Replacing Anchor Chains


Original Post
Chris Charron · · Unknown Hometown · Joined Feb 2013 · Points: 5

Following some of the recent discussions regarding "Lower off chains because it's safer" vs "Rappel to Prevent wear" and assuming I want to give back to the climbing areas I use, and keep them safe. 

What chain is safe to use to replace worn chain? 

Naturally, buying chain from a climbing supplier is good. Hardware store is mixed (most likely not good).

Near where I live is a Marine/Industrial surplus store, they have a variety of chain, both 316 and Zinc plated. What should be used? What WLL would be the minimum to be considered safe? Size important beyond being strong enough, and big enough for the rope to pass through?

Chris Charron · · Unknown Hometown · Joined Feb 2013 · Points: 5

Russ Walling · · www.FishProducts.com · Joined Oct 2004 · Points: 3,160

Donate to your local crag maintenance fund.  From your post above, I'm thinking you might not know what you are doing.  

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Chris Charron wrote:

Following some of the recent discussions regarding "Lower off chains because it's safer" vs "Rappel to Prevent wear" and assuming I want to give back to the climbing areas I use, and keep them safe. 

What chain is safe to use to replace worn chain? 

Naturally, buying chain from a climbing supplier is good. Hardware store is mixed (most likely not good).

Near where I live is a Marine/Industrial surplus store, they have a variety of chain, both 316 and Zinc plated. What should be used? What WLL would be the minimum to be considered safe? Size important beyond being strong enough, and big enough for the rope to pass through?

I make chainsets commercially and for us the chain is only a joining element to something else which takes the wear, personally I can´t fall in love with the American system of threading through the bottom link but that´s me. Size is what matters, 5/16" hasn´t a lot of material before it will wear again and it´s a bit small for threading the rope, 3/8" is the smallest I´d use.

We normally install 10mm or 12mm rings and even specially make a 12mm "chain link" for the bottom unit since the rest of the chain sees no wear.

The WLL is irrelevant, it is calculated using a bizarre system which varies from country to country and the purpose the chain is intended for, anything you can get a rope through is strong enough.

Russ Walling · · www.FishProducts.com · Joined Oct 2004 · Points: 3,160
Jim Titt wrote:

I make chainsets commercially and for us the chain is only a joining element to something else which takes the wear, personally I can´t fall in love with the American system of threading through the bottom link but that´s me.

Yeah, that is a bad system.  Chain with at a minimum a quicklink that is replaceable is much preferred to raw chain links

eli poss · · Durango, Co · Joined May 2014 · Points: 456

Unless the chain is so worn or corroded that the strength is affected then your best bet would be to just throw a quicklink or better yet a steel biner onto the chain. If you choose not to go with the steel biner then get the fattest quicklink that can still fit through the chain.

If you replace the chain, still get a quick link or steel biner to put on the end so that it can be replaced when worn/corroded without replacing the entire chain. I don't remember the size (either 3/8 or 7/16), but this is chain I like because it is beefy for wear and also wide enough to fit any biner or rope that would conceivably be used these days. A size down in chain would be acceptable, but it's to just spend the extra few dollars to make sure that nobody will ever encounter any issues with a rope or biner that is too fat to get through the chains. I included a nano 22 carabiner for size reference

kenr · · Unknown Hometown · Joined Oct 2010 · Points: 10,240
Chris Charron wrote:

What chain is safe to use to replace worn chain? 

My understanding is that you have to think carefully about the total system. Wear on the chains is the easy part, because you can see what the state of the metal is, and (comparatively) it's not much work to replace them. And if somebody does not agree with or does not trust either the current state or what you did to replave the previous state, they can just thread their own nylon webbing/sling or cord through the anchor bolts/hangers.

The hard problem is corrosion in the underlying bolt and its interface with the rock -- which you can't see to inspect, and much more work to replace -- and not much choice about trusting it even if you don't agree with the maintenance policy for it.

Key point: My understanding is that attaching stainless steel external fixtures (e.g. chain) to a plated-steel bolt (or plain-old unplated carbon steel) will tend to _accelerate_ the corrosion of the mostly-invisible underlying "fundamental" bolts in the anchor.

That's why you need to talk to knowledgeable local people who maintain the bolts.

Ken

P.S. If in doubt, better to use plated-steel for external fixtures. They might show corrosion sooner (but that's comparitively easy to detect and fix) -- and it will exacerbate the tough "fundamental" problem of bolt corrosion - (might even help slow corrosion of bolts, if the underlying bolts are stainless).

P.P.S. While you're at it ... how about look at some more modern approaches than just chains which other USA areas are installing for making top-roping and lowering-off more convenient for growing numbers of climbers. 

eli poss · · Durango, Co · Joined May 2014 · Points: 456
kenr wrote:

Key point: My understanding is that attaching stainless steel external fixtures (e.g. chain) to a plated-steel bolt (or plain-old unplated carbon steel) will tend to _acccelerate_ the corrosion of the mostly-invisible underlying "fundamental" bolts in the anchor.

My understanding is that this is the case for the hanger attached to the bolt, but not really an issue for quicklinks or chain attached to the hanger because any galvanic corrosion is easily detected on the hanger and that galvanic corrosion is unlikely to happen anyways because water and minerals won't be trapped inside a bolt hole.

T Roper · · DC,VA,NM,UT,CT,MA · Joined Mar 2006 · Points: 860

there is nothing hard about borrowing chain/bolt cutters and snapping a link  off and adding a quicklink. or just flip the chain and take 2 links out of the system assuming its an odd number so the rope runs strait.


Guideline #1: Don't be a jerk.

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