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Installation of "hammer-in" glue-in bolts, have you done it?

Original Post
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392

I'm looking for discussion with others who have placed glue-in bolts, especially of the "hammer-in" type, such as the Wavebolt and twisted-leg bolts. I have placed about 400 glue-in bolts; all have been of the single-stem type pictured below.

A titanium glue in bolt
So let me set the stage. My questions come near the end.

After injecting the Right-Amount-of-Glue, RAG, (more on that later) into the hole, I insert the bolt into the hole until I feel it contact the glue. Then I spin the bolt as I continue to push, coating the stem with glue. When I have about 3/8" to go, I orient the bolt and push it in the rest of the way.

A healthy amount of glue should mushroom out which is sculpted with a wooden stick into a smooth fillet. Excess is cleaned up with the stick and rag.

The fillet is important in that there are no crevices where water, and its corrosive ions, can wick in by capillary action. Crevice corrosion is one of the main reasons expansion bolts corrode and fail, and we should do our best to minimize crevices in our glue-in placements too. A nice fillet looks good too, which gives climbers confidence. Remember the thread about the Anarchy wall bolt?

Now, as anyone who's placed a glue-in knows, getting the RAG into the hole is a black-art. Too little and the strength of the placement is in doubt and a void at the surface is a perfect spot for corrosion to start. Too much is a waste of expensive glue and requires a clean-up effort.

Complicating the problem is the existence of small voids within the rock (some limestone is like Swiss cheese) that need to be filled with glue. When I've encountered this, I've pulled the bolt out, injected more glue, and re-inserted the bolt. Sometimes it takes several iterations, or a new hole, before I get a good mushrooming of glue. But it's almost impossible to get a hammer-in bolt back out, even with a funkness device.

So finally I get to my questions... Recently I've seen several routes with hammer-in-glue-in bolts where the glue job was ugly. Not only were there gaps/crevices at the surface but glue was all over the bolt and rock.

My understanding is that the glue spurts out with each hammer blow. The installer then has to, or maybe not, try to inject glue into the gaps once the bolt is fully seated and oriented. One installer told me he puts glue into the hole on both sides of the bolt incrementally as he hammers. I.e. glue-hammer-glue-hammer-glue... while the glue hardens in the nozzle.

So I'd like to hear from people who have placed bolts of this type. How do you ensure the bolt is well-encased with glue? If possible, how do you avoid voids in the glue (deep in the hole) and crevices at the surface? How do you keep the glue from ejaculating, and if you can't, how do you keep it from ending up all over the place? If you don't get enough glue into the hole (voids) how do you get the bolt out? Other pearls of wisdom appreciated too ;-)

JohnWesely Wesely · · Lander · Joined Nov 2009 · Points: 585

I don't get any more "ejaculation" when I hammer than when I don't.

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

Normally you would have noticed if there is a hole or pocket in the rock when you´re drilling and made a note to add more glue. You can feel the injected resin pushing the gun back out of the hole anyway if you have a delicate touch.
My bolts (Bolt Products Twisted Leg Bolts) only require a tap for the last part, you don´t "hammer" them in, in fact you can´t as they will jam up. You don´t need any special tools and glue doesn´t spurt everywhere.
If you were a bit economical with the glue you should normally be able to see this before you tap them home as only the last piece is an interference fit, normally if it isn´t much resin missing I´d inject in either side to seal the hole. If clearly there is a lot missing then I take the bolt back out and fill again. If this still doesn´t work because the hole has a huge void then I´d normally drill again or deep drill and fit a longer bolt.
The excess resin I remove (and produce the fillet) using my finger and clean this either on the back of the work glove I wear on my left hand or my trousers depending.

Sam Lightner, Jr. · · Lander, WY · Joined Apr 2006 · Points: 2,732

If you fill the hole almost to the outer edge the glue will find the spots it should be in. It will go there before it comes out.

The contact with the rock is a flaw we must live with in this design. No way around it as that contact is what holds it in. I prefer regular glueins, because they will likely last longer due to no contact with the rock, when I'm in a vertical plain. For overhanging placements the wave and twist legs are the best.

I often angle the bit up and run it for a second just after drilling to depth. I let the tip hit about 1/3 of the way into the hole. This makes a notch in the top of the shaft. It is no longer a perfect tube. Now the glue not only adheres to the wall, but is also actually wider on the inside than on the outside making it mechanical.

If you carry a bag of dirt up with you, and throw that dirt at the glue after you have placed the bolt, it hides the glue very well. Thats what I do.

Wave Bolts are great, but so are Jims. You can't go wrong with either, but Jims take less force to go into the hole (the counter meaning that wave bolts hold better without the glue hardened.

Sam Lightner, Jr. · · Lander, WY · Joined Apr 2006 · Points: 2,732
Morgan Patterson · · NH · Joined Oct 2009 · Points: 8,945

A hammer in glue-in... as if...lol.

So John, you've provided some great reasons why the Wave bolt is a great hammer in glue-in bolt.

But as someone who has also placed glueins I'm left scratching my head about the advantage of a hammer in glue-in vs just drilling the hole an 1/8 or 1/16th bigger and just sliding it in without hammering it? I'm also thinking as your bit wears you going to have a smaller hole and more hammering and a significantly more difficult bolt to actually remove if someone smashes it or it needs to be replaced.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392

John,

Thanks for the info. Yours is the type of information I'm looking for.

You said you use a tool over the bolt to hammer. Is it a specialized tool or could it be used for other brands of hammer-ins? Can you describe it?

You say you're "tapping" in the bolt. What size hole are you drilling? I've heard several people say they had to hammer hard. I thought Wavebolts were supposed to hold body-weight without glue, so it amazes me you can twist them by hand...??

How do you smooth the glue once the bolt is fully seated?

This winter I'll be, for the first time, using a two-legged bolt that has a "light-interference fit" to hold it in place. The two legs spread slightly for the last 1/2" before the eye and so should fit snug in the hole with a few taps of a hammer.

I didn't think these would be much of a departure from what I've been doing, but then I saw quite a few ugly placements by several different installers, and thought I should try to learn something before I try it myself. Uncommon, I know.

Morgan Patterson · · NH · Joined Oct 2009 · Points: 8,945

Ah... overhangs I guess would be one.

And Sam - thanks for the pointer on deforming the inside of the hole a bit to make a the bolt work mechanical as well. Awesome idea man!

Greg Barnes · · Unknown Hometown · Joined Apr 2006 · Points: 2,060

Morgan, the idea is that you can use them on overhangs, roofs, etc without worrying about the bolt sliding out.

The "Wave bolt tool" is a specialized tool that Climbtech makes. It does not fit Jim's bolts.

I've only placed a couple in a test rock (granite), but I had to hammer nice and hard and certainly couldn't twist it. I had to funk it to remove it (testing that one without glue of course!), not nearly as hard as funking a piton, but it did take a good amount of force. John is replacing on soft Calico Hills sandstone at Red Rocks, so the holes will be bigger and it'll be easier to move the bolts.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
Jim Titt wrote:Normally you would have noticed if there is a hole or pocket in the rock when you´re drilling and made a note to add more glue. You can feel the injected resin pushing the gun back out of the hole anyway if you have a delicate touch.
I used to think I could feel voids while drilling too, but after hundreds of holes, I've concluded I can't, at least not in Cayman limestone. Sometimes the void is near the surface, so you don't get any hydraulic push-back in the gun. I think it depends on the rock. I'm pretty sure Thailand is the same way. And as you say, sometimes I abandon a hole and drill a new one.

Jim Titt wrote:The excess resin I remove (and produce the fillet) using my finger and clean this either on the back of the work glove I wear on my left hand or my trousers depending.
I've been using RE-500 which really sticks to fingers (kinda like a booger) unless you lick you finger first, which is even more unappealing ;-) We found that a flat wooden stick, like a thin tongue-depressor, works well since the glue doesn't stick to it.
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392

Great info Sam, thanks. A few comments...

Sam Lightner, Jr. wrote:If you fill the hole almost to the outer edge the glue will find the spots it should be in. It will go there before it comes out.
Yes. I'm sure you've run into the void issue in Thailand, right? Sometimes I can put in a little more glue (1/4 pull) and get a nice mushroom, sometimes not and I have to drill another hole. Either way, I need to get the bolt out of the hole, and I was worried that might be a problem.

Sam Lightner, Jr. wrote:I often angle the bit up and run it for a second just after drilling to depth. I let the tip hit about 1/3 of the way into the hole. This makes a notch in the top of the shaft. It is no longer a perfect tube. Now the glue not only adheres to the wall, but is also actually wider on the inside than on the outside making it mechanical.
Wow, interesting idea, especially for soft rock.

Sam Lightner, Jr. wrote:If you carry a bag of dirt up with you, and throw that dirt at the glue after you have placed the bolt, it hides the glue very well.


I've found that RE-500, at least, loses it's color after about a year. It ages to a nice reddish-tan, which blends very well with the rock. I spoke to one of the Hilti tech guys who said that was intended: bright pink so you can see it easily when using it, then ages to a nondescript tan.
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
Morgan Patterson wrote:But as someone who has also placed glueins I'm left scratching my head about the advantage of a hammer in glue-in vs just drilling the hole an 1/8 or 1/16th bigger and just sliding it in without hammering it? I'm also thinking as your bit wears you going to have a smaller hole and more hammering and a significantly more difficult bolt to actually remove if someone smashes it or it needs to be replaced.
As you say later, the hammer-in is so it stays put in an overhanging placement. And the Wave-bolt is intended to allow people to bolt ground-up as well, although the mere thought of a zipper scares the shit outta me.

Drilling a larger hole has certainly occurred to me, but as I said, I've seen some ugly placements and was wondering why.
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
John Wilder wrote:ClimbTech makes the tool and it is specifically for the Wave bolt. It's well worth the $40.
Greg says it doesn't fit other bolts, so I probably can't use it. The Mfg of my bolts says I only need to tap in the last 1/2", so I probably don't need one,I hope!

John Wilder wrote: Terrycloth for smoothing- its super easy to do. Takes just a few seconds.
Hmmm... the glue I'm using sticks like taffy to just about everything. That's why I use a stick to do the smoothing. We also found that using a single rag, terrycloth or otherwise, gets pretty messy; eventually everything it touches gets glue on it.

We pre-cut 3" x 3" squares of old sheet (could be anything). Use one square per bolt (or so) and place the used square in a plastic bag for later disposal. Keeps everything clean, especially me!

John Wilder wrote: I like the pound in nature of the Wave- it means I dont have to mess with it, twisting, holding or duct taping it into the wall. I can let go of it as I start seating it to wipe up any glue coming out of the hole and it wont slide out of the hole- meaning I can clean up as I go...
I totally agree. I've had to deal with bolts slowly sliding out of their hole, usually after I've jugged up to the next placement :-( I'm looking forward to bolts that stay put.
Morgan Patterson · · NH · Joined Oct 2009 · Points: 8,945

Thnx guys! And I can even say I learnt something today!

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
Greg Barnes wrote:I've only placed a couple in a test rock (granite), but I had to hammer nice and hard and certainly couldn't twist it. I had to funk it to remove it (testing that one without glue of course!), not nearly as hard as funking a piton, but it did take a good amount of force. John is replacing on soft Calico Hills sandstone at Red Rocks, so the holes will be bigger and it'll be easier to move the bolts.
Hi Greg! You're the fourth person, three others off-line, who said they had to hammer hard. It seems there's variation due to rock, drill size, maybe mfg-tolerances, more?

The ugly bolts I've seen were in limestone and granite. With the input I've gotten so far, it's not clear to me what the cause is, or causes are.

One thing I discussed with my bolt mfg, is that hole-size is critical. So I had him put in some 14mm drills, which are very hard to get here in the US.
Brendan N · · Salt Lake City, Utah · Joined Oct 2006 · Points: 405

I love the Wave Bolt after installing about 100 this summer. I have heard they hold ~1000lbs. without any glue, but I have not bolted on lead because Hilti recommends against weighting the glue while it cures.

The best hammer we have found is a rubber mallet. It won't ding up the stainless steel and is easier than wrapping a wall hammer in denim.
Reaming out the hole reduces the need to wail on the bolt. While you are reaming you can also add a little counter-sink to the bottom of the surface hole for the curve of the wave bolt to sit in.

For best glue application I like to put 1/3 in the back of the hole, 1/3 in the middle and 1/3 near the edge of the hole. This makes sure that a void doesn't swallow all of the glue, as well as giving a good seal around the edge. To clean up the surface glue we use pre-cut 5"x5" scraps of fabric and toss them when they become saturated with glue. You can clean the surface glue in-between hammer blows if it is splooging.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
Brendan N. (grayhghost) wrote: For best glue application I like to put 1/3 in the back of the hole, 1/3 in the middle and 1/3 near the edge of the hole. This makes sure that a void doesn't swallow all of the glue, as well as giving a good seal around the edge. To clean up the surface glue we use pre-cut 5"x5" scraps of fabric and toss them when they become saturated with glue. You can clean the surface glue in-between hammer blows if it is splooging.
Hi Brendan,

Do you mean you put in 3 individual beads of glue in the hole? Won't this cause air-bubbles which are often hard to get out?

I think most people put all the glue in the back of the hole and let the bolt squeeze the glue along the shaft and out the top of the hole. This allows the air to escape.

You've obviously had voids. Is it limestone?

You describe the glue as sometimes "splooging", which is obviously a highly technical term I"m unfamiliar with ;-) Can you describe it? Which Hilti glue are you using?
Brendan N · · Salt Lake City, Utah · Joined Oct 2006 · Points: 405

We have used Hilti 200 and 500. It takes 3 trigger pulls with the Hilti gun so I put each trigger pull in a different location. We are working in limestone, but only get voids with 1-in-20 holes drilled. I'm not very concerned with air pockets since the glue is so overkill strong and the bolt is stainless.

Splooging is just excess glue coming out of the hole as you hammer the bolt in.

JohnWesely Wesely · · Lander · Joined Nov 2009 · Points: 585

If you are using RE 500, grocery bags are pretty much the miracle cure to mess. They do an incredible job of wiping it up.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
Brendan N. (grayhghost) wrote:We have used Hilti 200 and 500. It takes 3 trigger pulls with the Hilti gun so I put each trigger pull in a different location. We are working in limestone, but only get voids with 1-in-20 holes drilled. I'm not very concerned with air pockets since the glue is so overkill strong and the bolt is stainless. Splooging is just excess glue coming out of the hole as you hammer the bolt in.
I use 2/3's of a pull for each hole. Either my glue-gun is different or I use a lot less glue (probably the latter) for the particular bolts I've been using.

AIR BUBBLES: Without an interference fit, an air bubble in the glue will push a bolt back out of the hole. If you force it in the bubble will splatter you in the face as it bursts. Of course, this depends on the viscosity of the glue; I use a tooth-paste consistency coming out of the nozzle so it stays put in an overhanging wall.

Air bubbles bursting out of the hole as a bolt is hammered in was/is my leading theory for some of the ugly placements I've seen. It explains the gaps at the surface of the hole and the "strips" of dried glue on the bolts and rock.

The number of voids I see depends highly on the features of the wall I'm at. Walls with lots of pockets on the surface also have lots of pockets below the surface. Tapping with a hammer helps, but if you drill and strike 1 or 2 grape-sized pockets, you need to increase the amount of glue, and so, must take the bolt out.

Just so you know, in my environment stainless steel is worthless. I don't know if you're bolting in the desert or someplace wetter, but I'd recommend you try to eliminate air pockets. Not necessarily for strength, but for longevity.

Limestone is porous. Water percolates behind the surface and can collect in an air-pocket and start corroding the steel. We KNOW that limestone-runoff WILL corrode stainless, especially in a crevice-like environment.
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 392
JohnWesely wrote:If you are using RE 500, grocery bags are pretty much the miracle cure to mess. They do an incredible job of wiping it up.
Do you mean plastic grocery bags used as rags?
Guideline #1: Don't be a jerk.

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