/ When to replace slings?

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Adderbury Climber - on 29 Aug 2017
How do people judge when a sling needs replacing?

All my slings look OK obviously, no visible damage, but I am aware they do degrade over time (even if stored in the dark). So how do you decide, just on date of purchase, number of days out, by inspection, or some combination.

If it's relevant I am thinking of long slings used for anchors, and some 60cm which I used for extended quickdraws.
Rob Morgan on 29 Aug 2017
In reply to Adderbury Climber:

Well, I'm no expert but I'd say it's a combination. If you no longer fully trust a sling then perhaps it should be replaced.

A sling I regularly place around rocks etc I would replace sooner than one of my alpine draws which get less abuse.
Coel Hellier - on 29 Aug 2017
In reply to Adderbury Climber:

Replace them when they are obviously furry (or have other visible defects; or, if they still look fine, after 5 yrs max).

Obviously this is merely an opinion.
CurlyStevo - on 29 Aug 2017
In reply to Adderbury Climber:
I think the degrade in the dark thing when store in a cool dry place is slowly being accepted that its not as was previously thought.. Blue titan have stored a length of new static and periodically tested it and there is no degradation in strength. Its doesn't really make sense either the materials in climbing gear would take a long time to degrade in the absence of other factors.

Some manufacturers have now upped the obsolescence time span for material items (disregarding other factors) to 10 years from point of purchase. I imagine as before that still allows for 5 years on the shelves - which is unlikely to be that long IMO. This will still be conservative IMO.
Post edited at 18:10
Jonathan Lagoe - UKC - on 29 Aug 2017
CurlyStevo - on 29 Aug 2017
In reply to Jonathan Lagoe - UKC:

pretty much as expected storing nylon gear in the dark alone has almost zero degradation effect. I don't know of any tests on old unused slings but I suspect you'll see similar results. Ofcourse used gear is likely exposed to not only wear but a bunch of chemicals (sunscreen, insect repellent, natural stuff like tree sap, urine (!), etc) to what extent they have an effect over a long period of time is also somewhat unknown but I guess probably mostly a minimal effect if the chemicals in question don't soak the gear and the gear is washed at appropriate times ( and the chemicals aren't particularly aggressive like strong acid / base etc)
aracer - on 02 Sep 2017
In reply to CurlyStevo:

Really interesting stuff. I'd always assumed that textiles needed retiring after 10 years whatever use they'd had, and indeed having started climbing again after an almost 20 year break I've replaced all of my original soft stuff. Apart that is from my tricams - they're still sitting in the box of old climbing gear with their original slings because it seems reslinging them is too difficult and expensive (from what I can work out I'd need to send them to the US). But then I've seen a bit recently about textiles not really ageing when not in use, so was coming on here to enquire about the reality. I'm fairly sure none of them has ever been placed (I bought them just about at the point I stopped climbing) and they look in perfect condition. They've also spent that 20 years in the dark wrapped up in bags.

So given those test results would I be really stupid to use the 20 year old completely unused slings on my tricams?
CurlyStevo - on 02 Sep 2017
In reply to aracer:
Well those slings are nylon. I'm not going to say they are safe categorically... also bare in mind the stitching isn't nylon.... why not ask a manufacturer to pull test them. They may not want to though as it could effect their sales if they are fine ! I'm betting odds on they are fine but it's an unknown quantity.
Post edited at 01:12
aracer - on 02 Sep 2017
In reply to CurlyStevo:

Thanks for the reply - I got to thinking about them having been on a climb today where there was a gear placement which would have taken a tri cam, but I had nothing with me which would go in it. If I'd had it hanging on my harness I'd have placed it - even if the sling's lost half its strength (which is incredibly unlikely) that would have been enough for the sort of fall I might have taken onto it. I think I'm going to put them back in my rack, but not lend them out to anybody else (I'm climbing with people mostly new to trad some who don't have their own racks, so my gear sometimes gets lent).
SenzuBean - on 02 Sep 2017
In reply to Adderbury Climber:

I was told 4 years after manufacture by an experienced guide here in Canada. DMM say 10 years. As others said, the research says these are very conservative - basically if the sling looks and feels solid, and definitely has not been exposed to harmful chemicals - it’s probably good.
The one caveat is that a fuzzy sling is often weaker than a brand new sling that is cut in half! Pretty sure that was a BD gear test
mariopulquerio - on 02 Sep 2017
Offwidth - on 02 Sep 2017
In reply to aracer:

Maybe donate them to the BMC for testing? The results would be interesting and I suspect little strength will have been lost.

One thing that shocked me from the BMC was a test to destruction demo Dan M did at the Peak Area meeting (I wish they would put this on BMC TV). One new sling cut half through was stronger than a brand new sling rubbed hard on a lump of grit. Ask yourself if you would climb with a sling cut half through if you are happy to climb with a furry sling. If crucial webbing has been rubbing on rock (say harnesses with plenty of chimney use or more pertinently in-situ abseil points blowing in the wind on rough rock) it needs to be treated with caution. UV exposure can make a bleached sling weak enough to snap in your hand (I've done this with an old sling on an abseil point in Red Rocks). Use rope for multi-use abseil points, not slings.
Sean Kelly - on 02 Sep 2017
In reply to Adderbury Climber:

The really critical test for a sling is ...would you be happy to ab off it? What is your life worth...the price of a sling!
MFB - on 02 Sep 2017
In reply to mariopulquerio:


Really useful link - massive fan of 6mm dyneema slings, great pro and many other uses, cheap
I was already considering replacing my oldest slings - grey and furry - their tests confirm my prejudice
Shame they didn't include the actual values.
CurlyStevo - on 04 Sep 2017
In reply to MFB:
I'd like them to have tested brand new slings stored for 10 years. Also I felt little use was hard to define and is a subjective measure.
jkarran - on 04 Sep 2017
In reply to Adderbury Climber:

When I start thinking it looks shabby and wondering how strong it still is it's time for a new one. Alternatively for the less cavalier: follow the instructions that came with it.
jk
jkarran - on 04 Sep 2017
In reply to aracer:

> So given those test results would I be really stupid to use the 20 year old completely unused slings on my tricams?

I'd use them without a second thought but then I might be stupid.
jk
Monk - on 04 Sep 2017
In reply to Adderbury Climber:

A few years back someone on here was doing a PhD on climbing gear and I sent him a load of my old gear. It all held over 10 kN, even the 20 year old heavily used slings (although only just and they were 22mm, I think). It was very reassuring. Basically, the more trashed something looked the weaker it was, but older stiff that looked new was still strong.
danm on 04 Sep 2017
In reply to Monk:

The trouble is, 10kN sounds strong, and it is stronger than say a Rock 1, but as soon as you knot a sling which is knackered enough to only hold 10 kN unknotted, you suddenly get a piece of gear which is not much stronger than a small micro nut. That's why it's important to read the detail in the DAV article linked earlier. Slings need more care than other gear partly because of their fantastic utility, which means we can use them either in ways which seriously weaken them (knotting them) or in ways which may subject them to huge loads (using them as a lanyard), or worst of all, both!
MFB - on 04 Sep 2017
In reply to danm:
Is there a lot of sling failures occurring?
If so what type
Post edited at 20:36
Mr Fuller on 05 Sep 2017
In reply to Monk:

Yes, that was me. Masters rather than PhD but same principle!

As you say, if something looked more tatty it was usually less strong, which was reassuring. From memory, everything exceeded about 18 kN apart from one dogbone that I'd found lying on the ground at Giggleswick. That failed at about 12 kN and I would not have wanted to climb on it.

The abrasion thing is really interesting and well worth taking notice of: if your big sling gets stuck at the back of a sharp grit boulder and you just yard it out, sawing it over the sharp edge you can easily cause a lot of damage: I've retired a relatively new sling when this happened.

The other thing to look for is what is holding the strain: as far as I know all slings still have very thin bits of nylon alongside the Dyneema content (it's easy to tell them apart because Dyneema can't be dyed so is always white; nylon is the coloured bit!). A sling's normal wear mechanism is that the nylon - lower strength - furs up as the fibres break. These fibres then help protect the Dyneema underneath, which itself has a mega abrasion resistance anyway. I wouldn't be too worried by the nylon getting a bit furred up as long as the Dyneema looks good, within reason obviously.

Finally, lighter weight gear doesn't last as long. 6 mm slings have half the number of fibres as 12 mm slings so we can probably assume they have half the lifespan in normal use. For general cragging there is basically no point in buying megalight slings and you'll save some money by buying fatter ones.
jkarran - on 05 Sep 2017
In reply to Mr Fuller:

I think you tested some of mine too, first generation 12mm dyneema-mix slings which were in my opinion very shabby looking after a decade of regular use. I forget the exact numbers but I do remember both were significantly degraded yet still stronger than most of the kit I used them with.

As with most things 'if it looks right it probably is' seems to work well enough unless one has a really cavalier attitude or exposes their kit to acids.
jk
Offwidth - on 05 Sep 2017
In reply to danm:

I suspect most climbers still don't properly realise what fall factors are, so the issue that a brand new unknotted sling will not hold a FF2 is not the massively obvious avoidable hazzard that it should be; let alone the extra risks of using old knotted slings as lanyards. Its why I'd like the BMC to show some of these sling demos on BMC TV.

If you clip directly in to an unknotted sling as the first runner of a belay on near vertical rock, then climb above it until the sling is tight, trying to clip a second piece, and then fall at that point the sling will be looking at close to a FF2 load (subject to any give in the harness) and may well snap. I've seen variations on this many times, with the leader shouting 'safe' after clipping the first piece then climbing up for the next; usually on slightly less than vertical rock but then often with old and/or knotted slings.
DubyaJamesDubya - on 05 Sep 2017
In reply to Offwidth:

> I suspect most climbers still don't properly realise what fall factors are, so the issue that a brand new unknotted sling will not hold a FF2 is not the massively obvious avoidable hazzard that it should be; let alone the extra risks of using old knotted slings as lanyards. Its why I'd like the BMC to show some of these sling demos on BMC TV.

> If you clip directly in to an unknotted sling as the first runner of a belay on near vertical rock, then climb above it until the sling is tight, trying to clip a second piece, and then fall at that point the sling will be looking at close to a FF2 load (subject to any give in the harness) and may well snap. I've seen variations on this many times, with the leader shouting 'safe' after clipping the first piece then climbing up for the next; usually on slightly less than vertical rock but then often with old and/or knotted slings.

If a 20KN sling will break under such circumstances surely a 12KN rated wire would.
Offwidth - on 05 Sep 2017
In reply to DubyaJamesDubya:

How would you do that in practice? If you mean the misused sling takes a fall factor 2 on a nut yes the nut (or rock) might well fail first. People need to watch this film and think on its implications:

https://www.youtube.com/watch?v=iJ5dN0ZSv7w

Its not just the breaking sling risk its the shock load on the body. Having slack in a sling based system is bad news.
Mr Lopez - on 05 Sep 2017
In reply to CurlyStevo:

> I'd like them to have tested brand new slings stored for 10 years. Also I felt little use was hard to define and is a subjective measure.

Agreed.

The importance they give to age as a marker in balance with use and condition without making more effort in quantifying the later is misleading, specially when there's a perfectly logical reason of why dyneema slings seem to loose strength 'faster' than nylon.

It's just that with dyneema being a stronger material the sling is composed of less fibres to achieve the same strength when new. The other side of the coin is that for each single damaged fibre a bigger percentage of strength is lost, . So if we conjure some round numbers for an example:

A single Nylon fibre takes 10grams, so you weave together 1000 fibres and you end up with a webbing that takes 10kgs.
A single dyneema fibre takes 100g, so you weave 100 fibres and you get a 10kg webbing.

Now you cut 1 fibre from each, and the nylon webbing will have lost 10g of its strength, so that's a 0.1% loss, whereas the dyneema webbing will have lost 100g of its strength, which is 1%. So every time you rub a sling across the rock those fibers you damage have a bigger impact if it's dyneema than nylon.

Dyneema is actually much more stable than nylon and most other man made fibres, and were age by itself be a factor, any strength loss would be less than that of nylon.

And for a bit of trivia, dyneema actually gets stronger with use/aging and even more so when being loaded hard. The more you load it the stronger it gets. Not much benefit when the sling looks like it's sporting an afro though
DubyaJamesDubya - on 05 Sep 2017
In reply to Offwidth:

Ah I see you mean: shock loading by falling straight onto a sling. Sorry I thought you meant using it as your first runner leading. That's not really a fall factor two though, it's actually worse, which is why the sling fails.
Offwidth - on 05 Sep 2017
In reply to DubyaJamesDubya:
Its not worse than FF2 on the sling (although if attached to a short length of rope the effect on the rope can be greater than FF2).

The youtube clip demonstrates the effects of FF1 and FF2 drop tests on new dynema and nylon slings that are open or knotted. The implications seem obvious to me: don't ever leave slack in a sling based system. Many slings in common use these days are narrower than those tested and older (time in use) and more damaged through abrasion or UV. I'd regard Mr Fuller's 'rather positive' test results with caution as he tested what he had. As I said above Dan M showed abraded new slings can be weaker than a sling cut half through and I've snapped a sun bleached sling in-situ on an abseil station in my hands.
Post edited at 14:50
Oceanrower - on 05 Sep 2017
In reply to Adderbury Climber:

When to replace slings?

The day before they break...
BarrySW19 on 05 Sep 2017
In reply to Sean Kelly:
> The really critical test for a sling is ...would you be happy to ab off it? What is your life worth...the price of a sling!

Not sure that's a great test - I'd be happy to ab off quite a lot of stuff that I wouldn't want to fall on. Euro Death Knots, and water-knotted tat for a start.
Post edited at 17:31
DubyaJamesDubya - on 06 Sep 2017
In reply to Offwidth:

Yes but I thought you were talking about FF2 leading on a rope as opposed to the direct falls onto a sling in the film. Thus the confusion.
RR on 10 Sep 2017
In reply to mariopulquerio:

Thank you for posting the report. Due to it I have replaced my very old Troll 2.40 meter dyneema slings and other WC, Squamish on sight and DMM dyneema slings as well. With a smile I am going to replace the dog bones on the quickdraws as well. Alpinistes sont habitué a prendre du risque.

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