UKC

I've recently acquired some 10 to 15-year-old slinged hexes and quickdraws. From what I've read, soft climbing gear can deteriorate over time. Considering this gear has never been used and has been stored properly, is it safe to use?

Upon visual inspection, they appear brand new with absolutely no signs of fraying, fluffing or wear. Mixed articles from climbing forums lead me to believe that this is a matter of personal preference, but I'm curious to hear what others think.

P.S. To preempt any questions, I am completely certain that this gear has never been used and has been stored in optimal conditions (no exposure to sunlight, mould, moisture, etc).

My hexes and some of my draws would have been bought around 2010 and I’m happy using them. Far from an expert though. 

Yes but if you are asking the question, you are unsure of it so no.

Would you happily let your mum use it for her next E9?

Certainly a fair point. Personally, I believe they're fine to use based on inspecting and seeing other people's gear, as well as reading online. The reason I'm asking is that I'm still a bit new to outdoor climbing, so I was looking for some more experienced opinions to see if they align with my own.

I like this line of thinking. I've heard a similar saying: "If you wouldn't hang your kids off it, don't use it." Personally, I think it's fine, but I'm very aware that I'm new to outdoor climbing and was looking for some more seasoned feedback on the matter.

I've been referred to some useful videos on the topic if anyone is interested

30 Year Old Climbing Gear Tested: https://www.youtube.com/watch?v=k9yZ7-aO6jE&t=448s&ab_channel=HowNO...

30 year old climbing dog bones: https://www.youtube.com/watch?v=u8Ol16yLJ1g&ab_channel=HowNOT2Clips

I'd use it, but I wouldn't recommend using it to anyone else. A bit of an oxymoron though, I suppose lol

Gear doesn't deteriorate simply over time. It deteriorates with wear or with chemical damage. If neither of these can have happened, it's safe. Manufacturers will assume some small degree of continued wear by use over time in coming up with a guestimated use-by-date, but if it's never been used there's no reason that any such replacement dates should be relevant.

It's a little more nuanced than a simple yes or no question. Are you willing to put your life on it never been used and stored correctly. Might sound a bit dramatic but that's what we're talking about 

Would you think twice about using a seatbelt in a 20 year old car? It wouldn't even cross my mind not to trust it. I'm pretty sure it's a fair comparison, but happy to be proved wrong!

I'd probably cut the slings off the hexes and restring them with cord which is dirt cheap, Needlesports sell it in the required length.  Perhaps also replace the dogbones on the draws which is cheaper than new ones, or just have a load of snapgates which can come in handy.

It gets more complicated when your belayer/2nd etc has to also trust their life to it.

As you are asking the question, you shouldn't use it regardless of whether it is technically good enough or not. As soon as you begin to question the condition of your gear, it is time to retire it. Some random strangers online saying it will be fine won't be there to hold your hand if you begin to question their judgement while you're on the sharp end.

I wouldn't use the hexes because they're hexes (sorry all hex lovers). I would use the draws if I needed them.

This is a fair argument. And one I don't really have a good answer for. I guess it comes down to the level of risk you are willing to accept. Most of us drive 1000s of miles a year, for many years hopefully without any serious incidents, so it doesn't 'feel' that risky. Climbing on the other hand - the danger is much more obvious. 

I think if a partner is not happy with gear in perfectly good condition like this is, then it is probably time to get a new partner rather than new gear. Or, better, educate the one you have not to be so silly.

I understand what your trying to say, but I respectfully disagree. Asking about gear safety is not only normal, but it's also an essential part of responsible gear management. Everyone should question the safety of their gear to ensure it remains in good condition and is retired when it's no longer safe to use. Getting advice from others, especially those with more experience, can provide valuable insights and help make more informed decisions. It's better to ask and learn than to assume and potentially overlook an issue. Plus, discussing gear safety helps raise awareness and knowledge within the community, which ultimately makes everyone safer.

How thoroughly are seatbelts tested in an MOT? Is it just a visual check for visible damage?

If the gear were well used and disconcertingly worn you might have a point, but they are effectively simply asking whether gear becomes unsafe when unused and properly stored, which is a reasonable question to ask. Hopefully they are now reassured that it is fine.

I think this is a good approach. You could get them gradually accustomed to using items that are beyond their normal expected life, but initially not including climbing equipment. For example, I have loads of tinned curry that is years beyond its use-by date. There’s some stuff in the freezer I don’t even remember putting in there. An out-of-date banquet would be sure to put their mind at ease. 

Yes, there is always a nice frisson of jeopardy when one discovers some sausages at the back of the freezer and it says "best before April 20th" and one has absolutely no idea whether that was this year or perhaps as early as about 2017.

I follow current affairs and the news daily unless out of signal.

I have never seen any report on seat belt issues other than not using them.

I have been using climbing gear for over 55 years. 

For the first 25 or so, gear came without instructions or shelf life recommendations.

Latterly , it became illegal to sell gear without individual info.

At the time it was introduced, as I recall, being in the trade, most UK firms were reluctant to include recommended life span. They managed to get unlimited life for metal but settled on 10 years for textile.

Personally, I tend to trash most stuff before 10 ( or probably 35 ) years but will use anything circumspectly . Until you can make that judgement, it is far easier, and legally safer to advise,   just following the written guidelines.

I think i've still got the odd quickdraw sling on my rack that i bought from you back in the eighties!  S'pose i ought to retire it...

A couple of small wires date back to that era as well (about £2-50 a pop?) and they look absolutely fine.

I'm still using gear I bought when I started climbing thirty years ago. Sadly, most of it's in much better condition than I am.

I would be surprised if I don't have stuff more than 10 years old in my harness, and both i and several other people are happy to use it. It ain't curry and it doesn't stay in the freezer and they're obviously pretty terrible analogues. 

"Safe to use" needs more context.

Recreationally?  At the discretion of the climbing group. I would absolutely not use it without the group being aware as this is clearly outside the manufacturers recommendation. 

Professionally? Absolutely not. 

Realistically? Get new soft goods.  End of problem.

Personally? A parallel example came up for me. I had the super light rocks involved in the recall.  I sent one set in and continued using another.  I told (or reminded) everyone I climbed with of their status. I used them only to protect myself in lead, never to protect another in the anchor.

Which is really to say, I used them for as long as it took to replace them.  So for my money, go ahead and replace them. 

I think the question is 'I've been told that the gear has been stored correctly and not used etc'. How much trust are you willing to put in the ex-owners statement? 

The OP stated it as fact, so I presume beyond doubt in this case.

In my life it would depend on who i was using it with.

I would probably happily climb on it.

But if working, i wouldn't,  purely because if anything every did fail, i am sure my insurers would use the age of the kit to avoid paying out.
That does mean that the folk i take out climbing,  end up getting to use some newer kit than i use myself!

That makes complete sense. Not because there's any difference in safety in either case. But because workplace legislation requires changing gear even when it's absolutely and completely safe to use.

I got this on the van a few years ago. 1st MOT too and we'd had it two years and never used it (middle seat)

Do not drive until repaired (dangerous defects):

Central Front Seat belt webbing significantly weakened (7.1.2 (b) (ii))

My hexes must be getting on for 15 years old. I don't get to climb that often so they are in very good condition. It hasn't crossed my mind to replace them due to old age. I'll belay off them with no concerns at all. 

But don't we "put our life" on gear having been used and stored correctly, even if it is not old, whenever we climb with someone be it friend or stranger? 

Seriously? I have never heard of anything similar before.

What did the belt webbing look like? Presumably it must have been visibly abraded, or similar? If not, what was the test result based on?

Yes, I think we were all just blissfully ignorant back then Had to think of Tut Braithwaite’s take on the matter in Mike Thompson‘s great article „Out with the boys again“ from Mountain 1976, reprinted in The Games Climbers Play:

Whenever I scrap a car I test the seatbelts. These are usually pretty old cars and I cut the seatbelts and use them to hoist the engine out. Never had one fail.

Not sure about ignorance then.

Lots of magazine and instruction book info available.

The biggest scare I recall, was that climbing ropes were only good for one or two years. Thankfully that advice was  updated after a few years to something similar to whats on new rope info today.

Whenever I scrap a car, I ring up the local yard, they come to pick it up and give me a few quid.

A static pull on a few 100 kg engine cannot compare to a high speed crash.

Seat belts are way over specced but they might as well be , otherwise they would not look correct, safe and comfortable.

Morbidly, I have heard  second hand accounts of crashed  aircraft seat belts intact with no pilot  body obvious.

I read this and thought, well, you wouldn't want it to be like cheese wire.

And then you said this:

Shudder.

Absolutely. That's why only climb with friends I trust or strong recommendations. It's worked well so far! 

I’ve got a #2 original friend with the original sling on it, must be at least 40 yo and has been used a lot in the past. I’d be interested in someone stress testing it  !

I'll hold your ropes, Jim.

This is my take - I would trust my own gear that was stored and looked like that. Not someone else's. 

Are you willing to put your life on a single piece? It's far more likely that a hex placement will fail than the sling failing due to old age. That's why we back stuff up.

Have you and Frog never abseiled off in-situ tat then?

This is the official guidance to MoT testers:

https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and...

Reference Mike-W-99's post timed 20:54 Sun, it doesn't clearly define "weakened".  I can't imagine that MoT stations have pull testing equipment so my guess is that, unless the thing falls apart in their hands (!), they'll be looking for obvious signs of abrasion and/or deterioration of the webbing.

Backed up and pull tested after visual inspection. I wouldn't if I was thinking I might put 5kn on it though. 

I make sure I've got two pieces between the ground and myself, I also can assess the rock quality myself and trust the soft goods involved. One piece might fail but the chances of two pieces failing is very remote. 

The key thing is, I'm in charge of the care of the items and know the history.

If I'm getting something from a third party, I don't know if ALL the items are as described

"Oh, I forgot about that cam - that's the one I inherited from Bob. I don't know the history of that one. Oh, and that other cam I found on a climb in the 80's - I really should have thrown that away" the guy says as he visits my hospital bed, "Shit happens though, sorry".



 

Except it doesn't happen though. As far as I'm aware there has never in the entire history of people scaling rock for fun been an incident where a sling or rope failed purely due to old age. If you can find any record that says otherwise, please let me know. 

https://www.climbing.com/news/broken-sling-caused-tahquitz-double-fatality/

Break testing

https://youtu.be/IpJtTRmg7Og?si=kC8gUWyxhwcwFQDp&t=264

That webbing is degraded because it spent years outside, not "purely due to old age", which is what Hooo asked for examples of and is the relevant thing to think about when wondering if gear that's been stored 'dark and dry' for 10 years is ok to use.

That sling in the report broke due to UV and weather exposure, not old age. A sling left like that will be trash in a lot less than 10 years, so the age is irrelevant. 

I can't watch the video right now, care to summarise it?

You are certain of the gear's provenance, so I see no problem. But reslinging draws and hexes is pretty straightforward, if you are in any doubt. I recently re-slung a set of well-used 20 y.o. draws and it was pretty cheap and easy.

There was a case where a sling was exposed to battery acid in the boot of a car - I trust myself not to make that mistake - I don't trust many other people not to have. If it's a really close friend I trust, yeah I'll be happy with that. If it's an acquaintance whose habits I don't know - I wouldn't risk it.

Tim

p.s. I've just found a paper on Nylon strength degradation. Over 10 years it seems to be about 10-15% strength drop depending on temperature. In a hot environment, that might be 20%. It appears that UHMWPE has slightly less loss but with an error that puts it in the same ballpark. Whether 10-15% is an issue is the question. For most uses I'm sure it's fine.. 

https://www.sciencedirect.com/science/article/pii/S0141391010002636

Possibly correct but probably more a function of most folk retiring soft gear after ten years, it wearing out before ten years or if older being used circumspectly.

In other words, the PPE system and common sense are working OK atm. Boring but important.

"p.s. I've just found a paper on Nylon strength degradation. Over 10 years it seems to be about 10-15% strength drop depending on temperature. In a hot environment, that might be 20%. It appears that UHMWPE has slightly less loss but with an error that puts it in the same ballpark. Whether 10-15% is an issue is the question. For most uses I'm sure it's fine.. 

https://www.sciencedirect.com/science/article/pii/S0141391010002636"

In pull tests of old soft climbing gear we are generally seeing the following:

- Assuming no exposure to adverse chemicals climbing gear is generally failing due to how it looks, if its faded, furry or both it tends to fail roughly on how bad it looks not age.

- Soft climbing gear that is brand new and stored is often showing little degradation in rated strength. If you look at the links above the 30 year old dog bones are failing on average at 95% or higher of the rated strength. Blue water found no degradation in static lines at 12 years old https://www.paci.com.au/downloads_public/PPE/13_Rope_shelf_life_PToomer.pdf.

Would I personally replace unused soft gear at 10 years old. If it was easy to replace then quite often yes. On something like a micro cam that has a more than beefy sling and would need sending back to the states for reslinging - no, too much hassle I'd only do that when it looks furry / faded!

So you're agreeing that age itself is not an issue, what matters is do you trust the person to have stored it properly? I think we all agree there. 

So to answer the OP, they'll be fine. They trust the person to have stored it properly 

The EX owner is a close friend who I trust completely so 100%. This is why I answered this question preemptively in the post.

Absolutely! Beyond reasonable doubt anyway. Unless my close friend is secretly plotting to kill me.

This is an encouraging summary of an interesting article for my specific case. The key being that the gear looks absolutely fine on visual inspection (No fluffing, fraying, or discolouring) and I'm sure of the storage conditions and usage history (or lack there of). 

It begs the question of those who say you're wrong to trust your friend so implicitly about this - how are they able to trust that new gear they buy from a shop has been stored and transported correctly?

And why don't we see climbing partners taking two complete racks and ropes to the crag, so each can lead on their own, trusted gear?

Thank you to all of you for your feedback on this. After reading all the comments, and looking at the info sources you have referred me to, it seems the general consensus here is that:

1. The gear is safe to use as long as it looks good (no fraying, fluffing, discolouration, etc) and I'm sure of its storage and usage history (which I am).

2. Climbing gear doesn't deteriorate to unsafe states just from age but from usage, exposure to moisture, sunlight, chemicals, abnormal temperatures, etc.

3. If anyone did still have concerns about their soft gear, re-slinging hexes and getting new dogbones for the quickdraws is a cheap and easy way to eliminate any doubts, assuming the hard gear is in good shape.

Thanks again for all your advice everyone!

Absolutely true we trust our climbing friends with our lives regularly!

A great point I've been thinking about during the course of this post. While manufacturers are likely to store gear properly for appropriate time third-party resellers may not be so wise. Can you be sure that the minimum wage staff at Go Outdoors have stored that gear correctly in the back rooms? No, but you trust that they should have.

I'm more worried that the rope I bought online was thrown into the back of a van with a car battery that someone else had ordered, and the latter leaked onto the former. I can 100% guarantee that the driver and their company wouldn't care less about this, even if they understood it was an issue. I would consider this a far higher risk than using a mates 20 year old hex. I still buy online, but wouldn't accept anything where the packaging was damaged.

A different spec of webbing, but I have a 15 year old rucksack, and a couple of years ago one of the straps suddenly snapped when I picked it up. The strap on the other side is still fine. On inspection, the fabric had gone sort of brittle. No idea if it had got some chemicals or something on it and I replaced it with some spare webbing.

I suppose I'm trying to say that you're taking a risk with old textile stuff. It might look and feel mint condition, stored somewhere dry, mild and dark, but do you 100% know it is still OK?

Personally when I started climbing most manufacturers said absolute max 5 years from date of purchase for soft gear, some now say 10. If you can easily afford it I'd personally replace the soft gear that is over 10 years old. 15 is getting pretty old and I wouldn't want to lead on a partners 15+ year old soft gear or trust their belays on multipitch made from it. I know its not really agreeing with the stuff I linked but some of this is based on feelings.

Even some metal gear becomes a grey area, what about metal items with a flexible wire component. These do tend to become more brittle with use and some cams are pretty hard to fully assess etc. Cam stems have snapped in the past because of this.

You will know more about how you feel about this once you use it. I recently replaced a bunch of textile gear as I'm climbing more with a heavy partner and some of my textile gear was over 10 years old. If it had failed and injured or killed him, well you get the picture, even if the fault wasn't the age of the gear I'd always wonder.

I really try to not rely on feelings when it comes to safety matters. I like to assess the evidence, and if the evidence contradicts my feelings, I work on changing my feelings. This process works both ways - sometimes I'll come to the conclusion that something I've been blasé about is actually a bit of a risk.

No we are not agreeing that. There are scientific studies that show nylon 6.6 does age with time. You can not simply disregard them. The mechanism according to the paper linked above without other factors is oxidative degradation.

The question is at what point should we start to consider this as a factor when gear has been stored unused in dark cool place? 

Ofc perhaps in the future more actual studies will show how we can slow oxidative degradation further but at this point firm evidence has not been provided on this thread regarding that, and certainly not that we can disregard it completely.

Well that sounds all well and good but the only proper evidence we have (which I accept should be done at more realistic storage temperatures), shows nylon 6.6 does age and get weaker with time. The evidence to the contrary has not gone through proper scientific rigor and is generally based on small sample sizes. Using circumstantial evidence as we both know is also weak. That's why if you are going to disregard manufacturers guidelines your feeling about the safety of the gear does play a part as there is not enough information to go on evidence alone.

When you are on the sharp end or protecting a second you care about, feelings do come in to it. That nagging doubt about the strength or history of the gear is something most people can not just disregard based on incomplete 'evidence'.

If we use linear interpolation and a storage temperature 21 deg, from the paper we 'could' inaccurately estimate the nylon in the gear will have lost about 11% of its strength by being 15 years old. That doesn't sound too bad but only the OP will know how they feel about that on the sharp end and other factors will further weaken it with use. There are some other materials used as well (the stitching for one and possibly dyneema). What we have to ask ourselves is at what point is aging alone a reason to retire the gear? Remember slings may also be knotted etc and used on multipitch belays.

Another thing to consider here is if the OP gets back in to climbing and starts replacing some items, they may loose track of which items are older and newer. With climbing kit in constant use this is less of an issue as items normally wear out before age is much of an issue. With 15 year old kit in 10 yrs time some of that will be 25 years old!

The evidence we have ( or more accurately the lack of it ) is that no piece of gear has ever failed purely due to old age. In terms of risks that we should worry about while climbing, this is so far down the list that if you're worrying about it you need to get a sense of proportion. There are almost certainly greater risks that you should be focusing your attention on before you consider retiring an unused 15 year old sling.

I think that's a fallacy as retiring a sling doesn't take much attention, just cutting it and throwing it in the bin.  Similarly restringing my hexes with cord took all of 10 minutes.

It still took more than zero though. And you had to pay for the new slings and cord. But also, I assume you were replacing worn gear? I'm not criticising this at all. Soft gear wears out and should definitely be replaced regularly. What I'm saying is pointless is replacing unused gear purely because it's reached a certain age.

The 'how not 2' (do they still have 'highline' on the end of that) youtube channel has done a lot of cool videos looking into this kind of thing using a test rig. Really worth a watch and helps you make an informed decision. it actually made me feel a lot better about climbing on older gear. But as others have said, trad is a bit of a head game, but also you want it to be enjoyable, so personally if it was stressing me out I'd replace it 

- That statement to me in nonsensical as by using gear then it can not fail only due to age. Age must have played a part in most soft gear failures (ie no two failures are the same and given age does weaken nylon it must have failed differently). How many would not have failed with newer gear that has otherwise the same other factors we'll never know. Circumstantial 'evidence' is weak IMO.

You also said this "that age itself is not an issue", that is the main point I disagree with. The best scientific evidence we have is contrary to this statement. As I pointed out how much this is an issue in the real world is open to debate.

Probably this is true and I agree with the sentiment, but it doesn't mean that the sling being weaker because its 15 years old should not factor in to your risk assessment, in 5 years time it will be worn and possibly 15% weaker than it would be new due to aging alone, it may need retiring sooner (from first use) than a new sling and it may fail right now when a new sling may not. That's your call and its not really something you can accurately assess IMO. I still climb on some soft gear that is older than 10 years old if that helps clarify my position.

I personally think you need to use some common sense here. Generally the visual look and feel of the soft gear is enough, but if a single factor is getting a bit unusual like age > 15-20 years until we have strong evidence to the contrary then that should be worth consideration along with other factors, as you are operating well outside manufacturers current guidelines.

Yep that's pretty much my thinking, you'll never really know how you feel about it / it stresses you out until you use it a bunch of times.

I've been watching how not 2's channel for a while now, some interesting stuff on there.

Absolutely, they were very well worn.  However I still think I'd lack confidence in gear well past its stated expiry, and so would happily spend the small sum and time to make it such that I would have confidence in it by replacing the fabric bits.

You could always send a couple of items in to How not to, so he can test them. They will probably test around rated strength (although the results will be too limited to properly extrapolate all the items are likely to test the similarly), it would be quite fun atleast.

So you're saying that a worn / damaged sling that's a year old could hold, while an equally worn / damaged 15 year old sling would fail? That's possible, but not relevant. If a sling is worn or damaged then you should replace it right now, regardless of its age. If it's not worn or damaged, then he small reduction in strength due to being old is not a problem.

So not really relevant to the discussion then

If people feel safer climbing on new gear then by all means they should update their gear regularly. If they feel safer climbing on blue slings as opposed to red ones than they should replace their red ones with blue ones. Whatever floats your boat. But when someone asks whether their perfectly safe gear should be replaced, I like to look at the evidence, not my feelings.

It is.

The evidence is (unless you're testing gear yourself) the manufacturer's stated expiry date.  Which for fabric gear is usually ten years from manufacture regardless of usage.

Nobody claims the 10 year life is based on evidence. It's an arbitrary figure chosen because they had to put something.

The evidence I was referring to is that there is no evidence of gear failure purely due to old age.

But, I should have given up on his thread a long time ago, so I'm going away now. We can do all the same old arguments again next time this comes up.

Absolutely did not say that. Would and could are different. My point was relevant to the circumstantial 'evidence' you are relying on.

Yup

How old is the question, its a sliding scale. Your statement is of course factually incorrect as the paper above estimates at 70 years old nylon 6.6 will have lost 50% of its strength stored at 21 C, that is a problem. Its a sliding scale and age is a factor to consider not to completely disregard. If you are regularly climbing on the gear its unlikely to factor highly but when gear is comparatively old on first use it probably should be factored in during the usage of the gear. 

A large majority of old slings appear to have remained very strong, but do they always? It's a question worth asking, because if we're routinely trusting old textiles we want the answer to be yes, 100%.

I recently replaced two in situ threads on a route, tied in fairly wide nylon tape. The nylon was brittle, and both threads broke in my hand with a hard pull. They had been there for 20+ years, probably, and while it's impossible to say exactly what has happened to them over that length of time, it appears that the material itself had weakened over time, rather than abraded.

I wouldn't pronounce of the safety of other people's gear on the basis of that one anecdote, but it certainly gave me pause!

FWIW one place I would not expect to get a definitive overall answer is on a UKC forum. I would expect to get a wide spread of different opinions, and probably get some entertainment from an argument or two, but at the end of it not be any closer to deciding when to retire old gear

The simple answer to that is that they've been fried by 20 years of sunlight. 

I'm going assume Hooo is talking about gear stored in the dark.

At constant temperature?

At constant humidity?

Yes of course - I just said it gave me pause. If a sling can be that weakened outdoors, how much can a little bit of light weaken it? How completely dark is the storage required in order to avoid any degradation?

If I understood it correctly the article linked above ( https://www.sciencedirect.com/science/article/abs/pii/S0141391010002636 ) does suggest that nylon degrades just due to expose to air (via oxygen) at room temperature, albeit slowly enough that when gear is regularly used from manufacture its going to wear out before it becomes a major factor.

That study (and several before it) is not looking at how much nylon degrades but at how they can accelerate aging to predict the lifespan,

Nylon 6.6 has only existed for maybe 80 years so not a lot of OG stuff there to pull test and check, so they are doing all these studies to work out a way of knowing just how much nylon degrades without having to wait another 20 years so they can test pull some stuff.

"If" their method is correct, they predict it would lose 50% in 70 years. Military studies have found that used parachuting materials still retain >80% tensile strenght after 50 years, having seen the standard military service life of 12.5 years in use, so it's a big 'if'.

Since talking about parachute materials,  worth pointing out for comparison, that there is no lifespan given for parachuting equipment (almost exclusively done with nylon 6 or 6.6), where a 10 year old piece of gear is deemed practically new, 20 year old stuff is widely used, and 30+ years old harnesses and parachutes are regulrly used and commonplace.

There is a major manufacturer that produces reserve parachtutes (perhaps the most critical piece of equipment and also the most fragile) that certifies the parachute for a given number of uses/repacks, (typically lasting 20/25 years) after which they advise it has to be sent back to them for testing, and if it passes the test, re-certification.

With examples that have been well taken care of, often the reserve parachutes check out as if having have barely left the factory and get re-certified for another full cycle, so 20/25 years. That's a 50 year potential service life certified by the most stringent organization when it comes to safety, for the one thing you really don't want to fail and which is made with a nylon fabric thinner than a silver Rizla

A quickdraw that been 10 years in a drawer?  That's brand spanking new that

P.s. Not arguing with personal choices or attitudes though. You do whatever you gotta do to make you feel safe when you are runout above a single piece of gear. If that means retiring gear that is 10 years old, 5, or whatever then your choice will always be the right choice

Nice reply. Yeah I had noticed the study was extrapolating. They do however mention:

"The 21 °C predictions are shown to be reasonably consistent with long-term (up to 38 year) ambient results on similar Nylon materials removed from field-aged parachutes. Although the estimated average exposure temperature varies from parachute to parachute, the highest average temperature is estimated to be on the order of 21 °C."

Which seems to be contrary to what you are saying ("Military studies have found that used parachuting materials still retain >80% tensile strenght after 50 years"), who is right?  Do you have a source for that information?

Can't access this paper besides the preview, so can only speculate without looking at the data/methods. (The one that lead up to this is available if you are curious what it's about . Massive link so https://shorturl.at/DnNBk )

That short sentence includes:

"predictions"

"reasonably consistent"

"similar nylon materials"

"estimated"

"estimated"

So those words carry some heavy lifting.

Not an issue overall, as the data acquisition doesn't necesarily need to be particuarly nuanced as to its accuracy, since the data is only used for validating their method of predicting, and they are happy at this stage with it being 'reasonably consistent'.

'Reasonably consistent' could be that the curves/graph trends sort of match, rather than the actual numbers for example

That data is not colated to actually quantify the degradation of the pull tested materials as that would entail for the materials to be the same, rather than 'similar, account for the variables in condition, exposure during use, amount of use, material fatigue, color even, etc. Also it'd require to pull test the material as 'built' rather than just individual yarns which, depending where they sit in the webbing/tape, might receive more or less damage from environmental or in-use factors.

Or i might be wrong, haha. Can't really say much without reading it

I'm going to have a look at my history or have a good google see if i can find it. They were a set of studies from the 1990s that were scans from typewriter type studies from the us military, so not the easiest thing to find on a google. Been several years since i was researching parachute materials/construction.