested that I hand stitch some tape over the hole and keep using it...




SO what interested me about the dodgy static rope was just how fragile the sheath was. Is this environmental exposure (UV, oxidation, increasing crystalinity with age) and mechanical damage (abrasion, fatigue), and do these 2 factor potentiate each other?

Anyway, I bought a new static and it's been soft, shiny, and manageable. And doesn't squeak and spit dust when I rap.
Cross -posted from the Rope Test Lab Facebook page
mikllaw
10-Nov-2014
11:02:48 AM
I also looked at my old home-sewn slings (1994?) on my ascendeurs , particularly in the light of Richard Delaney's research on the Rope Test Lab where he found nylon slings more than 10 years old were all below half strength.
The loops at the ends were also very worn so I thought failure would occur there or in the stitching.



We were all surprised that the sling went in a relatively undamaged area away from ends, wear points, or stitching, at 5.7 kN, almost a quarter the strength of the original tape.



IdratherbeclimbingM9
10-Nov-2014
2:21:34 PM
Thanks for the informative (& scary), info posts mikl.
Richard Delaney
10-Nov-2014
2:48:30 PM
I have put up the whole report on the members' section of my website:

http://www.ropelab.com.au/old-slings/



But, yes, most of the single nylon quickdraws (now 20 or so) that I have tested that are over 10 years old have broken at around half of their rated strength. Some of my old WildCountry rigid slings were still pretty strong but...

Replace your old nylon draws - they're not that expensive!
gfdonc
10-Nov-2014
3:07:40 PM
Yes, scary stuff, and thanks.
But does the same apply to dyneema?
Richard Delaney
10-Nov-2014
3:19:44 PM
I have not tested much of the dyneema/spectra/kevlar/aramid stuff as it has changed significantly in the last 20 years - and there's just not that much 'old' stuff lying around to test.
gfdonc
10-Nov-2014
4:05:22 PM
Re: dyneema.
I have half a roll of the stuff that's been sitting around in a box for at least 10 years, but when Mikl tested some slings made from it a while back they all broke above 20kN.

But then I'm assuming the nylon issue might be linked to UV exposure?

IdratherbeclimbingM9
10-Nov-2014
6:34:11 PM
On 10/11/2014 Richard Delaney wrote:
>I have not tested much of the dyneema/spectra/kevlar/aramid stuff as it
>has changed significantly in the last 20 years - and there's just not that
>much 'old' stuff lying around to test.

In what way has it changed?

I am prepared to donate a couple of dyneema quickdraws for testing, ... mainly to 'proof-batch' the (plenty of) remaining ones I have; ... assuming you are prepared to test them and give us feedback to this site.
Their age? It escapes me at the moment, but it would likely be close to 20 years...
I probably still have the original receipts to ascertain date exactly, if they have not faded to obscurity due their age!

On the basis of your testing to date (of various) as posted here, I shall be retiring my half dozen nylon slings of similar (or older) age!

IdratherbeclimbingM9
10-Nov-2014
6:55:14 PM
A different thought, so a different post.

Not long back, kieranl posted about retiring his 28+ year old jumars, due his reluctance to trust the plastic engagement-retaining clips from doing their job.

Does your facility have the ability to test such things?

If not, do you have an opinion about such items?

(As an aside, although I am open to empirical evidence; ... my gut-feeling is that even if the plastic is beyond a hypothetical use-by date, the continued usage of such items is valid, depending upon a thorough knowledge of their useage and limitations, ... even 'if' a component of them is deemed potentially 'dodgy' by some).
mikllaw
10-Nov-2014
7:24:25 PM
Old nylon (pre 80s) was very badly affected, I think they added something which reduces this. However I've tested some gym draws, and Black Diamond tested lots of draws from caves that saw little UV but still broke at low loads.
Abrasion, cyclic fatigue, oxidation, crystalisation (nylon is amorphous and with time it may go into a more regular atomic pattern which can embrittle it) may all be part of the answer.
maelgwn
11-Nov-2014
3:17:38 PM
I also have a bunch of old dyneema/nylon blend slings that I have retired. Age and history unknown, but I would guess over 10 years old and relatively light use. I can send them if you are interested.
climberman
11-Nov-2014
4:49:57 PM
Thanks for this info guys, hadn't really occurred to me. Might well replace my older set of draw slings.
dalai
11-Nov-2014
6:18:29 PM
On 10/11/2014 Richard Delaney wrote:
>Replace your old nylon draws - they're not that expensive!

All nylon even if stored in the dark a number of years?
climberman
11-Nov-2014
9:15:28 PM
Richard do you want a bunch of different brand doggones/draw slings of various brands and vintage to play with? Happy to post em.
Richard Delaney
12-Nov-2014
11:45:44 AM
I'd love to increase the sample size if anyone has old draws in any condition they like to retire/donate.

If anyone wants to help out please post your old draws to:
RopeLab
PO Box 193
Katoomba NSW 2780

I'll happily "dispose" of them for you.
If you have the chance it would be great to include a bit of history with each:
- approx. purchase date
- approx. number of days used/year
- intensity of use (ie regular short falls/dogging routes or trad/rarely loaded)
- regular sea cliff vs mostly inland vs indoor
- anything else you may think is relevant

Richard
mikllaw
12-Nov-2014
1:53:52 PM
On 11/11/2014 dalai wrote:

>All nylon even if stored in the dark a number of years?

I really don't know what the degradation mechanisms are, sometimes slings are obviously abraded or faded. There could be time dependent changes in the structure of the nylon with time even without use or UV, I'd expect strength reduction to be slower with this than with heavy use.
grangrump
12-Nov-2014
2:21:56 PM
On 12/11/2014 mikllaw wrote:
>I really don't know what the degradation mechanisms are, sometimes slings are obviously abraded or faded. There could be time dependent changes in the structure of the nylon with time even without use or UV, I'd expect strength reduction to be slower with this than with heavy use.
Chemical degradation is also possible without light (and without bathing in battery acid...).
Studies on parachute nylons suggest humidity is more important than oxidation but there is a synergistic effect of oxygen and humidity on degradation.
Be careful rapping of those old slings in canyons?!

mallion
18-Nov-2014
1:31:36 PM
On 12/11/2014 Richard Delaney wrote:
>I'd love to increase the sample size if anyone has old draws in any condition
>they like to retire/donate.
>
>If anyone wants to help out please post your old draws to:
>RopeLab
>PO Box 193
>Katoomba NSW 2780
>
>I'll happily "dispose" of them for you.
>If you have the chance it would be great to include a bit of history with
>each:
>- approx. purchase date
>- approx. number of days used/year
>- intensity of use (ie regular short falls/dogging routes or trad/rarely
>loaded)
>- regular sea cliff vs mostly inland vs indoor
>- anything else you may think is relevant
>
>Richard

Do you need the whole draw or just the dog-bones?
mikllaw
18-Nov-2014
4:57:11 PM
Just the tape, the biners are great until their gates stop working (latching) properly
Notime to climb
18-Nov-2014
9:55:33 PM
Richard,

Some slings and dog bones coming your way. I will send a selection with notes as accurate as I can get them. I have a couple of draws from the late 90's, some used some not well used plus a few slings that have done a few alpine trips

I found a bag of unused slings in a backpack in the cupboard, probably been there 11 years, never been used I will send one of these as well.

I will be interested to see the results?

We had a friend of a friend come on a canyoing trip years ago, he worked at a materials testing lab. He was horrified at the condition of the fixed slings in the canyons. We removed a couple so he could test them. From memory the results were not that bad in terms of breaking strength?

I will put them in the post in the next few days.

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There are 31 messages in this topic.

 

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