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Mixing Metal on Anchor Chains. Thoughts? Experience?


Jim Titt · · Germany · Joined Nov 2009 · Points: 490
eli poss wrote:

2 reasons:

  1. It gives you more flexibility in where to drill your bolts if you aren't using a pre-determined length of chain
  2. Not all manufacturers of hardware makes this kind of set up so if people aren't buying hardware from you or already have hardware from other manufacturers they can do this. 

Also, I didn't realize you can put the pig tail straight on a regular hanger, I thought that only worked for glue-ins. 

They fit any chain you can get a 10mm bar through and every known type of hanger (except pop-tops where the orientation would be wrong).

The only time there are problems are with glue-in bolts or staples which have been installed too near the rock (like Fixe bolts which have been recessed too deep and no longer conform to the standard) but a) that´s not my problem b) they will fit if your hammer is big enough.

Ken Chase · · Toronto, ON · Joined Apr 2011 · Points: 0

Had a question, found this thread, and some interesting points here. Sorry to revive an old thread (only a few months, right?)

My question: instead of PS chain, how about grade 70 ('gold transport chain' - with gold chromate finish)? It's not rated for 'overhead lifting' but at 5/16" its in the WLL > 3000lbs (I think there's some elongation required in the spec for grade 80 lifting chain before breaking, which 70 might not have, but we use ropes).

There's some G70 in a couple local areas around S. Ontario here that've stood up quite well over time but could be just those installs where PS woulda worked too. (There's also some newer PS chain there, so we'll see how the PS wears in comparison).

My main Q was just wondering if the gold chromate finish was MORE noble than SS304 which might in fact encourage corrosion of the 304 bolt/hanger, which is much worse.

As for Mussy Hooks, found this thread indicating a failure mode due to twisted rope;

http://www.supertopo.com/climbers-forum/2731151/Beware-the-Mussy-Hook

Additionally I too have found missing gates on them in the wild quite often. $6 is nice * 2 hooks, but then throw in like $6.50 304 QL's and a hanger, and that doesn't compare to $8.50 for a ring-on-a-hanger (Canadian prices... :) )

As for Rams Horns/Pig Tails, seen some (I have a picture I cant find now..) where it's a U shape bent into the familiar curve - so two arms into the wall on one piece of metal. (People are even less clued on how to use those however...)

Ken Chase · · Toronto, ON · Joined Apr 2011 · Points: 0

From a metallurgist friend:

"I would still say that 304 would act as the more noble material if you had contact between 304 and the chromate-zinc coated SA516 gr.70. Intrinsically the chromate coating might actually be more oxidizing/noble because the chromium can exist in a higher oxidation state compared to the chromium in the passive oxide on the surface of 304. However I would expect the chromate-zinc film to tend to be more unstable in service compared to the compact chromium oxide passivating 304, thus leading to a less noble material in use.

DrRockso · · Red River Gorge, KY · Joined Sep 2013 · Points: 341

The gold chain seems to resist rust longer than your average plated chain, but will not hold up as long as 304SS chain. Increased corrosion on the 304 hanger is not a concern. Climb Tech Top Anchor Hooks (Mussy hooks) have a proper rated climbing wiregate which will prevent the issue you're describing, it seems having them on chains vs. directly on a 1 quicklink attached to the hangers would also prevent some of the twisting apparent in the report.

Rob the tricam · · Springdale, Utah · Joined Sep 2009 · Points: 0

These are 5 bucks, no quick link needed due to the cleavis, 12500lbf breaking strength. Hey are an inch across for the rope and have a deep basket for the rope to be far away from the gate.

These are the way to go with wave bolts. 

https://www.amazon.com/gp/aw/d/B000LOKBD6/ref=psdcmw_15737571_t3_B000LOKBC2#

DrRockso · · Red River Gorge, KY · Joined Sep 2013 · Points: 341
Rob the tricam wrote: These are 5 bucks, no quick link needed due to the cleavis, 12500lbf breaking strength. Hey are an inch across for the rope and have a deep basket for the rope to be far away from the gate.

These are the way to go with wave bolts.

https://www.amazon.com/gp/aw/d/B000LOKBD6/ref=psdcmw_15737571_t3_B000LOKBC2#

Last year we had a catastrophic failure of this design at the Red River Gorge, the little "r-key" that holds the clevis pin on can rust out or break and with just a little vibration the pin comes out causing system failure. I think for just a quicklink and a dollar more the Climb Tech version http://www.climbtechgear.com/top-anchor-hook/ with a climbing rated wire gate is a much better design. 

Rob the tricam · · Springdale, Utah · Joined Sep 2009 · Points: 0

In a humid environment, the r clip is the weak link. I have epoxyed them in place to combat this if the area calls for it

Harumpfster Boondoggle · · Unknown Hometown · Joined Apr 2018 · Points: 0
Rob the tricam wrote: These are 5 bucks, no quick link needed due to the cleavis, 12500lbf breaking strength. Hey are an inch across for the rope and have a deep basket for the rope to be far away from the gate.

These are the way to go with wave bolts. 

https://www.amazon.com/gp/aw/d/B000LOKBD6/ref=psdcmw_15737571_t3_B000LOKBC2#

Yea, don't use those. 

Trusting your life to a 1/4 cent cotter pin is not sound policy.
Ken Chase · · Toronto, ON · Joined Apr 2011 · Points: 0

So then we're back to attaching those sexy climbtech anchors to a hanger, or a chain anyway, need a quicklink - plated steel ok on plated steel anchor? Or do we want to ensure the rust occurs on the giant hook only since it will wear more slowly? If so, a SS QL is ~$6 too. Starts adding up. (Covered in multiple other threads though...)

Harumpfster Boondoggle · · Unknown Hometown · Joined Apr 2018 · Points: 0

Imo, plated steel quick links are fine...because they are easily replaceable.

Its when you do things like place galvy bolts that are a pita to remove and replace that it becomes more problematic. Mixed metals in the chains etc should be no biggee.

As well, it is a far bigger deal to use galvy bolts with SS hangers as the difference in electrical potential in the two metals (plus water in the hole itself) greatly accelerates SCC.

DrRockso · · Red River Gorge, KY · Joined Sep 2013 · Points: 341

I'm sensing the end of this thread! Something, something, something, galvanic corrosion! :)

DrRockso · · Red River Gorge, KY · Joined Sep 2013 · Points: 341

BTW not the biggest fans of the mussy's straight on the bolts when the gap is too far and gets your rope all twisty, so usually using a quickink or quicklinks and chain suits me. 

Guideline #1: Don't be a jerk.

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