Climbing Rope Frequently Asked Questions

Q: Can two single ropes be used as twins?

A: Single ropes are built and certified to be used individually, and are larger diameter—typically 9.5 to 11mm—and heavier than 7.5 to 8.5mm twin ropes, which must used as a pair, both always clipped through every piece of protection. Never use a twin rope as a single rope—one strand of a twin rope is too weak to trust as your only lifeline. Also, do not confuse “twin” ropes with “half” ropes, which are 8 to 9mm, and intended to be used together, but clipped alternately through protection. Some single ropes are certified for use as double ropes. Check the tag.

Q: How do I keep my rope from kinking? Whenever I coil it, I get a mess. Should I use a rope bag?

A: A new rope is naturally kinky, due to its stiffness and factory coil. The more you use a rope, the less apt it will be to kink. To work kinks out of a rope, uncoil it and run the full length through your hands several times. To prevent introducing kinks into the rope, don’t use the traditional coiling methods of spooling the rope around your feet and knees, or over your shoulder or head. These techniques twist the rope, introducing kinks. Instead, use the “pack-coil,” which is less apt to kink the rope. Better still, use a rope bag or bucket, which doesn’t twist the rope at all. When you belay or rappel, avoid the Munter hitch and figure-8 devices. Both twist the rope as it passes through them, introducing kinks. Standard tube-style belay devices let the rope go straight in and straight out. Much better.

Q: My rope got dirty and the middle-mark disappeared. The cord is only a season old. Do I scrap it? Or, is there a safe way to clean it and remark the center point?

A: Even the most sanitarily challenged person can wash a rope, but proceed with caution: Wash your rope the wrong way and you can destroy it. Do not put your rope in a washing machine. One of these Maytag units will spin it into a bird nest that is impossible for even a Mensa to unravel, and the machine’s agitator can damage the rope, or what’s left of it after the residual chemicals in the machine, such as bleach and detergent, have had their way with it.

To properly wash a rope, draw a nice warm bath and flake the cord into this. Let it soak for an hour or so, then add a mild soap such as Ivory or Nikwax Down Wash. Do not wash your rope with any soap noted as a “detergent.” Swish the rope around. Drain the bath and repeat until the water is clear. Finish up with a plain-water soaking and rinse, and set the pile of rope in a shady corner to dry for several days.

According to the UIAA, which tested markers on ropes, certain types of markers can cause up to a 50 percent decrease in rope strength. Err on the side of caution and do not mark the middle yourself.

Q: My rope was exposed to a car battery. Is it ruined?

A. Yes. There have been reports of climbing ropes breaking after being exposed to car batteries. In fact, simply storing your rope in a place that once had a car battery is cause for concern. Sulfuric-acid residue and even its vapors will damage nylon, even though the nylon can look fine to the human eye. In cases of severe contamination, the acid can glaze the nylon, but don’t use that as any sort of guideline.

Q: Should I invest in a dry-treated rope if I don’t ice climb?

A: Very few climbers actually need a dry-treated rope because of soggy route conditions, but even fair-weather climbers will want a treated rope because the treatment reduces friction, which reduces wear and rope drag. And the same treatment that repels water also repels dirt, increasing rope longevity.

Non-treated ropes may be cheaper and easier to grip because they aren’t as slippery, but they will feel stiff and be more prone to kinking. You can apply an after-market rope treatment, which you can also use to refresh a worn, dry-treated rope. Check out Sterling’s Pro-Arid dry treatment— a 12-ounce bottle ($28.50) will treat four ropes.

Q: I spilled RV antifreeze on my rope, is it ruined?

A: The active ingredient in RV antifreeze is food-grade propylene glycol, a non-toxic, oily liquid with a wide range of applications from food additive to personal lubricant. Antifreeze also has water, and might contain ethyl or “grain” alcohol.

According to the Honeywell Corporation, once a large supplier of the nylon 6 used in ropes, nylon is not greatly affected by motor oil, mineral oil, salt water, Freon, gasoline, kerosene, benzene, chloroform, paints, pine oils or insect repellents with DEET. Bleach and sulfuric (car battery) acid are the big nylon killers. RV antifreeze wasn’t tested, but to paraphrase Scott Newell of BlueWater ropes, anything you can put on your skin shouldn’t damage a climbing rope.

Q: A dog peed on my rope. Should I throw it away?

A: Nobody knows for sure. The chemical make-up and strength of dog urine varies. There is some evidence that cat pee can weaken a rope. Kolin Powick of Black Diamond tested a rope that had been squirted by Felix, then washed twice with baking soda. In pull tests, the pee rope broke at 95 percent the strength of a brand new rope of the same 9.2mm diameter and model. Keep in mind that the contaminated rope was used and had been washed twice. Also worth noting is that manufacturing and the testing process itself introduces inconsistencies—a five percent strength difference is within a reasonable margin of error.

The jury is still out on urine contamination. More testing needs to be done. Likely, urine does cause damage at some level, but the extent is probably minor: Lots of ropes get peed on and none have been know to ever break. But, if in doubt, throw it out.