Bolts for Limestone How Long?

John Byrnes wrote: Yes, it's expensive just like all of Hilti's products. But anything that says "Hilti" on it is also, IMHO, the best quality available. I don't know of any other glues that are significantly less expensive AND near-equal quality.

The Simpon SET-XP22 is stronger than the Hilti RE-500 and less expensive. Simpson's products are also significantly more available, you can get them from Home Depot or Lowes, whereas the RE-500 is not as easy to find. Simpson makes the best epoxies in America IMO.

20 kN wrote: The Simpon SET-XP22 is stronger than the Hilti RE-500 and less expensive. Simpson's products are also significantly more available, you can get them from Home Depot or Lowes, whereas the RE-500 is not as easy to find. Simpson makes the best epoxies in America IMO.

I've never heard of Simpson's before. It may be stronger, in terms of pull-out, but as RE-500 is already about 3 times stronger than the UIAA spec, it's overkill.

Have you used RE-500 before and can you compare the working characteristics for us? I like the longer gel-time for the RE-500, and I like the fact that it sticks to titanium! At one time I thought nothing would stick to it.

John Byrnes wrote: I've never heard of Simpson's before. It may be stronger, in terms of pull-out, but as RE-500 is already about 3 times stronger than the UIAA spec, it's overkill. Have you used RE-500 before and can you compare the working characteristics for us? I like the longer gel-time for the RE-500, and I like the fact that it sticks to titanium! At one time I thought nothing would stick to it.

I have only used the RE-500 on the ground for testing, I have never bolted a route with it so I cant really compare. But the SET-XP22 is a good product, the consistency is appropriate for bolting, and it cures slow enough to allow you to do the thing you need to do when bolting without having to change out the nozzle all of the time. As far as sticking goes, the epoxy is not designed to "stick" to the bolt per se, that is not really how it works. As you know, bolts have notices on them. These notches are critical because without them you could pull the bolt out by hand in many cases. Anyway, the epoxy fills into the notches and causes a physical constriction that prevents the bolt from being removed. The only way for the bolt to come out is for the epoxy to break in the sectors that have filled the notches or for the epoxy-to-rock bond to fail. That is why it is critical to tool many deep notches into the bolt. Threading is the best way to achieve this. But I suspect you already knew that.

As far as the UIAA standard goes, UIAA 123 has no epoxy tensile strength requirements, so I dont know what you are referring to when you are referencing such a requirement. The only thing I saw that UIAA 123 said was that the bolt needed to withstand 20kN tension and 25kN shear.

20 kN wrote: I have only used the RE-500 on the ground for testing, I have never bolted a route with it so I cant really compare. But the SET-XP22 is a good product, the consistency is appropriate for bolting, and it cures slow enough to allow you to do the thing you need to do when bolting without having to change out the nozzle all of the time. As far as sticking goes, the epoxy is not designed to "stick" to the bolt per se, that is not really how it works. As you know, bolts have notices on them. These notches are critical because without them you could pull the bolt out by hand in many cases. Anyway, the epoxy fills into the notches and causes a physical constriction that prevents the bolt from being removed. The only way for the bolt to come out is for the epoxy to break in the sectors that have filled the notches or for the epoxy-to-rock bond to fail. That is why it is critical to tool many deep notches into the bolt. Threading is the best way to achieve this. But I suspect you already knew that. As far as the UIAA standard goes, UIAA 123 has no epoxy tensile strength requirements, so I dont know what you are referring to when you are referencing such a requirement. The only thing I saw that UIAA 123 said was that the bolt needed to withstand 20kN tension and 25kN shear.

Okay, so it's a "binding mortar" just like the now discontinued Hilti C-100, which is what we used back in 2000/2001. I think I like the epoxy better, just MHO.

Unless they changed it, the pullout strength is specified to be >15kN. Did they change it? But anyway, back in 2003 (? I have to look it up) the DAV performed pullout tests of bolts using various glues and binding mortars. The machine they used went up to 40kN and there were two or three that maxed the machine; one of which was RE-500. The tests were run by Dieter Stopper, who was the head of the UIAA Safety Committee at the time.

I can pull the article if you want specifics.

More usually these kinds of products are called chemical mortar, at least in the standards which cover them.

For the bolt side the critical thing is the shear strength of the mortar since this is what prevents the mortar in the threads/notches breaking off, for the rock side the wetting ability is more important so that the mortar can engage into the rock pores, there isn´t any easy way of measuring this except testing. The liquid/glass capsule system is better in this respect but problematic in others, in the 2006 tests by the DAV run by Chris Semmel the Hilti Hit RE500 and the capsule systems got to 60kN which is the limit for their tester. Since all the mortars they tested achieved at least 3 times the requirement all can be considered excellent anyway. (It´s worth noting that they used a longer than usual bolt and one with good mechanical characteristics to achieve this however, these numbers are unachievable with many bolts on the market).

The strongest glue we´ve tested was a Swiss made bulk epoxy grout which we mix with colloidal silica to improve the hardness and usability.We get over 100kN with this but as it only comes in 1.5kg two-part packs use on the cliff is somewhat difficult. Also it takes ages to fully cure and getting a bolt to hold 100kN isn´t so easy anyway.

The UIAA changed to 20kN in 2008 (published 2009) but this is somewhat of an irrelevance and any reasonable bolt/mortar combination will easily achieve this.

The bolt and mortar are approved in combination and the certification for EN959 (and UIAA123) is only for the two together. This aspect is however generally ignored by users.

Hilti HitRE 500 was for many years the gold standard for chemical mortar but time and creativity has put a lot of comparably performing products on the market, I can think of at least 10 comparable products available in Europe at least these days. The colour of the Hilti is a problem, the price even more so! The health issues are more of a worry since it is a fairly agressive product and a number of people have stopped using it for this reason, additionally a few groups such as the British Caving Association ban it´s use as it is poisonous to fish and water-dwelling organisms and caves are generally associated with water resources.

It´s still the glue I recommend for customers in countries where access to alternatives is difficult since Hilti have good distribution and it is a reliable product.

I'm not sure how readily available it is elsewhere, but in Australia 'Powers' PFPRO expoxy is preferred by many. It's strong, economical and has a decent working time in warm climates.

I have to agree with Jim, while Hilti is a quality product it's color and extremely high costs make it a poor choice when many other, quality options are now available. In a time increased scrutiny on fixed anchors, the horrible red Hilti color is a POOR choice that acts a beacon highlighting anchor "impact".

For those who often do "small batch" bolt installs, many of these options are not ideal. Hilti, Powers, Simpson and Epcon all "require" the use of a crazy expensive glue gun. While that cost does spread out over time it is still a bit silly to me. Couple that with the common, LARGE mixing nozzles that are expensive ($3.50ish) and often hard to work with and the system is less than ideal for many.

After several discussion with bolters (including Jim), I've settled on Epcon A7. It's available in 10oz tubes for ~$15 which can be used with a normal and cheap caulk gun. Nozzles run $1.50 and are the PERFECT size for my typical 4in deep hole. For my typical small batch needs, this setup is GREAT. The only real downside of the A7 is it's FAST to cure. (can be an upside too). You need to have everything ready to go and glue in one fell swoop so having your system dialed is important. Hot weather and slow transitions between bolt holes can result in needing a new nozzle and much cursing. It's pretty sweet when you do it right though as you can be climbing on your glued route the same day.

It also has very low visual impact, drying to a nice grey-ish tan color.

Wave Bolt in Limestone with A7 glue

This isn't great (Hilti)

mattm wrote:I have to agree with Jim, while Hilti is a quality product it's color and extremely high costs make it a poor choice when many other, quality options are now available. In a time increased scrutiny on fixed anchors, the horrible red Hilti color is a POOR choice that acts a beacon highlighting anchor "impact". For those who often do "small batch" bolt installs, many of these options are not ideal. Hilti, Powers, Simpson and Epcon all "require" the use of a crazy expensive glue gun. While that cost does spread out over time it is still a bit silly to me. Couple that with the common, LARGE mixing nozzles that are expensive ($3.50ish) and often hard to work with and the system is less than ideal for many. After several discussion with bolters (including Jim), I've settled on Epcon A7. It's available in 10oz tubes for ~$15 which can be used with a normal and cheap caulk gun. Nozzles run $1.50 and are the PERFECT size for my typical 4in deep hole. For my typical small batch needs, this setup is GREAT. The only real downside of the A7 is it's FAST to cure. (can be an upside too). You need to have everything ready to go and glue in one fell swoop so having your system dialed is important. Hot weather and slow transitions between bolt holes can result in needing a new nozzle and much cursing. It's pretty sweet when you do it right though as you can be climbing on your glued route the same day. It also has very low visual impact, drying to a nice grey-ish tan color. This isn't great (Hilti)

Agree with you that the Hilti system is not the most ideal for rock climbers. I haven't used anything else though, so all I can say is that the expensive gun, nozzles and the size of them both is kind of annoying when you're up on the side of a tower.

As far as the colour, I don't like it one bit. When I was learning to bolt, I definitely used too much glue in more than a few holes which results in a big bright red mess. I don't really consider myself to be super experienced, only competent, and even now it's hard to keep the wall looking nice when using RE500.

One way to fix it is to carry a bag of dirt with you, and throw a handful at each freshly glued bolt. This covers the red colour nicely. Reason I didn't do that very often in Thailand was because with all of the old bolts around, it was nice to be able to tell people to "clip the one with the bright red glue!"

Ryan Williams wrote: Agree with you that the Hilti system is not the most ideal for rock climbers. I haven't used anything else though, so all I can say is that the expensive gun, nozzles and the size of them both is kind of annoying when you're up on the side of a tower."

I've come up with a glue system based on some ideas Jim has posted on his website. As I posted above, I use 10oz Tubes of Epcon A7.

I also use the smaller A24 nozzles:



Then you get a decent 10oz Caulk Gun. You want one with some form of mechanical advantage (not the really cheap ones) because the A7 takes a bit of force to pump.


You now have your somewhat short Glue Gun ready to go. Now you need to carry it.

I found a large, hard plastic cup and cut the bottom out of it. I then used a coat hanger to fashion a metal loop on the top to let me clip it to my harness (think hammer holster for a tool belt). I then found a white, plastic bag ( like you'd get from a sporting goods store) and duct taped it to the opening on the cup. Now you can stick your glue gun into the holster and the drips go down into the bag. (Props to Jim T for this setup idea). You want a WHITE bag so you can see down into the bag and view the mix color when you start a new tube. I've found that it's easy to get the hardened glue out when it dries - it doesn't really stick to the plastic.

@mountainlion:
"am looking to develop the upper pitches of the local crag"

->> would be interested to know the details. Did your efforts yield any results?

Digging up an old thread...

I am traveling to Laos at the end of the month and I'd love to bolt some new lines while I'm there. I have been developing routes in southern california with 3/8" 3" 5 piece powers bolts for some time now.

As it is totally landlocked country, all the crags are quite a ways from the ocean. Will SS powers bolts be okay to use, or is the moisture from the wetter seasons still going to degrade these bolts regardless of the distance from salt-water corrosion?

Chris Norwood wrote:Digging up an old thread... I am traveling to Laos at the end of the month and I'd love to bolt some new lines while I'm there. I have been developing routes in southern california with 3/8" 3" 5 piece powers bolts for some time now. As it is totally landlocked country, all the crags are quite a ways from the ocean. Will SS powers bolts be okay to use, or is the moisture from the wetter seasons still going to degrade these bolts regardless of the distance from salt-water corrosion?

Unfortunately the corrosion problem really isn't caused by salt water, the issue is that in a tropical environment there is a lot of vegetation which is constantly dieing. As this dead vegitation rots it produces the chlorides which cause the corrosion. When it rains these chlorides are washed down the cliff face and deposited on the bolts causing them to corrode. Basically what i'm saying is that you really should be using titanium even if you aren't near the ocean if you're in a tropical environment.

For a place such as Laos, titanium is your only responsible choice. titanclimbing.com

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When Sport Climbing first took hold, all manners of bolts were used, many of which were too weak to hold multiple falls and most of which would rust or have galvanic corrosion in a few years. This was a clear and present danger to all.

Afterwards came a period of time I'm christening the let's Replace Everything with Stainless Era, or RESE. RESE quickly became the defacto standard due of the lack of any formal or professional analysis of climbing bolt corrosion, and because it was clearly better than what we had. Because of RESE, stainless steel expansion bolts and hangers quickly populated cliffs throughout the country and the world.

These bolts, almost exclusively made of “Series 300” stainless steel, solved our problems of strength, rust and galvanic corrosion. At the time, no one knew we had only removed another layer of the onion. Few climbers had ever heard of Stress Corrosion Cracking, or SCC.

In the early 2000's P. Muraleedharan, a highly regarded metallurgist, wrote that the appearance of Stress Corrosion Cracking (SCC) in austenitic stainless steels (Series 300) in ambient conditions "depends on the patience of the observer." This was a huge divergence from previous doctrine, when metallurgists didn't think SCC could happen in temperatures under 80C (176F).

Obviously, Muraleedharan was right. RESE bolts are breaking all over the world.

Sea-side, inland, wet, dry, sandstone, limestone, basalt; it's just a matter of time. Bolts have broken in Thailand in 9 months. In Kalymnos, about 9 years.

The UIAA's upcoming corrosion guidelines will NOT approve Series 300 stainless bolts for most outdoor environments. The goal of the guidelines is that bolts should be safe for at least 50 years and many places should far exceed that.

If you look at climbing forums world-wide over the last 5 years, replacing bad stainless steel bolts is a very hot topic. And if we don't change our ways, it will continue to be a very hot topic. We need to get out of the rebolt mind-set, and get into the bolt-it-once mind-set.

The rate at which SCC proceeds in stainless climbing bolts is determined by four accelerants:

1) Higher temperatures accelerate corrosion.

2) Over time rainwater dissolves rock creating ions, and the ions are carried to the bolts in the runoff, either over the surface or by percolating through the rock (limestone & sandstone). The runoff wicks into the crevices behind bolt hangers and into bolt holes due to the capillary effect.

As the water evaporates, the ions re-combine into new compounds, which are concentrated by the “crevice effect”. The really bad ones are Magnesium Chloride, MgCl2, and Calcium Chloride, CaCl2, which are highly corrosive and promote SCC. After each cycle of rain/dry, these corrosive agents becomes more concentrated.

3) Carbonic Acid from rotting vegetation accelerates the dissolution of rock by rainwater, thus increasing the number of ions in the runoff. It also acts as a catalyst to corrosion when deposited on the bolts by rain runoff.

4) Seawater has high concentrations of dissolved Mg and Cl. Thus sea cliffs exhibit SCC most rapidly but it's wrong to think that seawater is necessary for SCC. SCC has been found far inland in Cuba, Taiwan and Okinawa. In Cuba, for example, the cliffs are 26 miles (43km) from the sea.

The above factors explain things like why tropical areas are worse than temperate areas; why sea cliffs are worse than inland cliffs; why glue-ins (no crevices) last longer than expansion bolts; why the bolts at the bottom of the cliff are worse (the runoff has longer to collect ions and unfortunately low bolts also see the highest fall factors), why limestone is worse than granite, and why no one's yet seen SCC in alpine (too cold) or desert (too dry)  environments.

Thanks for the detailed responses guys. Well I wont be bringing any SS then, as I don't want to leave a legacy that will be unsafe in a few years. Does someone know if there is anywhere in Thailand (or SE asia?) that I would be able to get my hands on any titanium bolts?

I won't be able to get any around here before I leave to Laos, but I may still throw in my hand-drill and hooks in the pack.

Chris Norwood wrote:Thanks for the detailed responses guys. Well I wont be bringing any SS then, as I don't want to leave a legacy that will be unsafe in a few years. Does someone know if there is anywhere in Thailand (or SE asia?) that I would be able to get my hands on any titanium bolts? I won't be able to get any around here before I leave to Laos, but I may still throw in my hand-drill and hooks in the pack.

Contact Martin at titanclimbing.com to order Ti bolts. Have him ship them to your destination in Laos. Since he's the world's only supplier of Ti bolts, he may also be able to tell you if there's anyone in Laos you may be able to purchase them from.

Good luck.

P.S. He also sells 14mm SDS bits and hole brushes which he can ship with your order.

John Byrnes wrote: Since he's the world's only supplier of Ti bolts,

He is not the world's only suppler of titanium bolts. There was a company on eBay selling titanium bolts and hangers awhile back. Also, it's not hard to get your own bolts made either. United Titanium has made climbing bolts on multiple occasions.

20 kN wrote: He is not the world's only suppler of titanium bolts. There was a company on eBay selling titanium bolts and hangers awhile back. Also, it's not hard to get your own bolts made either. United Titanium has made climbing bolts on multiple occasions.

I'm quite familiar with United Titanium, as one of the group who ordered bolts from UT back in 2011, the only time (not multiple occasions) they made bolts. The Thaitanium Project specified the bolts based on our old Tortuga design. UT has a 1,000 pcs minimum, which means you need to come up with about $12,000 up front. Testing was done independently. Doing this is a PITA compared with ordering from an actual supplier. I'm still amazed at the amount of work Josh had to do to provide us with bolts.

The Chinese company on Ebay, "Keith", is offering Ti expansion bolts at $40ea, 3 times the going rate. Keith specifies their strength to four digits which is certainly bullshit. You're an engineer, right?, so you know why. The sleeve on the bolt looks to be only an inch inside the rock and the entire bolt maybe 2" long (might be okay in perfect granite). I'd be ashamed to place these bolts on a route and terrified to climb a route with them.

So for all practical purposes, Martin is the only supplier of Certified Titanium climbing bolts.

John Byrnes wrote: So for all practical purposes, Martin is the only supplier of Certified Titanium climbing bolts.

You had mentioned in the post(couple of years back, though) that you knew of a process in which to create titanium bolts for ~$4 each. Do you still have this knowledge, and are you up for sharing this knowledge? If nothing else it would be good to learn some new things.

Eliot Augusto wrote: You had mentioned in the post(couple of years back, though) that you knew of a process in which to create titanium bolts for ~$4 each. Do you still have this knowledge, and are you up for sharing this knowledge? If nothing else it would be good to learn some new things.

Your memory is good. A good friend of mine, a climber, professional metallurgist, and whose day-job is producing titanium parts for aerospace, estimated a investment casted (Google it) Grade 5 Ti bolt would cost about $4.

Subsequently, Grade 2 Ti (not Grade 5) was determined to be best for climbing bolts since it's plenty strong and has the best corrosion resistance in the conditions in which climbing bolts are placed. I don't know if Grade 2 can be investment casted in the same manner as Grade 5, but I know of no reason it can't.

My other impression I took away is that investment casting requires a higher capitalization than forging (the process used today), which means the climbing community as a whole would need to buy a lot more Ti bolts than it does currently. This may still happen. This should happen.

Ultimately, like every new technology, Ti bolts as a product, will mature out of infancy and become mainstream. When the volumes become large enough to incite multiple suppliers in competition, then the prices will come down.

John Byrnes wrote: Your memory is good. A good friend of mine, a climber, professional metallurgist, and whose day-job is producing titanium parts for aerospace, estimated a investment casted (Google it) Grade 5 Ti bolt would cost about $4. Subsequently, Grade 2 Ti (not Grade 5) was determined to be best for climbing bolts since it's plenty strong and has the best corrosion resistance in the conditions in which climbing bolts are placed. I don't know if Grade 2 can be investment casted in the same manner as Grade 5, but I know of no reason it can't. My other impression I took away is that investment casting requires a higher capitalization than forging (the process used today), which means the climbing community as a whole would need to buy a lot more Ti bolts than it does currently. This may still happen. This should happen. Ultimately, like every new technology, Ti bolts as a product, will mature out of infancy and become mainstream. When the volumes become large enough to incite multiple suppliers in competition, then the prices will come down.

Sure, the $4 would cover the cost of the metal but not the tooling, process costs and all the rest. About $15 would be a commercially interesting retail price if the market was large enough, a 316 bolt costs about $3. A mid-sized climbing equipment manufacturer would want to see a market of 10,000 units to make it worth the hassle of starting up which clearly none of us see as reasonable at the moment.