bicycle tube rubber: risk of weakening nylon?

Rope-end retainers made from a bicycle tube.

Chemists/engineers: Do you think that I should be concerned about chemicals leaching out of the rubber from a garden variety bicycle tube into my dyneema slings? [I did wash the tube segments well with hot water and soap, and (of course) the tube never had Slime or any other self-healing tube glue in it]

Thoughts?
-gg

I know the standard answer:
'Yer gonna' die!'

Not a chemist or engineer, but I did the same thing a few years ago and I'm still here. That said, I have replaced most of those skinny draws - I like the fatter ones as they flip around less and are better for yarding on!

The sling on the table looks like open webbing?

http://www.petzl.com/us/node/9886

I see no problem using a bike tube. It would be wise to clean them first though. The sling on the table is open webbing.

newriverclimbing.net/images…

www.petzl.com/us/node/9886

Tom Lekan wrote:The sling on the table looks like open webbing? petzl.com/us/node/9886

What do they mean by "STRING"?

Tom Lekan wrote:The sling on the table looks like open webbing? petzl.com/us/node/9886

What do they mean by "STRING"?

Matt Hasenohr wrote: What do they mean by "STRING"?

"STRING" is name that petzl gives that piece of rubber at the ends of a dogbone.

The New River one explains what the risk is, but if you are assembling these draws yourself and double/triple checking that the rubber is only holding the sling, and the sling IS in fact around the carabiner itself, then you have nothing to worry about.

The Petzl String covers up the sling with a piece of rubber whereas the tube segments frame the business part of the sling for convenient frequent visual inspection.

AMAZING IDEA! It may prove wise to check the sling under the rubber every 6 months or so. Something I am going to do now with my petzl rubbers.

Brendan Blanchard wrote:...then you have nothing to worry about.

Forestvonsinkafinger wrote:AMAZING IDEA!

I think you misunderstand the risk.

Any open sling (i.e., one that is a loop, and is not sewn such that there are independent loops at either end) is at risk for the failure described, whether or not you assemble it with a keeper yourself.

All it takes is for one strand of the loop to slip through the gate unnoticed and all that stands between you and oblivion is a piece of rubber.

Perin Blanchard wrote: I think you misunderstand the risk. Any open sling (i.e., one that is a loop, and is not sewn such that there are independent loops at either end) is at risk for the failure described, whether or not you assemble it with a keeper yourself. All it takes is for one strand of the loop to slip through the gate unnoticed and all that stands between you and oblivion is a piece of rubber.

True. Care must be taken when lengthening the draw. If you always shorten the draw by running the retainer-bound 'biner through the loose one it doesn't create a tangle when you lengthen it (assuming you clip the gear end of the draw first, then un-clip all the unbound strands with the rope end 'biner.)
Putting the bar tack at the retainer makes the strand layout more obvious.
If you lengthen the draw from the gear end 'biner it is possible to make a mess.

Gregger Man wrote:'Yer gonna' die!'

Bingo.

What's the blue you use to mark your 'biners?

Are you doing this to dog bones or slings? Looks like both based on the photo. I see the point in putting this on your draws but I wouldn't want this on my slings as it would make extending them a pain in the ass and just one more thing to worry about when I'm gripped and ready to take a dive.

As to your question about hurting the dyneema or nylon or whatever...I'm not an engineer or a chemist or very smart for that matter but I've seen anchor slings threaded through a bike tire to help protect them from the elements. Rapped off rigs like this several times. I'm not dead yet.

And yes...yer gunna die.

scott,
Hobby Lobby paint marker.

Yarp wrote:Are you doing this to dog bones or slings? Looks like both based on the photo. [...] it would make extending them a pain in the ass [...] And yes...yer gunna die.

-Both slings in the photo are the same, but I'm holding the one in the foreground by the bar tack.
-Interestingly, my partner said yesterday that he found it actually makes it easier to extend. If the draws are shortened the same way by the second, everything is cool. If the second were to double up the draws without caring which 'biner went through which... then you're right: you could get a fustercluck when you go to extend any draw.
-Yup.

Thats a good idea.
Wouldn't dog bones made of rubber be cool too?

Mike Lane wrote:Thats a good idea. Wouldn't dog bones made of rubber be cool too?

-Both slings in the photo are the same, but I'm holding the one in the foreground by the bar tack. -Interestingly, my partner said yesterday that he found it actually makes it easier to extend. If the draws are shortened the same way by the second, everything is cool. If the second were to double up the draws without caring which 'biner went through which... then you're right: you could get a fustercluck when you go to extend any draw. -Yup.

First, if they're both OPEN slings, and here they look like 12in open ones, there is a hazard with using "strings" on them, as others have mentioned.

The best explanation of this can be found HERE

Frankly, I would say DON'T use the "Strings" on open slings period.

Next, I'd say you're inviting MORE problems by shortening those already short open slings. Clipping biner to biner or what ever is just ASKING for the issues cited above to occur.

12in OPEN slings are the same as 3' slings IMO. A weird length that ALWAYS feel awkward to use and/or stow. It's worth just getting a long dogbone if you like that size. OR go with a tripled trad draw and ditch the "String"

BUT to answer your original question, no I doubt the washed inner tube will have any effect on your slings.

Chemical Compatiblility

Informed opinion from a Prof. of Organic Chemistry:
Probably not an issue chemically, however, all of these types of devices increase the amount of wear at the carabiner-webbing interface. Replace your draws every 7-10 years and you'll be OK.

I put the open sling risk in the same category as threading a rappel device with the wrong strands - it is possible, and the optical illusion can fool you. It's something else for which you have to develop a double-check habit.
A simple solution for those of us that plan to use a retainer on open slings anyway: trap an extra loop around the 'biner inside the rubber retainer. It's not going to weaken the sling the way that a clove hitch would, and for you to accidentally un-do the connection lightning would have to strike twice.
Thoughts?

Added loop to avoid 'hidden un-clipping'