Glue Question

C.Williams wrote: For sure! I was thinking one vertical with a second below horizontally positioned and chain connecting to a large ss link on the lower u bolt. Hope that makes sense.

That's fine. Where are you finding 316 U bolts?

Local fastener supplier. They specialize in marine grade fasteners and offer 10mm stock u-bolts. 115mm legs with 90mm spacing. About $5 a piece.

Avoid u-bolts on softer rock. For limestone or less the recommendation is to drill bolt placements 8" or more apart.

If you're drilling into granite then u-bolts certainly work.

TheIceManCometh wrote:Avoid u-bolts on softer rock. For limestone or less the recommendation is to drill bolt placements 8" or more apart. If you're drilling into granite then u-bolts certainly work.

I don't agree with this at all. It's possibly a good rule-of-thumb for expansion bolts in bad rock, but not with glue-ins.

For example, Titanium U-bolts have been used for decades in Thai limestone and are still bomber.

If the rock is laced with fractures, a.k.a. choss, then perhaps I can see this. But for monolithic limestone or sandstone, it's overkill IMO.

TheIceManCometh wrote:Avoid u-bolts on softer rock. For limestone or less the recommendation is to drill bolt placements 8" or more apart.

I don't believe that the chain sets offered by Fixe or Raumer have the bolt hole distances at 8" (I use them all the time...I guess I need to measure). See Fixe Tradition Anchors.

Where does this 8" recommendation come from and why?

Brian in SLC wrote: I don't believe that the chain sets offered by Fixe or Raumer have the bolt hole distances at 8" (I use them all the time...I guess I need to measure). See Fixe Tradition Anchors. Where does this 8" recommendation come from and why?

Twice the bolt length apart is the normal rule, we make our chainsets spaced 208mm (8") but that is really just because of the chain link length. It´s all kind-of theoretical because a) the spacing rules are for concrete which normally fails different to rock and b) the way construction bolts generally fail is different to the way most climbing bolts fail.
The theory says bolt failure will occur as a cone starting from the base of the bolt (or the point of loading for a bolt-in) but that is because concrete is relatively weak and fails through the matrix, most glued climbing bolts fail as they progressively stretch and the cone of fracture is much smaller, normally about 1/3rd down the bolt, then comes another smaller cone then glue failure.
Others, especially the older Fixe bolt just fail at the glue anyway without any noticeable fracture cone and the same goes for almost all bolts in hard granite.
In reality the rule is for axial failure with both bolts equally loaded which in our application (including staples) is virtually unheard of since the loads would be unbelievably high. Staples always fail one leg first in all the tests I´ve seen or done, they are still a fairly shit design because on non-overhanging routes the karabiner slides in and contacts the rock making gate-open failure likely, the Fixe ones have a pronounced dropped nose for this reason. Getting good glue contact is also extremely difficult as you can´t twist the bolt in and most tests show erratic resin coverage on the threads.

Incidentally some people still blindly follow the spacing rule when they re-bolt with glue-ins, since only one bolt is going to be loaded this is incorrect and in fact with glue-in replacements it is perfectly aceptable to place the new bolt touching the old one though to be on the safe side I normally install one slightly longer than the original bolt.

Jim Titt wrote: Twice the bolt length apart is the normal rule, we make our chainsets spaced 208mm (8") but that is really just because of the chain link length. It´s all kind-of theoretical because a) the spacing rules are for concrete which normally fails different to rock and b) the way construction bolts generally fail is different to the way most climbing bolts fail. The theory says bolt failure will occur as a cone starting from the base of the bolt (or the point of loading for a bolt-in) but that is because concrete is relatively weak and fails through the matrix, most glued climbing bolts fail as they progressively stretch and the cone of fracture is much smaller, normally about 1/3rd down the bolt, then comes another smaller cone then glue failure. Others, especially the older Fixe bolt just fail at the glue anyway without any noticeable fracture cone and the same goes for almost all bolts in hard granite. In reality the rule is for axial failure with both bolts equally loaded which in our application (including staples) is virtually unheard of since the loads would be unbelievably high. Staples always fail one leg first in all the tests I´ve seen or done, they are still a fairly shit design because on non-overhanging routes the karabiner slides in and contacts the rock making gate-open failure likely, the Fixe ones have a pronounced dropped nose for this reason. Getting good glue contact is also extremely difficult as you can´t twist the bolt in and most tests show erratic resin coverage on the threads. Incidentally some people still blindly follow the spacing rule when they re-bolt with glue-ins, since only one bolt is going to be loaded this is incorrect and in fact with glue-in replacements it is perfectly aceptable to place the new bolt touching the old one though to be on the safe side I normally install one slightly longer than the original bolt.

Excellent information. Thanks Jim.

In construction it is common to cut lengths of all-thread to make epoxy bolt placements. Seems to me this would be fine for rock too. SS 3/8" or 1/2" would be easy to cut and glue. Is there some concern with it unthreading ? the threads could be beaten, cut or ground a bit.

C.Williams wrote:We are getting ready to replace one of our local crags with glueins due to softer rock and high traffic. Typically I would use Powers AC100 but I am questioning my choice due to the wild temperature swings this wall experiences. The wall is south facing and sees rock temperatures over 100 in the summer and -30 in the winter. Will my current glue choice handle this or is there a better option? Are glueins even suitable in this situation?

There's a kept-quiet/access-sensitive crag near me with glue-in bolts. The rock is basalt/traprock. No idea how old the bolts are, or even if they're in need of replacement. How do you know when to replace, how long should you go before replacing them, and how do you remove them?

Jim Titt wrote: Twice the bolt length apart is the normal rule, we make our chainsets spaced 208mm (8") but that is really just because of the chain link length. It´s all kind-of theoretical...

I've used this "cone of weakness" concept for years based on the recommendations of the concrete fastener guys. I've always related the minimum distance to fastener length. Good stuff!

I'd be just curious where the iceman is coming from for "limestone or less" and if there's any info/data out there to support that recommendation.

A number of years ago, was a bolt failure at Cave Creek in Arkansas. Got to snap a pic of the result:



Sandstone. As I recall, took the climber that fell by surprise (!)...

Thanks!

geoff georges wrote:In construction it is common to cut lengths of all-thread to make epoxy bolt placements. Seems to me this would be fine for rock too. SS 3/8" or 1/2" would be easy to cut and glue. Is there some concern with it unthreading ? the threads could be beaten, cut or ground a bit.

Mostly the problem is hardware store threaded stainless rod is unbelievably weak! 3/8" you´d be lucky to see 8kN (I can´t be more definate as we only have metric sizes here). Then you need a hanger and washer/nut so you are approaching the cost of a proper glue-in bolt.
The other hassle is glue "creeps", under continous load the bolt slowly becomes loose and at the tension you need to apply to stop the hanger moving this is a real problem.
Use big enough threaded bar, angle cut the end so it can´t turn and you have developed an expensive solution to something which isn´t a problem, has all the corrosion problems associated with mecahnical bolts and still have crappy karabiner-destroying hangers!

Michael C wrote: There's a kept-quiet/access-sensitive crag near me with glue-in bolts. The rock is basalt/traprock. No idea how old the bolts are, or even if they're in need of replacement. How do you know when to replace, how long should you go before replacing them, and how do you remove them?

Put a pull tester on them. Otherwise give them a tweak with an 18" wrecking bar and see what happens (but don´t go mad). The first option is the better one!

Michael C wrote: There's a kept-quiet/access-sensitive crag near me with glue-in bolts. The rock is basalt/traprock. No idea how old the bolts are, or even if they're in need of replacement. How do you know when to replace, how long should you go before replacing them, and how do you remove them?

The wall I was speaking of is being upgraded to gluein bolts. My understanding is adhesive anchors need very little maintenance unless installed poorly.

Michael C wrote: There's a kept-quiet/access-sensitive crag near me with glue-in bolts. The rock is basalt/traprock. No idea how old the bolts are, or even if they're in need of replacement. How do you know when to replace, how long should you go before replacing them, and how do you remove them?

Micheal,
Top rope anchors, that do not move & show little signs of wear;
Those bolts are fine (as of 8/16 )

they are less than Ten Y'Rs old.

Free Watchung
(free the Pallisades !)

it is also time to get climbing in NJ open & legal.

The county freeholders need to be protected from potential legal action, of injured
By a waiver system.

The parking for the rock at seeley's pond, (now has No Climbing signage??!!!)

The place has been a climbing area for at least 60 Y'Rs! Once known & called Watchung (for the last 40 years) It should & can be an open to climb zone (With out fear of situation) if the climbing gym lobby wants it opened.

How did the Pine Paddies work out?

What is the best glue for reinforcing a hold? Something with low viscosity?

The wall we are replacing is covered in Hilti RE500. It really locks the shaky holds down but looks ugly and really sucks to grab if it gets onto the hold. I have used Powers AC100+ on a few holds. Still strong and super low visual impact. It has some texture when cured too.

Can you comment on viscosity? In this case the glue would not get on the hold itself and would be nearly invisible, but I need it to seep down in a thin crack behind the hold. The hold feels solid as it is, but it is a razor blade crimp separated from the wall by an 1/8" gap. If it does come off the pitch will become impossible.

Michael Schneider wrote: Micheal, Top rope anchors, that do not move & show little signs of wear; Those bolts are fine (as of 8/16 ) they are less than Ten Y'Rs old...How did the Pine Paddies work out?

Hey Michael, had no idea there were signs up in the lot. I took my son there a few weeks ago for his first day outside and we went ahead and crossed the creek since it was low.

Haven't been up to the Pine Paddies, yet. Thinking of going in the late winter/early spring, when vegetation will be at a minimal. Been Gunkin' and Linze'n it otherwise.

I wouldn't call either epoxy "drippy". The RE500 has a lower viscosity for sure though I would bet either will inject easily into the space behind the hold. I have reinforced a few holds this way with good success. Some of the cheaper climbers in my area have used hardware store epoxy, which is almost runny, but the success seems variable.

C.Williams wrote:The wall we are replacing is covered in Hilti RE500. It really locks the shaky holds down but looks ugly and really sucks to grab if it gets onto the hold. I have used Powers AC100+ on a few holds. Still strong and super low visual impact. It has some texture when cured too.

I've used RE500 to reinforce holds a number of times, but only a few times in a situation where the climber could actually touch the glue. But in all cases, I put local sand on the glue while it was still wet.

Since you want to force the glue into the crack you want to stabilize, pour the sand on thickly (so your fingers don't touch the glue), and press down on it. This will force the glue into the crack, AND force a lot of sand into the glue to a depth that it won't just brush off with use.

The sand also camouflages the glue if the color (dusty rose) doesn't match your local rock. (You know that RE500 doesn't stay "hot pink" but ages to "dusty rose"?)