Ring hangers on SS bolts?

Found this at a local crag. I've never seen ring hangers like this and can't find it on Fixe's online catalogue. Looks like it's zinc plated? Any idea of this would be an issue in contact with SS bolts?

John Serjeantson wrote:

Found this at a local crag. I've never seen ring hangers like this and can't find it on Fixe's online catalogue. Looks like it's zinc plated? Any idea of this would be an issue in contact with SS bolts?

Not as bad as ss hanger on plated bolt.  The hanger and ring will rust but the bolt won't.  The worst that will happen is rust staining on the SS threads, but I don't think that's a big issue?  It can be cleaned with lemon juice and a brush when the hanger is replaced 

Are you sure the bolt is stainless?

Jim Day wrote:

Are you sure the bolt is stainless?

No not absolutely, but I've got some carbon steel bolts from the local hardware store I use for temporary anchors and they're much shinier. These look stainless to me, at least.

Alec Baker wrote:

Fixe updated those hangers. This is the new version, which doesnt allow people to clip the hanger the old ones used to.

https://fixehardware.com/index.php/fixe-ps-ring-anchor-3-8.html

Are those also zinc plated? Seems like a different colouring? I'm seeing some docs that suggest contact between Zinc plated SS and SS will just erode the outer zinc layer, which I guess would weaken the hanger a fair bit but wouldn't be total corrosion?

The zinc plating on the ring/ hanger will corrode faster than if it was paired with a zinc bolt, and then the carbon steel under will also corrode faster.  But it will most likely be totally fine for the next several decades before becoming dangerous, at which point the hanger can be easily swapped.  The biggest reason to replace the hanger sooner than later is visual appearance/ not to allow the zinc to leave dead lichen streaks below the bolt.

Alec Baker wrote:

There is no such thing as zinc plated stainless steel climbing bolts and hangers. Either stainless steel, or zinc plated plain steel

The cone of 5-piece bolts is zinc-plated stainless steel. But that's definitely an outlier.

Austin Donisan wrote:

The cone of 5-piece bolts is zinc-plated stainless steel. But that's definitely an outlier.

Thanks for the correction.

John Serjeantson wrote:

Are those also zinc plated? Seems like a different colouring? I'm seeing some docs that suggest contact between Zinc plated SS and SS will just erode the outer zinc layer, which I guess would weaken the hanger a fair bit but wouldn't be total corrosion?

Those zinc plated hangers came in a rainbow of colors. My guess is their process wasn't very consistent. Haven't noticed a difference in corrosion resistance, and they shouldn't be used outside anyway. 

John Serjeantson wrote:

Found this at a local crag. I've never seen ring hangers like this and can't find it on Fixe's online catalogue. Looks like it's zinc plated? Any idea of this would be an issue in contact with SS bolts?

The hangers are 'treated' with zinc chromate, hence the yellow colour.

Definitely not for outdoor use or mixing with stainless steel.

Francis Haden wrote:

The hangers are 'treated' with zinc chromate, hence the yellow colour.

Definitely not for outdoor use or mixing with stainless steel.

What's a realistic timeline of these corroding to a dangerous point then? Jim is saying "fine for the next several decades". For wedge bolts, I'd heard a normal lifespan is 25 years.

John Serjeantson wrote:

What's a realistic timeline of these corroding to a dangerous point then? Jim is saying "fine for the next several decades". For wedge bolts, I'd heard a normal lifespan is 25 years.

How long is a piece of string?

Corrosion is specific to the chemical environment and the materials involved. As an example, those hangers would last decades indoors on a climbing wall but less than six months in southern Thailand. Point being that in the absence of specific local experience/knowledge, we can only be guided by recognised best practice. Those hangers do not fall into a best practice category for equipping outdoor sport routes.

Francis Haden wrote:

How long is a piece of string?

Corrosion is specific to the chemical environment and the materials involved. As an example, those hangers would last decades indoors on a climbing wall but less than six months in southern Thailand. Point being that in the absence of specific local experience/knowledge, we can only be guided by recognised best practice. Those hangers do not fall into a best practice category for equipping outdoor sport routes.

It's an interior location in Southern Yukon with ~630mm of precipitation a year. The rock is granitic in nature. 

I didn't mean to ask such an open-ended question, I am aware that corrosion depends on a lot of different factors, but the fact that Jim came back with the idea that these could last decades caught me off guard. Since, from my understanding, under ideal installation wedge bolts only really last a couple decades in the first place. I'm simply trying to get a better idea of how concerning this is and if I should approach the developer. Perhaps their perception is this doesn't change the lifespan significantly and given the hardware match, the hangers are what will corrode first and can be replaced easily.

John Serjeantson wrote:

It's an interior location in Southern Yukon with ~630mm of precipitation a year. The rock is granitic in nature. 

I didn't mean to ask such an open-ended question, I am aware that corrosion depends on a lot of different factors, but the fact that Jim came back with the idea that these could last decades caught me off guard. Since, from my understanding, under ideal installation wedge bolts only really last a couple decades in the first place. I'm simply trying to get a better idea of how concerning this is and if I should approach the developer. Perhaps their perception is this doesn't change the lifespan significantly and given the hardware match, the hangers are what will corrode first and can be replaced easily.

Could be many reasons behind the decision to use those ring & hanger units but it's not an ideal standard of material choice put it that way. 

If the bolts are quality stainless, the ring hangers may start to rust in 10 years or less. It may be 20 years before they have enough rust to be of real concern but they will look like shit long before that. 

You have plenty of time to get together with others to upgrade to corrosion resistant hardware. Adding length to the anchors will be beneficial as well.

Manufacturer specs or industry standards might put a lifespan on stainless steel wedge bolts but practically, there's not much reason to replace them unless they're damaged or corroded.  I agree with everyone saying these hangers aren't for outdoor use and I would never use them for this application.  As for answering the question about time before they're dangerous, even with the location you provided, it could be several decades or it could be years.  But to your point it might be the developers intention to monitor and replace at the first signs of corrosion, I would definitely talk to them about it and find out their plan, and try to convince them to change course.  

Mixing metals is still common practice for wear components like chains, quicklinks, and even the beloved climbtech mussy hooks, so maybe you can get a rough idea of how long before rust starts based on some of those components in the area (although I've heard climbtech mussys take longer to corrode in general for some reason, maybe their mass or something special about their zinc coating?)