Mixing Titanium anchor hardware with SS glue-ins

Here's my dilemma: A local route at a seaside crag has SS glue-ins (not sure if it's 304 or 316), but no anchor hardware. Most people lead up, thread the two glue-ins and rap, but I've noticed more and more folks top roping directly through the bolts. These bolts show little sign of corrosion (over ~3 years), but will likely need to be replaced with titanium, as we've done with most other routes at this crag.

Is there much galvanic corrosion between SS bolts and Titanium hardware? 

If so, then I'll add a 316 SS anchor set and just hope it doesn't need to be replaced before the glue-ins. If not, then I'll probably go with the Titan Rams Horns (the bolts are not offset, so the Titan Lower Off Anchor Set won't work).

Jamie Collins wrote: Here's my dilemma: A local route at a seaside crag has SS glue-ins (not sure if it's 304 or 316), but no anchor hardware. Most people lead up, thread the two glue-ins and rap, but I've noticed more and more folks top roping directly through the bolts. These bolts show little sign of corrosion (over ~3 years), but will likely need to be replaced with titanium, as we've done with most other routes at this crag.

Is there much galvanic corrosion between SS bolts and Titanium hardware? 

If so, then I'll add a 316 SS anchor set and just hope it doesn't need to be replaced before the glue-ins. If not, then I'll probably go with the Titan Rams Horns (the bolts are not offset, so the Titan Lower Off Anchor Set won't work).

Titanium has a galvanic index of .3V while stainless has a galvanic index of .5V (316) or .6V (304).  For a point of reference, carbon steel has a galvanic index of .85V, so you would expect a slightly slower galvanic reaction between the titanium and the stainless than you would between the stainless steel and carbon steel (.2V to .3V difference vs .25V to .35V difference). 

Ken Noyce wrote:

Titanium has a galvanic index of .3V while stainless has a galvanic index of .5V (316) or .6V (304).  For a point of reference, carbon steel has a galvanic index of .85V, so you would expect a slightly slower galvanic reaction between the titanium and the stainless than you would between the stainless steel and carbon steel (.2V to .3V difference vs .25V to .35V difference). 

Ok, thanks. That's still a big enough difference to concern me, so I'll just go with stainless and replace the anchor hardware earlier than the bolts if I have to.

Yes, there will be galvanic corrosion (or so I'm assured by experts).  But, just a suggestion, why don't you go up once and replace the SS with Ti bolts/horns/etc.?  Instead of having to do it twice?

And another question for you: I know you've had some Ti anchor bolts in use out there since about 2001, right?  (Sex Porpoises)  Have people been lowering directly from the Ti anchors all this time?  Has anyone mentioned that the anchor bolts, or Ti anchor bolts on any climb, are showing any wear?

I would try to replace the SS bolts with Ti now (instead of waiting 10 years), but I’ve never replaced glue-ins. Part of me is hoping that, in the intervening decade, we’ll have discovered a better technique for removing glue-in bolts.

And this is actually at a different crag, but I haven’t noticed any wear on any of the climbs with older Ti anchors in the area (eg, Sex Porpoises at Mickey’s). It’s hard to say how many people lower off directly through the bolts instead of rappelling. My guess would be somewhere around 50/50. Some of those anchor bolts are Titan U-bolts but others are equipped with older Tortuga-style as well.

It’s good to see that most new climbs are being equipped with Titan Eternas and the full Titan Eterna Lower-off set. 

Jamie Collins wrote: I would try to replace the SS bolts with Ti now (instead of waiting 10 years), but I’ve never replaced glue-ins. Part of me is hoping that, in the intervening decade, we’ll have discovered a better technique for removing glue-in bolts.

Better than what?  Martin has removed Ti glue-ins by heating the bolt with a torch.   The glue melts/burns/softens and the bolt can be pulled out.   The hole can then be drilled again.  I would expect that this would work just as well with SS glue-ins.   Don't forget your oven mitts.

And this is actually at a different crag, but I haven’t noticed any wear on any of the climbs with older Ti anchors in the area (eg, Sex Porpoises at Mickey’s). It’s hard to say how many people lower off directly through the bolts instead of rappelling. My guess would be somewhere around 50/50. Some of those anchor bolts are Titan U-bolts but others are equipped with older Tortuga-style as well.

It’s good to see that most new climbs are being equipped with Titan Eternas and the full Titan Eterna Lower-off set. 

Okay, it's good to know that you've seen no wear.  Thanks.  

On Cayman Brac we lower and top rope directly through the Tortuga anchor bolts.   There is no measurable wear on even the oldest (15 years) bolts.  I took a micrometer down there two years ago.  You can see a shiny spot where the rope rubs, you can feel it with your fingers (smoother) but the micrometer couldn't measure any difference (<.001").

So while it doesn't hurt to have the full Ti lowering set, it may not be necessary.  

John Byrnes wrote: There is no measurable wear on even the oldest (15 years) bolts.

Wow, thanks. That’s quite impressive. The idea of TRing through anchor bolts seems so anathema to me, but I’m probably making a big deal about (almost) nothing. 

Jamie Collins wrote:

Wow, thanks. That’s quite impressive. The idea of TRing through anchor bolts seems so anathema to me, but I’m probably making a big deal about (almost) nothing. 

I would partially blame this on the fact that the insurance company for one of the large gym chains in the bay area made them stop offering a sport anchors class, which was immensely valuable. Also just the general explosion of climbing in the bay. 

John Byrnes wrote: Better than what?  Martin has removed Ti glue-ins by heating the bolt with a torch.   The glue melts/burns/softens and the bolt can be pulled out.   The hole can then be drilled again.  I would expect that this would work just as well with SS glue-ins.   Don't forget your oven mitts.

Okay, it's good to know that you've seen no wear.  Thanks.  

On Cayman Brac we lower and top rope directly through the Tortuga anchor bolts.   There is no measurable wear on even the oldest (15 years) bolts.  I took a micrometer down there two years ago.  You can see a shiny spot where the rope rubs, you can feel it with your fingers (smoother) but the micrometer couldn't measure any difference (<.001").

So while it doesn't hurt to have the full Ti lowering set, it may not be necessary.  

How much traffic do those routes actually see, though? Here in Durango, most people lower or rap directly through the eye of SS glue-ins unless they walk off and I've seen some visible wear in just the 5 years I've been here.

Granted that's SS and not Ti but I think it's still worth it to have wear concenrated on components that are very easily replaceable because it will wear out eventually. There's a good chance that it will wear out before it's time to replace the bolt, at least on high traffic routes.

​Not sure about Cayman Brac, but I can think of certain Bay Area routes that see a huge volume of traffic (ie, unless you arrive before 9 or after 5, it’s nearly impossible to go there on the weekend and not see someone climbing them — and that’s probably ~11 months/year) but the Ti anchor bolts show no visible wear. 

I think that’s just due to the difference between Ti and SS. That said, if I was equipping a new route, I would include replaceable anchor hardware. It’s not that much more expensive. 

eli poss wrote:

How much traffic do those routes actually see, though? Here in Durango, most people lower or rap directly through the eye of SS glue-ins unless they walk off and I've seen some visible wear in just the 5 years I've been here.

Granted that's SS and not Ti but I think it's still worth it to have wear concenrated on components that are very easily replaceable because it will wear out eventually. There's a good chance that it will wear out before it's time to replace the bolt, at least on high traffic routes.

Eli, you are welcome to come down and put Ti lowering rings on all the routes.    Let's see, since the bolts are in place, it'll only cost you $45 per route.  So $4500 + shipping -- peanuts for you, right?  Probably only take you a couple weeks to do the work.  No problem.

John Byrnes wrote:

Eli, you are welcome to come down and put Ti lowering rings on all the routes.    Let's see, since the bolts are in place, it'll only cost you $45 per route.  So $4500 + shipping -- peanuts for you, right?  Probably only take you a couple weeks to do the work.  No problem.

I wish I could afford to even get to the island, much less equip all the routes there. I've got my own routes that need equiping and a rebolting project to work on this summer so I'm a bit busy for a trip to the Caribbean. But thanks for the offer, though.

Again, how much traffic do those routes see? A major destination like RRG? A small group of dedicated locals? Somewhere in between?

eli poss wrote:

I wish I could afford to even get to the island, much less equip all the routes there. I've got my own routes that need equiping and a rebolting project to work on this summer so I'm a bit busy for a trip to the Caribbean. But thanks for the offer, though.

Again, how much traffic do those routes see? A major destination like RRG? A small group of dedicated locals? Somewhere in between?

Since you didn't get the sarcasm in my previous post, let me spell it out for you.   

The amount of traffic is irrelevant because we know there's been zero wear in 15 years (actually 18 now).   So, how long will the anchor bolts last, Eli?   Since zero divided by 15 is still zero, a classical approach is meaningless.  

So let's guess .001" per 30 years, and we'd want to retire the bolts when they are 2/3 worn, so a conservative estimate is roughly  262 years.    So do you still "think it's still worth it" to spend $4500 and several hundred hours to upgrade the anchors?     I'll be dead, you'll be dead, as will your grandchildren should anyone be so irresponsible as to mate with you, most of the island will have been inundated due to global warming, and it'll be too hot to climb there anyway.

I'm not embarrassed that my anchor bolts will need to be replaced in 2.5 centuries.    At least fishermen can moor their boats to them.

John Byrnes wrote:

Since you didn't get the sarcasm in my previous post, let me spell it out for you.   

The amount of traffic is irrelevant because we know there's been zero wear in 15 years (actually 18 now).   So, how long will the anchor bolts last, Eli?   Since zero divided by 15 is still zero, a classical approach is meaningless.  

So let's guess .001" per 30 years, and we'd want to retire the bolts when they are 2/3 worn, so a conservative estimate is roughly  262 years.    So do you still "think it's still worth it" to spend $4500 and several hundred hours to upgrade the anchors?     I'll be dead, you'll be dead, as will your grandchildren should anyone be so irresponsible as to mate with you, most of the island will have been inundated due to global warming, and it'll be too hot to climb there anyway.

I'm not embarrassed that my anchor bolts will need to be replaced in 2.5 centuries.    At least fishermen can moor their boats to them.

I'm not suggesting that you add hardware to those routes as it seems they don't see enough traffic to warrant them. But I don't think that generalizing that practice to all Ti glue-ins in all places is appropriate until there is more information available about the wear resistance. Presumably, somewhere in the Bay area is going to see more traffic than cayman brac so using a different approach may be appropriate.  

eli poss wrote:

I'm not suggesting that you add hardware to those routes as it seems they don't see enough traffic to warrant them. But I don't think that generalizing that practice to all Ti glue-ins in all places is appropriate until there is more information available about the wear resistance. Presumably, somewhere in the Bay area is going to see more traffic than cayman brac so using a different approach may be appropriate.  

Don´t panic, it´s John with his normal wild hyperbole! He originally claimed titanium bolts last ten times longer than stainless based on HIS dubious measurement of one bolt in an obscure place, even the manufacturer of the bolts had to join in and admit that this probably wasn´t the case and that the ASTM tests showed that titanium´s industry wide reputation as a poor wear-resistant material was justified. There are two tests and the one most closely related to climbing use (G65) involves rubbing abrasive material onto the metal with a polymer-rubber wheel which is as near as a grit-impregnated rope as you are likely to get and for example Budinski showed that the material removal for Grade 2 titanium is over double that of 316 stainless steel.

It´s better just not to make any claims about titanium wear and longetivity as this is a complicated topic which could backfire  

eli poss wrote:

I'm not suggesting that you add hardware to those routes as it seems they don't see enough traffic to warrant them. 

Really?  Then what were you suggesting when you wrote "...but I think it's still worth it to have wear concenrated on components that are very easily replaceable because it will wear out eventually. There's a good chance that it will wear out before it's time to replace the bolt, at least on high traffic routes." ??   (Actually, don't bother.)

Eli, what you fail to understand is that if you are measuring the wear periodically, it doesn't matter how much traffic there is.   The "traffic" is integrated into the wear/year number which is currently zero.  The evidence I have so far is that the anchors on Cayman Brac will never wear out.    I'd be happy with half of that ;-)  

What YOU are doing is jumping to a conclusion (a very costly conclusion that you expect someone else to pay for) that you have no evidence for, based on a different material in a different environment.   By emphasizing "traffic" you attempt to somehow justify your speculation.  You make similar statements on many different forum topics, which is why you have the reputation you do.

But I don't think that generalizing that practice to all Ti glue-ins in all places is appropriate until there is more information available about the wear resistance. Presumably, somewhere in the Bay area is going to see more traffic than cayman brac so using a different approach may be appropriate.  

The jury is still out regarding lowering on Ti anchors, which is why I asked Jamie about it.  And he wrote: "Bay Area routes that see a huge volume of traffic (ie, unless you arrive before 9 or after 5, it’s nearly impossible to go there on the weekend and not see someone climbing them — and that’s probably ~11 months/year) but the Ti anchor bolts show no visible wear." 

Eli, repeat after me: Huge traffic and no visible wear.  So until we have evidence to the contrary, YES it is appropriate to generalize.  

So you are wrong as usual.   And as usual, you'll probably just continue to equivocate.

I never made any suggestion for any of the routes or hardware on cayman brac. You're beating to death a straw man for that one. I'm talking about the routes referenced in the OP. From the information provided in this thread, I have gathered that the existing Ti bolts at this crag have seen no wear but have only been used for 3 years. I would expect those bolts to last at least 100 years and ideally you want the lowering hardware to be easily replaceable unless it's going to last as long as the bolt itself.

I don't think 3 years is enough to provide a good picture of how it will hold up in a much longer time span. All I'm saying is that you're comparing apples to oranges John, and so one should consider that before generalizing the practices of cayman brac to a higher traffic area.

Jim Titt wrote:

Don´t panic, it´s John with his normal wild hyperbole! 

That's right.  When I published my first article about SCC in stainless climbing bolts in 2001, it was considered wild hyperbole even though I referenced two formal metallurgical analyses.   It wasn't until Angele Sjong published her article 7 years later that more than a few people believed me.  Now, SCC issues are incorporated into the UIAA guidelines.   Guess I had the last laugh, eh?

He originally claimed titanium bolts last ten times longer than stainless based on HIS dubious measurement of one bolt in an obscure place, even the manufacturer of the bolts had to join in and admit that this probably wasn´t the case and that the ASTM tests showed that titanium´s industry wide reputation as a poor wear-resistant material was justified. There are two tests and the one most closely related to climbing use (G65) involves rubbing abrasive material onto the metal with a polymer-rubber wheel which is as near as a grit-impregnated rope as you are likely to get and for example Budinski showed that the material removal for Grade 2 titanium is over double that of 316 stainless steel.

It´s better just not to make any claims about titanium wear and longetivity as this is a complicated topic which could backfire  

Actually Jim, I've measured a number of bolts, and thank God they were in an obscure place.  I hate crowded crags.

As far as G65, it'd be a relevant test if we climbed in a laboratory with ropes made of rubber with a continuous coating of wet sand on them, AND if real-world evidence was consistent with G65 projections.   Got any real-world evidence, Jim?

John Byrnes wrote:
Eli, what you fail to understand is that if you are measuring the wear periodically, it doesn't matter how much traffic there is.   The "traffic" is integrated into the wear/year number which is currently zero.  The evidence I have so far is that the anchors on Cayman Brac will never wear out.    I'd be happy with half of that ;-)  

I suspect that even the dumbest member of Mountain Project can actually work out that if the route is never climbed there will be no wear and the bolt will last forever  

John Byrnes wrote: As far as G65, it'd be a relevant test if we climbed in a laboratory with ropes made of rubber with a continuous coating of wet sand on them, AND if real-world evidence was consistent with G65 projections.   Got any real-world evidence, Ji

Well we could see if real-world testing gives similar results by performing a simple, controlled experiment rather than haphazard anecdotes:-

First I dug out an old test rig which I built to measure rope wear and changed it a bit. At the bottom is a steel plate which is free to move and fitted with two identical chain links, one is 8mm stainless steel and the other 8mm Gr 2 Titanium.

Then a 10mm climbing rope is installed in a W form so centre of the W is knotted into the winch hook and the outer legs run through pulleys and have equal weights attatched. The weights are adjusted to give 80kg tension on the inner strands when lifting. To make the rope consistantly "dirty" and speed things up a bit the links and the plate are buried in a box of dry, sandy soil from my greenhouse.
Then the winch cycles up and down, 1.6m per stroke and I watch with boredom setting in.
Every 100 cycles I stop and measure with a digital caliper, change the rope and turn the bottom plate around in case there is some bias to one side or the other.

100 cycles Stainless steel 7.52mm. Titanium 7.07mm.
200 cycles Stainless steel 6.76mm. Titanium 5.74mm
300 cycles Stainless steel 6.07mm. Titanium 4.37mm
400 cycles Stainless Steel 5.53mm (upper photo).Titanium (lower photo). 3.57mm

So after 400 cycles (1280m) of dirty rope the stainless steel link has lost 2.47mm of it´s diameter and the titanium one has lost 4.43mm of it´s diameter, clearly the results of ASTM G65 are reasonably similar to our real life test. Or simply put titanium wears roughly twice as fast as stainless steel (which a tribology text book such as Surface Engineering of Light Alloys had already told us and better still explained why).

THEN!
We could consider what this means. Wear is of concern because a) a sharp edge is created which can damage the rope and b) the part is weakened.
a) clearly occurs roughly twice as fast with titanium as stainless steel.
b) because the titanium part starts out with half the strength of the stainless part AND it wears twice as fast it reaches the point at which, for example the two no longer achieve the required 25kN, FOUR times faster than the stainless steel part. (An 8mm titanium bolt will hold 38kN whereas a stainless steel one holds 79kN, both start with the same cross-sectional area of 50.27mm² and to weaken the titanium bolt to 25kN we need to remove 17.12mm² of material whereas for the stainless bolt we need to remove 34.18mm² of material,i.e twice as much metal at half the speed).

When considered from a wear point of view and looking at the current market prices of comparable products the stainless components have an economic advantage of between ten and 15 times over titanium.

Nicely done, Jim!