Cavechat.org

An interesting article about acid exposure to nylon and harnesses. This will make you think twice about where you store and even put down your harness.
http://www.blackdiamondequipment.com/en ... rness.html

Thanks Scott! I was actually about to post this link as I felt it was valuable and relevant to caving equipment since most of what we use is made of nylon! I've always heard that H2SO4 is bad for ropes but this is the best quantitative testing I have seen. Never heard of the pink thing though!

James

Hey that's really cool. Interesting (and scary!) results.

Makes me wonder if they could somehow add an indicator thread that is easy to inspect to gear - especially for industrial gear that gets used in questionable environments from time to time.

Yes, thank you for posting that! I always knew that certain acids, sulfuric in particular, were dangerous to get on my ropes and other nylon gear. Sometimes I go caving via canoe, and carry my battery in my vehicle to power a small trolling motor. I always make sure that the battery is in the back of my SUV (or trunk of my car), and my ropes and such are in the back seat. Now I am thinking about all those chemicals stored in my shed in close proximity to my gear...

At least now I will know to look for the pink threads!

Trogman

trogman wrote:At least now I will know to look for the pink threads!

My harness came with red stitching. I doubt I could tell if they turned pink.

Scott McCrea wrote:

trogman wrote:At least now I will know to look for the pink threads!

My harness came with red stitching. I doubt I could tell if they turned pink.

So what do you think caused his harness to deteriorate, Scott? I wonder what kind of car he drives and where his battery is located? My parents Cadillac has it mounted under the rear seat. Some have them mounted under the trunk.

Maybe the new battery he bought had residual on the outside that got into the gym bag fabric or on the harness?

Who knows? They never figured out what the exposure was. Maybe he wore the harness into a poorly treated hot tub or something.

Probably the meth explaination

Acid vapors from the battery it shared the trunk with. Battery acid ~35% v/v more than 2x stronger than the over the counter jug of acid ~15% BD used for testing. Trunk was sealed and got warm, vapors then penetrated his gym bag and contaminated patches of his harness.

Don't store nylon anywhere near flooded lead acid batteries. This has been SOP since at least the 1980s...

Wow... what really shocked me was the decrease in strength from Woolite! I'm at work so I can't check, but I'm pretty sure at least one famous SRT book recommends washing ropes with Woolite.

I always thought that putting Woolite (fabric softener) on ropes sounded like kind of a bad idea.

Lava wrote:Wow... what really shocked me was the decrease in strength from Woolite! I'm at work so I can't check, but I'm pretty sure at least one famous SRT book recommends washing ropes with Woolite.

Given the obviously tiny scale of the test, I don't think it was been proven that Woolite hurts anything, any more than it has been proven that weed killer makes nylon stronger, or that acetone strengthens dynema. 22kn rated products failed at 25.9 and 27 after exposure to Woolite...is that dangerous?

Lava wrote:Wow... what really shocked me was the decrease in strength from Woolite! I'm at work so I can't check, but I'm pretty sure at least one famous SRT book recommends washing ropes with Woolite.

Yes, that has me concerned as well. The BD folks list it as having sulfuric acid, but the ingredients list on the MSDS calls it "Alkylbenzene Sulfonic Acid." http://www.rbnainfo.com/productpro/ProductSearch.do?brandId=36&productLineId=742&searchType=PL&template=1Some of you chemistry experts can perhaps explain the difference, if there is any. The 9% strength reduction is very worrying, since I have used Woolite a few times over the years to wash my rope. One thing to take into account is that the experiment most likely used full strength detergent, whereas in the washer it is highly diluted. All the same, I may start using Arm and Hammer!

Anonymous_Coward wrote:I always thought that putting Woolite (fabric softener) on ropes sounded like kind of a bad idea.

I don't think they were talking about fabric softener. While the listing just says "Woolite," the photo shows what appears to be a bottle of (Woolite Everyday)laundry detergent.

Trogman

Anonymous_Coward wrote:I always thought that putting Woolite (fabric softener) on ropes sounded like kind of a bad idea.

Not sure about the fabric softener but the article that just came out in JCKS is pretty reassuring about using Woolite detergent on rope.

http://www.caves.org/pub/journal/PDF/v7 ... -01-01.pdf

cavedoc wrote:

Anonymous_Coward wrote:I always thought that putting Woolite (fabric softener) on ropes sounded like kind of a bad idea.

Not sure about the fabric softener but the article that just came out in JCKS is pretty reassuring about using Woolite detergent on rope.

http://www.caves.org/pub/journal/PDF/v7 ... -01-01.pdf

Interesting- thanks for sharing. From what I gathered, they washed the items (rope and webbing) in the Woolite and the Lysol 5 times, and it showed no loss of strength. I would love to see a more thorough study, with maybe 20 or so washings. I suspect that the loss of strength in the other study was due to exposure to full-strength detergent. It may be a good idea to mix the detergent in a cup or two of water before putting it in the washer.

I was really hoping some of our more knowledgeable members would explain (in laymans terms) what the difference is between sulfonic acid and
sulfuric acid. If they are essentially the same thing, it doesn't sound like a good idea to be using it on rope and soft vertical gear.

Trogman