UHMW tubing for cambium saver?

setting the lightweight thread aside for a minute here is an interesting application for UHMW tubing (UltraHighMolecularWieght).

at a industrial plant i used to work at, they had UHMW tubes on some of the equipment, to reduce friction on high speed moving (SLIDING) parts. Because UHMW plastic is "self lubricating", highly abrasion resistant, and flexible, it got me thinking: why not use it for a very friction free cambium saver?, (like the leather cambium tubes that Sherrill sells)........CMI already uses UHMW polyethelyne sheets with grooves milled into it for friction free edge protection, http://www.rescueresponse.com/store/cmcultraedgepads.html

....seems it would also be suitable (in TUBE form) for us treeclimbers find a tube of the stuff and thread our ropes thru....... a 2 - 3' long piece, molded into a upside down "U" shape and left on the rope.


Teflon PTFE tubing would also be a suitable candidate, it has a much higher melting point.......

comments?

something like this, maybe shorter, or use it as an insert in flexible conduit sleeves....i did find a piece that is flared at both ends..

sounds very interesting.
where can you get the tubing from?

I tried this and here's what I found:

First the reason. Repeatedly pulling up climbing ropes over the same limbs in our favorite climbing trees can cut a groove in the tree. I think we all want to avoid that.

I went to ACE Hardware and bought some 3/8" ID polyethelene tubing (Slickline won't feed through a smaller ID). Vinyl tubing is too sticky and flexible; the poly tubing is harder and slicker.

I use Slickline and it can be pushed through the 3/8" ID poly tubing if you take the overhand end knot out. A safety knot will not pass through it.

The poly tubing comes on a reel and hence it acquires a curved form that's just about perfect as a cambium saver.

I installed the tubing over a limb and just trying to pull the Slickline through it pulled the tubing off the limb. So I wound one layer of friction tape over most of the length of the tubing and tried it again and it worked perfectly. Well, the tubing vibrated as the Slickline passed through, but I believe if I cut the tubing length back from 24 inches to 18 inches it will smooth out.

I used this method yesterday in a climb. The tubing is cheap - about $.45 a foot. I had to pay about $3.50 for a big roll of friction tape.

Next one I make, I'm gonna just put one layer of friction tape lengthwise on the inside curve of the tubing and a piece around the tubing at each end and maybe in the middle.

Hi Ron, glad to hear this is being tried! do you have anymore feedback for us? specifically, i'm looking for how the tubing lasts after an ascent and descent with full body weight on the rope. I know with teflon and UHMW that it handles heat extremely well, but have'nt eperimented with just Polyethelene tubing.

SRT,

Sorry, I was on a different track. I was talking about using the tubing to prevent the throw lines from burning or cutting a groove in a tree from repeatedly hauling up a climbing rope over a favorite practice limb.

But I did try a large size of the vinyl tubing with my ArborPlex climbing rope as an interim tree saver until my leather cambium savers arrived. The vinyl tubing is too flexible. It colapses on the rope and it's not slick enough inside the tubing so when the load is applied the rope pulls tubing off of the limb. Also there were signs of scarring or abrasion inside the tubing, so it wasn't holding up well.

I haven't tried the poly tubing with climbing rope, but if you could find poly tubing large enough, ie about 5/8" - 3/4"ID, I think you'd find that the rope would pull the tubing off the limb.

But a leather Cambium Saver has worked really well for me and as I recall don't they cost about $10? Of course one down side of leather is water. They probably wouldn't work so well in rain.

Now I'm curious. I guess I'll stop by ACE on the way home and pick up some 3/4" ID poly tubing, if they have it, and give it a try. If it works, it'd sure be a good all weather tree saver.

^ i'm going to web order some of the Teflon tubing, maybe find some cut off pieces for cheap.

for my cambuim saver i use a 5' RSI 1" eye/eye sling, with stainless steel shackles (sling rated for two person loads 8500lbs WL, shackles rated for 3500 lbs WL each)

got a leather one, its rapidly wearing out from moisture....

i wanted ot try the Teflon tubing on my minimalist treeclimbing kit, to eliminate the wieght of the bigger setup descibed above.

let me know how that tubing works if you find it in larger ID.

Cheers

I just called ACE; looks like the largest they carry is 1/2" ID, so it may be hard to find 3/4" ID locally.

I made a couple of AL rings and used 1" tubular webbing to make a sling for a tree saver. I machined the rings, large is 2.5" ID, small is about 1.5" ID out of 6061 AL. The different sizes allows an easy pull down recovery of the sling and rope.

I've brought a set of them to school, so as soon as the tensile machine is back up, I'll test their strength.

But I find the rings and webbing a bit cumbersome to use. You have to think much more about how to install them (from the ground) and the webbing can get twisted which is bound to affect strength and it can cause the rope to feed through incorrectly.

Ron, I'd love to hear the results from the break test.

Sounds like you need stiffer webbing. You (I) can sew a stiffener into it. Do you have a sewing machine?

love
nick

Nick,

I suppose flat webbing (as opposed to tubular) would be a little stiffer. It would increase the sling (webbing) from 8000# to 12,000# but it can still twist and turn.

I suppose one could get webbing thick and stiff enough to resist twisting more but when you pull rings connected via webbing through limbs and crotches it doesn't always go smoothly. Plus it's much more trouble to install a sling than a tube.

I let you know when we run the tensile tests. I think we're waiting on a technian to get the tensile machine up and running again.

I also have a set of AL rings that I bought from Wesspur and I'm gonna test them also.

I'll let you know.

Originally posted by SRT-Tech
^ i'm going to web order some of the Teflon tubing, maybe find some cut off pieces for cheap.

for my cambuim saver i use a 5' RSI 1" eye/eye sling, with stainless steel shackles (sling rated for two person loads 8500lbs WL, shackles rated for 3500 lbs WL each)

got a leather one, its rapidly wearing out from moisture....

i wanted ot try the Teflon tubing on my minimalist treeclimbing kit, to eliminate the wieght of the bigger setup descibed above.

let me know how that tubing works if you find it in larger ID.

Cheers

SRT,

After thinking about the Teflon tubing, I think you'll have the same problem I did. That is, there's more friction between the rope and inside of the tubing than between the outside of the tubing and the tree. That means the rope will pull the tubing out of the tree.

I wonder if tape will stick to Teflon tubing well enough/long enough to hold the tubing in place in the tree.

This has been my experience with plastic tubes or hose, the rope grabs on the inside and pulls it off the branch.

Check out the Su Sleeve on New Tribe's site, I think it represents the state of the art in lightness, compactness and flexibility in a pipe/hose style cambium saver. I've been climbing on one and it's very good.
-moss

looks like someone already had this idea

http://www.rei.com/product/47865665.htm

Originally posted by SRT-Tech
looks like someone already had this idea

http://www.rei.com/product/47865665.htm

It's not clear to me from the product description whether that will work for dynamic rope use (DdRT). It looks like static rope protection.
-moss

That product will not work for a running rope. You can't use it for DRT. I got a piece of that from Yale a couple years ago. One of their sales guys handed it to me and said, "here, figure out what we can use this for." In two years, I haven't found a good use for it, though it is neat.

It is good for a fixed line that might be being chafed by something else. Imagine a fixed line that leans up against a tree or telephone pole maybe.

love
nick