QC LAB: OLD VS. NEW GEAR TESTING

Remember that weathered tree tat you were eyeing? Or how ‘bout that 20-year-old rope you found sitting in a basement completely unused? Rest assured. KP and the QC Lab crew head to the testing room to answer your age-old question … how strong is it?

In this QC Lab, we’ll look at four different customer product questions:

A sun faded harness from a display window at a retail store. Does the sun affect the strength of a harness?
An un-used properly stored rope that is over 20 years old. Can I still climb on this cord, or should I pony up and buy a new one?
Some slings that my buddy had on his rack and thought were looking a bit sketchy. Just because they’re ratty, should I continue using them or get some replacements?
Some webbing and cordelette that a climber was anchored to at a belay that kind of freaked him out. Four climbers at a tree belay clipped to some webbing and cordelette. Any reason for concern?

Disclaimer: As always, this is not intended to be definitive. Instead, this is some quick and dirty testing and data to help shed light on the questions and make people think. We’re basically using one data point of the suspect product, and one data point of a new comparative product. So there really is no need to inundate BD with emails and comments about the fact that this is incomprehensive and not statistically relevant—because we’re aware.

Note: For reference, some folks like thinking in Kilonewtons, some like pounds – so we reference both. 1kN = 224.8 lbf.

A retail store put a brand new Black Diamond Momentum harness in their display window. After several months, they were swapping out their product and noticed that the red harness had faded. They were wondering if they should discount the harness but still sell it, or throw it away. Does the sun fading the outside of the harness affect the strength and/or performance?

With only one data point on each test, it’s not really relevant to say one is stronger than the other. However, the sun-faded harness passed the proof test and all component tests. The reality is that all values shown are basically within the range of what we would see for a new harness. That’s not to say that sun fading can’t affect strength. It most certainly can as can be seen in some previous QC lab articles. What’s important here is to realize that the construction of the harness can make a difference. This particular harness has structural webbing that is covered by a comfortable padded shell. The most visibly faded part of the harness was the padded shell (the red part), which actually doesn’t provide any strength.

If this were a different harness, or perhaps rotated in a different orientation so more of the structural webbing (waist belt for example) was exposed to the sun, then it is possible that we could see a reduction in ultimate strength.

So, though in this case, the sun didn’t appear to really affect the strength of the harness, make no doubt that sun can definitely fade structural webbing to a point where you see a reduction in strength. If your life-dependent gear is getting sun-faded, it’s usually best to be conservative and retire and replace.

20-YEAR-OLD UNUSED ROPE

A gentleman emailed me a while ago after finding a ‘brand new OLD’ rope in his basement. It had been stored correctly (cool, dry place). It had never been used and he asked if it would behave like a new one.

Several years ago, a longtime BD employee had the same question. He had a brand new 20-year-old rope—so he brought it in and we tested it. At that time we compared it to a similar diameter rope in ultimate strength, and found that it basically was as if it was new. We decided to do the same with this rope.

We measured the diameter to be a solid old-school 10.5mm and had to do some digging to find something brand new around the office of a similar diameter. I actually couldn’t find anything in the beefcake 10.5mm, but did track down our next-year’s new Black Diamond 10.2mm cord. This time we did three very quick and dirty tests:

—Ultimate Tensile Strength – just tying figure 8 knots in each end (because it’s faster)
—Ultimate Tensile Strength – using single-strand test fixtures (this removes the knot from the equation)
—Peak Force with Factor 1 Fall (pre-loaded figure 8 knots with the 80kg mass, three Factor 1 falls in a row without letting the rope relax, or loosening knots, etc.)

Once again, with pretty much only one data point in each test, it would appear that the 20-year-old new rope performs pretty much as if it was made yesterday. These were the same results I had a few years ago when testing an old, but unused rope that had been stored properly.

The old, unused rope pretty much mirrored the results of the new rope:

Ultimate strength using figure 8s, or single strand test jigs were incredibly similar.
The figure 8 knots weakened the rope by a similar percentage in both cases (typically knots can weaken the single strand ultimate strength value anywhere between 20-30%).
The FF1 drop test impact force was very similar in both cases and increased similarly with each drop – as is typical with repeated drops on the same section of rope without letting it relax.

It’s actually unbelievable how close the results were—but we do need to remember that we’re talking about only one data point, and we’re not comparing exact samples here—the old rope is 10.5mm, and the new one is 10.2mm from a different manufacturer with likely different construction. It’s important to think of this information as directional—to give some insight.

In the process of rope production, the fibres are mechanically doubled, twisted and braided in several stages. In this way the fibres finally attain a condition of mechanically induced stress. A long-term storage leads to retardation and relaxation. This means that stress in macromolecules is “relieving”. This phenomenon is not harmful, on the contrary it is connected with an improvement of dynamic properties. Research works showed that the results of tests of dynamic performance of ropes that had been (optimally) stored for several years were often better than values measured immediately after production. Polyamide also does not contain additives and softeners like, for example, PVC that could diffuse out. This is the reason why no embrittlement occurs.

So should you go climbing on an old, but un-used piece of gear? Well, ultimately it’s up to you. Chances are technology has changed and there is better gear on the market. In this case, this rope is considered super fat by modern standards and most folks wouldn’t be psyched to carry a big old cord like that to the crag, much less have a belay device that worked properly with it. Plus, as we all know, climbing is a serious game, so if you’re ever in doubt about your rope, or any piece of gear—it’s probably best to retire it.

My buddy’s rack is embarrassing. I went out to climb the Diamond with him several years ago and couldn’t believe the cobbled together mess that he called a rack. Over the years since then he’s slowly built it up to be something reasonable. However, the last time we climbed together he pulled it out and now was starting to get sketched out by the state of his slings. I replaced his slings with new ones and told him we’d test them so that he can see if his fears were valid.