11

Sometimes it is necessary to cut a climbing rope, either to shorten it or to trim worn ends.

If were one to cut a climbing rope, how would one do so?

28

If you don't have an electric hot-knife, it's possible to heat a (sacrificial) table knife in a flame until it glows, and use that to make the cut against a wooden block. It doesn't need to be sharp, just hot.

I find that I normally need two cuts (with the knife heated until glowing slightly red each time) to chop and seal 11mm static rope.

Keep the knife in your gear maintenance set for next time, as the heating will make it unappealing for table use afterwards.

  • 2
    This is what I do, being obviously the easiest (and cheapest) way. The final result bears no difference to using an electric knife. If you heat the knife until it starts glowing slightly red, it will cut the rope through without the need to re-heat it. Another possibility is using a normal room temperature knife and, later, sliding the sheath over the core just a tiny bit and sealing it with a lighter - this minimizes the chance of the end getting stuck. – QuantumBrick May 22 at 14:34
  • This works, but if you have to do a bunch, a rope cutter is a lot easier – Charlie Brumbaugh May 22 at 14:35
  • 1
    Agree, like if you work in a climbing shop. Most people only need to cut a single rope at a time though, and cutting it is already sad enough. – QuantumBrick May 22 at 14:37
  • 1
    @Quantum, I forgot to mention how hot is "enough", so I borrowed your words for my edit (perhaps climbing rope takes slightly less to cut than static rope? I guess it also depends on the heat capacity of the blade, too - a thinner blade needs more cuts). – Toby Speight May 22 at 15:33
  • 1
    @Ælis, I normally use a cooker ring until the knife glows red. That's usually enough (sometimes it's enough for a rough job with just one cut, but even then I normally end up re-heating to tidy the edges). – Toby Speight May 23 at 18:36
11

The easiest way to do this is to use an electric rope cutter.

enter image description here

Source

To use this you wait till the blade is hot then stretch the rope tight with your hands giving yourself a couple of inches on either side of where you want to cut and bring it down across the blade. The blade will go through the rope like a hot knife through butter and seal the ends at the same time. Here is a video of someone cutting webbing with one.

This also works for paracord, accessory cord, and webbing.

Then what we would do is write down the date it was cut and the length on a piece of paper and place the paper on the end underneath a piece of clear shrink tubing before shrinking the tubing with a heat source to finish it off.

It's also possible to do it with a sharp knife and a lighter to seal the ends, but the rope cutter is the easiest way to do it.

  • Also known (at least in the UK) as a "hot knife", and available in hand-held form. I usually write the start of service date on the label, rather than the date of the cut, along with the length and a distinguishing letter (eg. "25B 2018" - if I cut that down I might end up with "10C 2018" and "15A 2018"), printed on plastic rather than paper tape. – Toby Speight May 22 at 10:10
  • 5
    If you only cut a rope every now and then, cutting with a normal knife and sealing with a lighter (or a camping cooker) is definitely sufficient – Manziel May 22 at 10:51
  • Man, I burned myself on this machine so many times... oh memories. – Gabriel C. May 22 at 16:49
  • 1
    @CharlieBrumbaugh Yeah most of the burns were from finger-shaping the rope ends. It didn't help though that for some time the store had the fastek buckle trays just to the side. Just brushing your arm on the blade would cook the skin good. – Gabriel C. May 22 at 18:13
  • 1
    As a knot tyer I tend to tape multi layered rope temporary before cutting. Is that not needed for a climbing rope? – Willeke May 22 at 19:04
6

Just a reasonably sharp knife and a tape are fine. First use a sticky tape (better cotton, rather than electric - the climbing tape for finger taping is fine) around the place of the cut. Then cut through the tape and use heat of a small gas flame or outdoors even just a lighter to connect the threads by melting to prevent fraying. The tape can remain there and can be used for marking. The tape prevents any initial fraying before the melting.

5

If you don't have a hot knife or professional rope trimmer/cutter, you can use a very sharp (fresh) single-edge razor blade. Make the cut and then seal the end of the rope with an open flame or a flame from a butane-fueled "jet lighter." If done slowly and patiently you'll be able to gently fuse the kern to the mantle and the end should look nice and fairly transparent until it cools. Any heat-fused rope-end in regular use will eventually get flexed enough to crack. Having done this numerous times, I have not had any problems with additional fraying or separating of the kern.

  • As a reliable means to prevent rope ends to fray, it's possible to use heat shrink tubing of an appropriate size. It's permanent and sturdy. – Gabriel C. May 22 at 19:33
  • 1
    We have had good success with lopping it with a good pair of cutters and then applying the gas stove to the keep end to reseal the end. – Joshua May 22 at 20:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.