Two Recent Glue In failures; are there others?

Rob Warden...Space Lizard wrote:

How recent was this sunny and steep failure? Those eye bolts are like 5/8s. I can go out a wave bolt there later. 

Not sure, I think it was a while ago, my buddy who relayed the information to me has been climbing in Red Rock for over 30 years.  We were talking about bolting in general and he gave that as an example of his dissatisfaction with glue-in anchors.  The time frame of the replacement wasn't germane to the conversation, so I won't even guess.

when we place glue-ins in a commercial setting(I'm a comm. GC for 20+ yrs) we're required to have a certified 3rd party inspector watch the process. We pre-drill the holes then the inspector shows up and we check every hole for depth/cleanliness(they watch you blow air in every hole, then scrub with wire brush, then more air and repeat til theres no visible dust exiting the hole), then they watch you apply the spec'd adhesive(typ. SET-22) and set the bolt with a few twists, making sure that there is glue oozing out of the hole after setting, to get a full depth bond . ...occasionally they will come back and do a pull and torque test a few days later....and yet they still fail sometimes after all that ...   . 

Rob Warden...Space Lizard wrote:

How recent was this sunny and steep failure? Those eye bolts are like 5/8s. I can go out a wave bolt there later. 

To add a bit more to the timeline, the five piece has been in that hole since I moved here in 2005, so failure was before that.  I read your comment too quickly and missed your offer to fix it.

I could t read all of this to know I it's been mentioned, excuse me. Seems Hilti glue was mentioned. Does anyone use Simpson brand epoxy? Comes in a double bottle with mixing tube. 

BigB wrote:

when we place glue-ins in a commercial setting(I'm a comm. GC for 20+ yrs) we're required to have a certified 3rd party inspector watch the process. We pre-drill the holes then the inspector shows up and we check every hole for depth/cleanliness(they watch you blow air in every hole, then scrub with wire brush, then more air and repeat til theres no visible dust exiting the hole), then they watch you apply the spec'd adhesive(typ. SET-22) and set the bolt with a few twists, making sure that there is glue oozing out of the hole after setting, to get a full depth bond . ...occasionally they will come back and do a pull and torque test a few days later....and yet they still fail sometimes after all that ...   . 

this has been basically my experience as well, emphasizing the "they still sometimes fail after all that" part.

Jim Titt wrote:

Glue-ins are far superior in most respects...

i find this to be purely an opinion and one that i don't really agree with....

BigB wrote:

occasionally they will come back and do a pull and torque test a few days later....and yet they still fail sometimes after all that ...   . 

What fails? And I assume the epoxy cured properly? That's interesting as I've never heard of properly cured, properly installed epoxy failing under any circumstance, except in one case with a recalled batch of the stuff.

For what it's worth, I've seen mechanical anchors fail to work in concrete many times as well, even 3/4" wedge bolts. For some reason drivers seem like to hit light poles and guard rails around here often. Those fixtures are typically installed in with 5/8" - 1" glue-in threaded rod or wedge bolts. On several occasions I've seen a fixture struck by a car and the wedge bolts did not shear off, but rather they pulled up and out of the concrete which showed that the expansion clip did not engage properly for some reason and the bolt just slid out. I've seen this happen around 10 times over the years.

Joe Garibay wrote:

Does anyone use Simpson brand epoxy?

Yep, lots of people. I've used it many times.

20 kN wrote:

What fails? And I assume the epoxy cured properly? That's interesting as I've never heard of properly cured, properly installed epoxy failing under any circumstance, except in one case with a recalled batch of the stuff.

For what it's worth, I've seen mechanical anchors fail to work in concrete many times as well, even 3/4" wedge bolts. For some reason drivers seem like to hit light poles and guard rails around here often. Those fixtures are typically installed in with 5/8" - 1" glue-in threaded rod or wedge bolts. On several occasions I've seen a fixture struck by a car and the wedge bolts did not shear off, but rather they pulled up and out of the concrete which showed that the expansion clip did not engage properly for some reason and the bolt just slid out. I've seen this happen around 10 times over the years.

Id say more often than not,  its the actual bonding to the concrete. Theories being that the concrete was not porous enough to allow the bond*, or that you just didn't get it clean enough(inspectors generally will say: bulb blowers are not adequate, compressed air in cans is barely sufficient but frowned on, air compressor is ideal, always blow, brush, blow, brush then blow again, and sometimes that's still not clean enough)   

* it seems like the drill bit actually glazes the concrete surface inside the hole, due to improper drill bit speed ..ie... too fast

slim wrote:

i find this to be purely an opinion and one that i don't really agree with....

BigB wrote:

Id say more often than not,  its the actual bonding to the concrete. Theories being that the concrete was not porous enough to allow the bond*, or that you just didn't get it clean enough(inspectors generally will say: bulb blowers are not adequate, compressed air in cans is barely sufficient but frowned on, air compressor is ideal, always blow, brush, blow, brush then blow again, and sometimes that's still not clean enough)   

* it seems like the drill bit actually glazes the concrete surface inside the hole, due to improper drill bit speed ..ie... too fast

Choosing a different epoxy could solve that issue. RE-500 is known to bond to the base material extremely well. I recall a test awhile back where a nut was filled with epoxy and then stuck to the surface of concrete. RE-500's bond was strong enough that when they twisted the nut off with a wrench it broke the concrete. Other epoxies just failed at the bond. RE-500 is great, it's just not worth the price considering it's an astronomical five times more expensive than other products with similar specifications.

J. Albers wrote:

I completely agree. A glue-in installed by a competent and careful individual is great and in many instances the ideal bolt situation. However, in the hands of many bolters, the potential for catastrophic bolt failure due to inept execution seems real and very concerning. When I first started climbing I assumed (naively) that bolt installers knew what they were doing. After having the opportunity to meet many route equippers over my almost two decades of climbing I have come to realization that many equippers are a few beers short of a sixer. My conclusion is that one of the only things stopping more time bombs is the fact that most mechanical bolts (sleeves/wedge/etc) have enough tolerance to idiocy built into their design that bolt failure is rare. If you read posts like Mr. Haden's and 20Kn's above for example, it becomes quite clear that installing glue-ins has way, waaay more opportunity for failure due to lack of knowledge or idiocy involved. It should certainly be of concern to the community in my opinion. 

Very much so.

Whilst training can be provided by an adhesive retailer e.g. Hilti provide training on their resin bonded anchor products,  there is another level of awareness on top since our adopted use of resin bonded anchors is very specific, with no to little capacity for improperly installed fixings. Additional checks need to be incorporated into dispensing procedures to catch issues such as those discussed in this thread and these will not be seen conducted on construction sites (where there is no value to do so).

Training is the key (as with anything) and for anything bolting related, either you luck upon a competent mentor or have to gradually figure it out along the way and that is not ideal.

20 kN wrote:

Choosing a different epoxy could solve that issue. RE-500 is known to bond to the base material extremely well. I recall a test awhile back where a nut was filled with epoxy and then stuck to the surface of concrete. RE-500's bond was strong enough that when they twisted the nut off with a wrench it broke the concrete. Other epoxies just failed at the bond. RE-500 is great, it's just not worth the price considering it's an astronomical five times more expensive than other products with similar specifications.

RE500 is expensive in the UK too, although eBay often has new unbroken packs at reasonable prices. For some reason it's reasonably priced in Asia. Typically we'll buy an entire box of 500ml packs as a group since it's cheaper then take the 1or 3 packs etc individually pledged for from the total.

Most private users of Hilti products I know latch onto a friend in the construction industry and leverage trade discounts to offset the higher walk-in-off-the-street pricing. Not an option for everyone granted.

Given the intended design life for industrial adhesives, it is going to take considerable time before the bolting community discovers which adhesives last. There remains significant discussion around material type when the choices are really quite obvious however adhesives on the other hand are far more complicated given the lack of information many manufacturers provide on their products but more over, the time we need in order to ascertain suitability. Climbers have not been using resin bonded anchors for much more than 30 years* and the current design focus is on achieving at least 50 years safe and reliable use.

*Disclaimer* Global, widespread use with the type of products discussed in this thread, before Jim provides a history lesson to the young un here! ;-)

BigB wrote:

Id say more often than not,  its the actual bonding to the concrete. Theories being that the concrete was not porous enough to allow the bond*, or that you just didn't get it clean enough(inspectors generally will say: bulb blowers are not adequate, compressed air in cans is barely sufficient but frowned on, air compressor is ideal, always blow, brush, blow, brush then blow again, and sometimes that's still not clean enough)   

* it seems like the drill bit actually glazes the concrete surface inside the hole, due to improper drill bit speed ..ie... too fast

It´s a bit yes and no really, the difference between the holding power in holes drilled with a compressed air drill (as in mining or tunnels etc) and a rotary hammer drill and a simple hammer drill is considerable, even more if you include diamond drilled holes (there´s a technical document on the different strengths somewhere on one of the manufacturers websites). We´ve also noticed that using a higher speed drill with a finer hammer action gives worse results than a slow "thumper" like an old Bosch Bulldog.

Air cans are frowned on as they are likely to run out before the hole is properly cleaned and the operator says "hell that´ll do" rather than fetching another but more importantly may well have been filled from an oil-lubricated compressor, oil-less ones being somewhat of a rarity.

Basically the rougher the hole the better the mechanical engagement and the bonding becomes less and less important, learning to use the drill bit to enlarge the hole slightly after about half the depth is the way to achieve good holding power irrespective of the actual adhesive bond. As the standard for climbing bolts says the resistance to extraction must be solely mechanical we don´t even consider bond strength when designing a bolt, only the shear strength of the morter. The bond strength onto a dirty piece of stainless covered in somebodies greasy sweat is anyway zero! 

The best results are always achieved using spin-in glass capsules, the grinding action of the glass particles and the quartz crystals combined with the liquid resin giving the best bond both to the rock and the bolt itself. Unfortunately the capsules come in a limited range of sizes limiting the choice of bolt, the bolt must be specially made to function properly and installation can be a bit more complicated. The availability and price in the USA is also a hassle.

20 kN wrote:

Choosing a different epoxy could solve that issue. RE-500 is known to bond to the base material extremely well. I recall a test awhile back where a nut was filled with epoxy and then stuck to the surface of concrete. RE-500's bond was strong enough that when they twisted the nut off with a wrench it broke the concrete. Other epoxies just failed at the bond. RE-500 is great, it's just not worth the price considering it's an astronomical five times more expensive than other products with similar specifications.

You are probably correct....however we  have to use what was spec'd by engineer/architect...or do a submittal for eq. or better and, that doesn't always go so easy :(

newrivermike wrote:

We've had 2 glue-in "failures" at the NRG. Both were identified as loose and fixed or removed before anyone fell on them. One, on Quinsana was identified within a few days. The other was there for 5+ years before it was identified and removed. Both these bolts were placed during the same time period by the same experienced person. They were placed properly in good rock. We believe the glue was the problem. The bolter used glass capsules. I believe they were made by Hilti...? I can't find a link to them anymore but they were a glass capsule that you'd push into the hole, then hammer the bolt in over it. The glass would break and you'd spin the bolt to mix the glue. We haven't used these since that one batch we had way back then, but if anyone has used this product, it's worth knowing about. 

What was the second route with the glue-in failure, if you don't mind me asking?

The glass ampules looked like a great idea on the surface. It solved the a lot of the mess and the "how much glue" and "how to mix" questions as long as you stuck with the system and didn't go off making yer own wave bolts or some such. The problem with the Glass capsules for climbers and why I didn't want to trust them was this: WHAT THE F*** IS THE EXPIRATION DATE???!!!! All the other packaging options (cartridges, packs etc) have an expiration date stamped on it. The glass capsules do not. Sooo, lets say dirtbag climber A finds some on Ebay left over from a large construction project. This is a common occurrence that parts like this are over ordered on a multi million $ project so that there are extras - or in fact there may be a design change or the project gets scuttled and none of them get used. As far as that goes,  say climber A buys a few and never does his project. Sells to climber B, whats the expiration date? How were they stored? Fellas trunk in the summer? Basement? etc etc? The glass capsule glue will turn to dust, I've personally seen this happen to Petzl product where it hardens inside the capsules. In between where it is hard and where it is brand new is a continuum of sorts, where it will not be good to use. What is that point? No one here knows. I certainly don't. So that was the issue with the glass ampules full of glue that Petzl use to peddle to climbers and it was a HUGE problemo for climbers in my view. Maybe not an issue at all for a commerical project where the mfg tracking numbers and dates follow the product. 

Joe Garibay wrote:

I could t read all of this to know I it's been mentioned, excuse me. Seems Hilti glue was mentioned. Does anyone use Simpson brand epoxy? Comes in a double bottle with mixing tube. 

That's because Hilti makes fantastic product. Simpson SET Strong Tie 2 part epoxy also meets all the building specs and is good product for climbing applications. However, as someone else noted upthread - make sure the expiration dates have not passed. https://www.strongtie.com/epoxyanchoringadhesives_adhesives/set_adhesive/p/set

Billcoe wrote:

The glass ampules looked like a great idea on the surface. It solved the a lot of the mess and the "how much glue" and "how to mix" questions as long as you stuck with the system and didn't go off making yer own wave bolts or some such. The problem with the Glass capsules for climbers and why I didn't want to trust them was this: WHAT THE F*** IS THE EXPIRATION DATE???!!!! All the other packaging options (cartridges, packs etc) have an expiration date stamped on it. The glass capsules do not. Sooo, lets say dirtbag climber A finds some on Ebay left over from a large construction project. This is a common occurrence that parts like this are over ordered on a multi million $ project so that there are extras - or in fact there may be a design change or the project gets scuttled and none of them get used. As far as that goes,  say climber A buys a few and never does his project. Sells to climber B, whats the expiration date? How were they stored? Fellas trunk in the summer? Basement? etc etc? The glass capsule glue will turn to dust, I've personally seen this happen to Petzl product where it hardens inside the capsules. In between where it is hard and where it is brand new is a continuum of sorts, where it will not be good to use. What is that point? No one here knows. I certainly don't. So that was the issue with the glass ampules full of glue that Petzl use to peddle to climbers and it was a HUGE problemo for climbers in my view. Maybe not an issue at all for a commerical project where the mfg tracking numbers and dates follow the product. 

Glass capsules don´t have an expiry date as there isn´t one,  the two components are completely sealed in glass and are considered inert if stored under normal circumstances. The test to check something untoward hasn´t happened is to invert the capsule and see if the resin is still liquid.

The most common problems with capsules is the bolts need a different end form than the usual chisel point to mix the components correctly and most importantly the length must match the hole depth otherwise you just stir the resin around and the hardener stays down the bottom. If you buy a compatible system glass capsules are excellent.

You do also have to know that there are various systems used industrially and a "spin to stall" capsule won´t work the way we install bolts. Drive in capsules however do so long as the bolt is of the correct form.

It would explain Newrivermikes comment and suspicions that glue was the problem concerning the New River Gorge bolt failures:

"We've had 2 glue-in "failures" at the NRG. Both were identified as loose and fixed or removed before anyone fell on them. One, on Quinsana was identified within a few days. The other was there for 5+ years before it was identified and removed. Both these bolts were placed during the same time period by the same experienced person. They were placed properly in good rock. We believe the glue was the problem. The bolter used glass capsules. I believe they were made by Hilti...? I can't find a link to them anymore but they were a glass capsule that you'd push into the hole, then hammer the bolt in over it. The glass would break and you'd spin the bolt to mix the glue. We haven't used these since that one batch we had way back then, but if anyone has used this product, it's worth knowing about. "