UKC

got silicone sealant on my ab rope last night whilst working on a friends roof can anyone tell me 100% that it wont do it any harm ?

In reply to peter fetlar: silicone is one of the most polluting chemicals because it is so stable it doesn't degrade nor affect anything else.

In reply to grumpybearpantsclimbinggoat:


It does however produce acetic acid as a by-product of the curing process. No idea what it does to rope (probably not much)... Sorry.

jk

In reply to peter fetlar:

Shouldn't worry too much about effects, be more worried about next time you ab on it, you could find it a little fast on the descent......

In reply to peter fetlar:

I'm not sure of the effect silicone will have on a rope but if your worried about it you could always isolate that part of your ab rope with an alpine butterly. You'll just have to pass the knot each time.

In reply to peter fetlar: It'll be fine, silicone is very flexible. If you'd used caulk that would be another matter...

In reply to jkarran:

Wikipedia says acetic acid can be used in nylon production to limit the length of the polymer chains, so it should be safe on existing nylon. It does cause metal to corrode more quickly though, so clean it off any metal gear.

In reply to timstyles:
No, acetic acid has a severe effect on nylon.

In reply to peter fetlar:
It least it's dry proofed now

In reply to timstyles:

I'm not convinced that is an accurate interpretation of the process. In your description, acetic acid is used to inhibit the formation of nylon polymers: this doesn't necessarily tell us if it is safe or not. I don't think strong acid is generally very good for an amine bond, but acetic acid isn't a strong acid...

In reply to peter fetlar: The silicone won't be a problem, but the acid will be, so give it a good wash and scrape off what sealant you can.

In reply to peter fetlar:

If there's one voice on this thread I'd listen to it would be that of Jim Titt. I recall reading a report on a chap who decked indoors after a rope snapped - the conclusion was acid contamination from an unknown source (possibly battery acid after the rope was just put down in a car park then picked up again...). Acetic acid may be weak, but how much has the rope been exposed to, and where?

In reply to jimtitt:

I believe there are a couple of major climbing accidents that have been attributed to Formic acid degredation of climbing rope so I cenrtainly wouldn't place too much faith in a rope that has been smeared with acetic acid, although I'd suspect that the actual concentration of acetic acid in silicone sealant would typically be quite low.

In reply to jimtitt:


Jim, I'm sure you have seen this: http://www.bergundsteigen.at/file.php/archiv/2003/2/42-49%20%28heilamseil%2...

Your German will be far better than mine but a translation here: http://www.ukclimbing.com/forums/t.php?t=416564 suggests that acetic acid does not damage nylon rope.

In reply to duncan:
I use http://www.coleparmer.com/techinfo/ChemComp.asp or http://www.omsdive.com/nylon_chem_chart.html both of which (and a number of others) give the effects as `severe´.
That said, the amount given off by a bit of silicone sealant wouldn´t trouble me for one second!

In reply to Reach>Talent:

really?

I heard about the ab sling tat that was left on a crag next to an ants nest as reported on UKC but nothing else.

In reply to duncan:
I have information from beal that lists chemicals and concentrations that ropes are resistent to. I believe acetic acid is OK up to 40% concentration but not above that.

In reply to CurlyStevo:

It's hard to be definitive about what is OK and what isn't, because much of the available information is incomplete.

However, I've got a data sheet on Enkalon and Enka Nylon fibres (the main EU producer of the raw material) which I got from Beal or Petzl; all it says about Acetic Acid is that 5% conc at 100oC for 10 hours gives a reduction in tensile strength of between 10-50%.

This isn't very suprising; nylon is resistant to most chemicals including most alkalis and hydrocarbons, but many acids attack it. In general, the stronger and more concentrated the acid (2 different things btw), the worse the effect.

I have no idea how much acetic acid would be present, if any, in the silcone though. If there is, it should be labelled as an irritant at least, so if the container you used says nothing, then I suspect there isn't enough to worry about. As ever, it's the user's call; if in doubt, throw it out!

In reply to Dan Middleton, BMC:

A Loctite safety datasheet says that it is released at 3-5% concentration..
From my electronics experience, silicone rtv eats copper plate like there is no tomorrow. Vinegar is 5% and does not eat copper..
I assume that the silicone involved was actually acetoxy-cure and we're not all discussing the wrong thing?

thanks for your input boys ive decided to put it on ebay.



just kidding ive cut it ,on the bright side ive 2 ropes now and just need to take one on short abs less weight.

In reply to Dan Middleton, BMC:
yes just checked my documentation and it's the same as yours. The information is a bit useless as when do you boil acetic acid and then put it on your ropes.

For example look at the formic acid part of chart 5% at 100 degrees c for 10 hrs is partially resistant while 40% at 21 degrees c is completely resistent.

Anyway OP has made a choice now.

Stevo