Heads up -- this biner turned my rope black

https://www.blackdiamondequipment.com/en_US/hotforge-screwgate-carabiner-BD210161_cfg.html

I was using a couple of these as my top rope anchor at a local crag, and the black paint or something rubbed off onto my rope. Really a drag because then when you handle the rope, the black stuff gets all over your hands and clothes. 

Eric Metzgar wrote:

I was using a couple of these as my top rope anchor at a local crag, and the black paint rubbed off onto my rope. Really a drag because then when you handle the rope, the black paint gets all over your hands and clothes. 

Yeah, no. There is not enough paint in the rope/carabiner friction zone to do that to the whole rope.

Aluminum from anchors/quick draws/belay carabiner is more likely to rub off onto your rope and make it black. 

No, you're confusing black anodize with aluminum oxide. Carabiners are anodized (not painted) to give them color. That's why Neutrinos and cam lobes come in different colors. Over time, the anodizing - which is only a few mils thick - wears off and the aluminum "rusts" (oxidizes). That (and dirt) is what makes your rope and hands black.

wivanoff wrote:

No, you're confusing black anodize with aluminum oxide. Carabiners are anodized (not painted) to give them color. That's why Neutrinos and cam lobes come in different colors. Over time. the anodizing - which is only a few mils thick - wears off and the aluminum "rusts" (oxidizes). That (and dirt) is what makes your rope and hands black.

Thanks for the clarification. Whatever it is, it doesn't happen with my "unpainted" carabiners. 

Any aluminum carabiner will have this effect. You can reduce it by using steel carabiners or carabiners with a steel insert such as edelrid bulletproof biners for your anchors but you will still get some residue from quickdraws places lower on the route. 

Yea I'm also getting tired of red, yellow, blue, and green hands depending on the paint color on my biners that day... that's why I've started dipping all of my biners in battery acid before attacking them with an angle grinder to get the paint off before I use them!

Eric Metzgar wrote:

Thanks for the clarification. Whatever it is, it doesn't happen with my "unpainted" carabiners. 

There's such a thing as clear anodize, too. Just because they are "natural" color does not mean they are not anodized.

What actually happens, I believe, is that small aluminum particles rub off onto your rope and then the particles oxidize black.

Found this too:

http://www.supertopo.com/climbers-forum/2065143/Black-Rope-Syndrome-what-s-up-with-ropes-and-aluminum

A couple steel carabiners for the rope end of your anchor quickdraws (and for your 1st draw on the route) goes a long way to keeping the rope clean and making all your other draws last longer (as they don't get beat up serving as anchor draws).

Toprope through steel carabiners and your problem is solved. 

wivanoff wrote:

There's such a thing as clear anodize, too. Just because they are "natural" color does not mean they are not anodized.

What actually happens, I believe, is that small aluminum particles rub off onto your rope and then the particles oxidize black.

Aluminium oxide is actually white, just on your rope (or hands) it's a nano-layer so looks black.

Eric Metzgar wrote:

Thanks for the clarification. Whatever it is, it doesn't happen with my "unpainted" carabiners. 

Eric, are you convinced that it is simply Aluminum oxide, which is a common occurance as carabiners wear, or do you still feel that the coating on the black BD carabiners are doing this? 

Right, the Edelrid Bulletproof carabiner has a steel insert. Totally what we are talking about. My friend bought some for her toprope draws.

Billcoe wrote:

Eric, are you convinced that it is simply Aluminum oxide, which is a common occurance as carabiners wear, or do you still feel that the coating on the black BD carabiners are doing this? 

Don't know actually. I'm just tracking everyone's thoughts on this thread.