A5RP wrote:CClaude wrote:The dyes could have an adverse affect on rope strength. Dyes that are phenolic in nature can strongly interact, and disrupt, the hydrogen bonds of nylon ( which gives the nylon its strength). This is how p-cresol (a phenolic solvent) dissolves nylon-6,6. Disruption of hydrogen bonds is how LiCl aid in the dissolution of polyaramides ( Ie:Kevlar) which are a class of aromatic nylons which are more difficult to dissolve then the aliphatic nylons.
Why be hyper-cheap? An "expensive" pen will always be cheaper then a body bag.
And half the MSDS's i go through are the biggest joke.
I have yet to read about or see any incident of complete rope failure in the last oh lets say 30 years of climbing, from an improperly marked rope.
As anything else in this climbing community, we seem to dwell on certain issues yet keep hush hush about those that are in fact killing people.
First ones that come to mind, complacency, over zealousness and total ignorance of the basics.
Just saying.....
Go to the manufacturers specs towards nylon 6,6 which climbing ropes are made of. Check
http://www.cable-ties.com/catalog/pdfs/ ... resist.pdf ( if I got the link wrong google Vydyne Nylon Resins. Chemical Resistance. If you note, both sulfuric acid and various phenols, including cresols, will dissolve nylons. Sulfuric acid can also hydrolyze the amide bond in aliphatic amides, but is often used to dissolve them. Unless I know both the solvent and the dye, I'm not risking it.
Disrupt the hydrogen bonds of amides ( nylons) and their mechanical bonds go to hell. My doctorate is in polymers and its what I do for a living, but i'm not so arrogant to think I know how every material is going to affect things. unless I test it, its a best guess. My attitude is i know that pure hexanes and benzene and pure gasoline (octane mixtures) don't affect nylon 6,6, but hell if I am going to be the crash test dummy, only to find out there was trace contaminates that do.
I agree that there are more stupid things to address, like poor judgement in gear placements, how the rope is running in conjunction to ones legs, and a multitude of other driver errors.
I also find it stupid for people to be cheap. Buy a rope marker that the manufacturer has tested, and lasts maybe 5-10 ropes, and costs max, $3-5 a rope. Why be so cheap. Its sort of like people bailing on crappy anchors.
And yes, i understand cost of climbing... I destroy multiple ropes and pieces of gear a year.