Like many of you, I heard you shouldn’t wash caving rope with a pressure washer because dirt could be forced into the core and abrade the fibers. Bruce Smith at On Rope 1 says this is a myth and challenges us to try it.
I accept. I pulled out an ODR (old, dirty rope)—PMI Max-Wear circa 1992. This rope has seen lots of mud and occasional cleanings. It was last used two weeks before testing.
This rope had a damaged spot (more on that later), so, I cut out a little extra for this test.
The 6′ sample rope has been divided into three sections. One section I will clean with a conventional rope washer, with brush bristles inside. Another section will be cleaned with the pressure washer. The last section will not be cleaned—a control, if you will.
This is the pressure washer I used. It’s a residential grade Karcher that spews 1500 psi.
I ended up getting the sprayer a lot closer to the rope than this pic shows. Actually, I put the sprayer right on the rope. I even tried to cut the rope with the spray. I was unable to do any noticeable damage. Disappointing. I wanted to cut with water. So, I grabbed some webbing and some parachute cord (aka, p-cord, 550 cord). No noticeable damage with them either.
But, where did the dirt go? Did the pressure washer push the dirt into the rope fibers and core?
Time for some surgery. I cut open all three sections to expose the core and the inside of the sheath.
None of the samples showed any signs of dirt, mud, silt or any other foreign substance inside the rope. Nothing had made it past the sheath after the pressure washing or even after 17 years of caving. Pressure washing did not drive any dirt into the core of the rope. Of course, PMI caving rope has a tightly wound and thick sheath which undoubtedly helps keep dirt out. I should try this with some looser sheathed rope…
Pressure washing is a great way to get a rope really clean, but it is labor intensive. It took about twice as long to clean with the pressure washer compared to the brush washer.