Discussion Topic |
|
This thread has been locked |
Don Paul
Big Wall climber
Colombia, South America
|
|
Cosmic is right, its aluminum oxide not aluminum metal. Aluminum does oxidize (rust) but oxygen can't penetrate through Al oxide very well, so only a thin surface layer is affected, and like stainless steel, it doesn't "rust". Its possible that the alloying changes the bonding between the oxide layer and the metal underneath, but that would not be my first guess. It's also possible that different coatings on the rope would bond to aluminum oxide to a greater or lesser extent. Surface chemistry is not simple or easy to predict. However, I would think that one Al2O3 particle would be like any other and whatever alloys are in the metal should not be in the oxide.
I would just put the rope in the washing machine like some else suggested. I don't worry about ropes breaking unless the sheath is cut.
|
|
BrassNuts
Trad climber
Save your a_s, reach for the brass...
|
|
|
Topic Author's Reply - Feb 6, 2013 - 12:36pm PT
|
Some good input and discussion here. Pell & Don Paul - thanks for the tech talk, that's really helpful. I'm thinking that different biners and belay devices could be subject to more aluminum transfer depending on the hardness and durability of their respective anodized finishes, the radius/shape at the mechanical wear points as well as the base alloy composition.
So far it's looking like the best/most practical way to minimize BRS is to stick with teflon coated ropes, which seem to be a minority out there. I just wrote Bluewater asking if their 9.4 or 9.7mm ropes have a teflon coating as it's not clear from the product info on their website. It would be nice to have a reference list of teflon coated ropes to help folks in their search for a new cord...
|
|
Don Paul
Big Wall climber
Colombia, South America
|
|
I'd like to see a uv-resistant coating, particularly for webbing. Webbing gets seriously degraded - Jim Donini almost bought it a couple weeks ago by rapping off a UV-damaged sling that couldn't even hold body weight any more. That was a wake up call, as was the Euro guys who leave fixed biners, that wear in a way that gives them a sharp edge that then cuts the rope. These are serious safety concerns, but not ones that get much attention.
|
|
JimT
climber
Munich
|
|
The black is technically called "smut" and is the bane of the aluminium treatment industry and welders though you can remove it easily enough chemically. It´s a mixture of aluminium oxide, magnesium oxide and a few traces from the rest of the alloy. Aluminium oxide has various colours but it is fundamentally transparent (you can´t see it on the polished parts of the karabiner) BUT the particles are so small they work as a light trap and appears black. Nano technology strikes again!
|
|
Curt
climber
Gold Canyon, AZ
|
|
Cosmic is right, its aluminum oxide not aluminum metal. Aluminum does oxidize (rust) but oxygen can't penetrate through Al oxide very well, so only a thin surface layer is affected, and like stainless steel, it doesn't "rust".
I believe it's actually just the opposite--and the "black" results from the rope passing over aluminum metal--and not Al2O3. Dingus is correct that a brand new carabiner with a nice shiny anodic oxide still intact will not cause this problem. A new non-anodized biner, however, will--and the anodized carabiner will too, as soon as the anodic oxide is worn through.
Curt
|
|
pell
Trad climber
Sunnyvale
|
|
To be more precise: rope abrades aluminium. Thin layer of abraded aluminium oxidates and becomes black. It's possible after your binners protective layer is worn.
Thus we have another option mentioned earlier by Dingus Milktoast.
|
|
BrassNuts
Trad climber
Save your a_s, reach for the brass...
|
|
|
Topic Author's Reply - Feb 7, 2013 - 12:41pm PT
|
I contacted Bluewater to see if any of their ropes utilize a teflon coating as their website does not indicate this feature for any of their dynamic rope models. Here is the sales manager's reply:
"Thank you for contacting us. We played around with Teflon back in the early 90’s but it never caught on. We still use our proprietary dry treatment which we feel is the best on the market. I know that Tendon ropes is using Teflon now but I didn’t know about Mammut."
Interesting. To me, there doesn't seem to be a downside to using a teflon treatment for at least some rope models given the performance of the Mammut Infinity. I wonder if there is a way to apply a PTFE coating to a rope after purchase. Maybe a company like Nikwax might develop a product like that...
|
|
Tarbuster
climber
right here, right now
|
|
So I'm sitting in the dental chair for a 3 1/2 hour reconstructive process yesterday.
The dental tech starts hammering 11 of my teeth with a miniature sandblaster for the prep.
"Say sweetheart, what sort of abrasive does that thing sling?"
All perky and happy in her work she says:
aluminum oxide!
|
|
toyon
climber
|
|
New question for this old thread.
Coming at this problem from the other way, wondreing if anyone has had better luck managing black rope syndrome using different aluminum biners? For example the petzl attaché seems to wear like butter, compared to a standard BD offset D.
Yeah, I can switch to steel for certain set ups etc. But given 99% of our culture is anecdotal, I figure some of you have found an aluminum biner that less prone to wear than others.
Thx.
|
|
BrassNuts
Trad climber
Save your a_s, reach for the brass...
|
|
|
Topic Author's Reply - Nov 4, 2017 - 09:42am PT
|
I switched to a steel locker and belay device (Edelrid) and this all steel combo cuts down on BRS substantially. These puppies will likely outlast me and they stay pretty cool even after a long steep rap.
|
|
Steve Grossman
Trad climber
Seattle, WA
|
|
I use nothing but anodized draws and don't get the blackness nearly as fast even though that coating does wear through.
Wall climbers are very familiar with smut in all of its many-splendored manifestations.LOL
|
|
eeyonkee
Trad climber
Golden, CO
|
|
I just hope that I don't get the "black lung" from being around my blackish, aluminum-particle-infested, heavy-ass rope. It's bad enough just trying to pull it up when 150 feet out.
|
|
NegativeK
climber
Chicago
|
|
I grabbed a random MSDS to see if breathing or eating AlOx is bad news bears, and apparently it's (non-specifically) just an irritant. Don't eat BRS ropes, don't inhale BRS ropes, and don't rub them all over yourself..?
http://www.sciencelab.com/msds.php?msdsId=9922858
The most interesting part, though:
Solubility:
Very slightly soluble in cold water. Insoluble in hot water.
I wouldn't expect solubility to be relevant when washing it, but being more soluble in cold than in hot is just weird.
|
|
jeff constine
Trad climber
Ao Namao
|
|
Just go climb, forget about it. Ropes are cheap.
|
|
Steve Grossman
Trad climber
Seattle, WA
|
|
Fascinating sidelight sween. Aluminum oxide is nasty stuff.
I built a house for two architects, husband and wife, that featured a commercial aluminum railing system. They had a choice between mill finish and an anodized one and chose the mill finish despite my every warning about the inevitable black handprints on their white walls and health hazards to their kids that I felt were coming. Yet another sign off form for them.
|
|
skitch
Gym climber
Bend Or
|
|
Moving to Bishop and Climbing in the Gorge seemed to cause my ropes to turn black faster and much more so than from any other place I've lived/climbed. I just try to always have a pair of gloves in my pack for belaying, old mtn bike gloves work great, or cheap work gloves.
|
|
EdBannister
Mountain climber
13,000 feet
|
|
some ropes are more abrasive of carabiners and other aluminum surfaces they run over, that others..
yes it is all nylon, but construct varies.
compare mammut, edelweiss, or new england (maxim) group a. to blue water..
Group a sheath yarns have two different sheath yarn twists, left or right. a left twisted yarn is used, usually in pairs, to go to the right around the core. the result is the surface fibers are roughly parallel to the axis of the rope.. they abrade less, accumulate less aluminum oxide, and wear better because they are more smooth over a biner, especially under load.
Blue water sheath yarns have no twist, so fibers are more across the axis of the rope, and hence abrade and wear more quickly.. and if you want black hands, blue water is your cord!
|
|
dee ee
Mountain climber
Of THIS World (Planet Earth)
|
|
It seems like this phenomenon is worse than it used to be. 30-45 years ago ropes got dirty but not as black. I had Mammuts and Edelrids that never got as dark as my newish blue BD cord.
I can't attribute it to old gear since I have mostly newer biners.
We got a new BD rope in 2017 and it stained very quickly.
Maybe it is due to modern atmospheric conditions that amplify the gankiness (sp? LOL) of aluminum oxide?
|
|
|
SuperTopo on the Web
|
Let us know!