Loose Bolts

[EWolfe]

OK, I will concede that the only acceptable usage of wedgebolts is in an emergency bolt kit.

 

My Bad

[ZONK]

will have to stop there and scope on it tomorrow. is this the route the fixed line was hanging on for about a week or so not long ago ?

[sobo]

Thanks, Sobo. Those Petzl long life bolts are pretty spendy, no? Have you ever seen them used?

 

I've seen those "self driling" bolts at PMS or some other local shop in years past, but never tried 'em. If you were just carrying a couple of them for a possible bail out option, I can see the utility in not carrying the drill. What is your opinion of them?

They're going for about 6 GBP right now, which converts to about $12 each, so yes, pretty spendy indeed. I've never used them/seen one used.

 

RE the self-drilling ones, I like my kit just fine. It's pretty compact; fits in a small stuff sack (except for the hammer). Sometimes it's difficult to extract the "snap-off" portion of the bolt head out of the holder. It comes with a tapered drift pin to assist in that effort, but sometimes it can be a real bugger to get the spent head out. Good thing is, if you're only placing one bolt (like to bail from, or because you only need one bolt), you can complete the entire installation without removing the spent head from the holder. But as you have probably surmised by now, the down side is that you need more than just a hammer to place them. You also need the holder. It holds the bolt with one side, and the other side is the strike plate for your hammer. Then you need the drift pin to extract the spent head out of the holder. And you need the Allen wrench to tighten the stud that holds the hanger, but that's machined into the other end of the holder, so no BFD there.

 

I should take a pic of the kit for you and PM it to you, since I can't find one online.

[sexual_chocolate]

 

anyway, because of the rock issues at this crag, a one piece wedge bolt seems to be an unsafe approach.

 

Is this because of the rock issues, or because the bolt was placed incorrectly?

 

my thought is that any purely mechanical bolt will slowly loosen because of the decomposing and granular nature of this particular crag.

on shitty concrete, we have significantly OVERDRILLED the hole and used an epoxy bolt to keep the bond stresses between the wall holes and the epoxy plug as minimal as possible...you basically are "rebuilding" the local area with an epoxy grout....

 

freeze thaw will fuck you though...the advantage of a slip cone for mechanical bond is that its "adjustable" in the sense that the bolt can be retightened to account for slop in the system...one way to hedge this is to increase the length of embedment for either system...

 

good points. i imagine then that a 4" minimum 3 or 5 piece 3/8th's would be a good starting point when the rock's like this stuff....

 

 

yeah it was kinda strange to see a bolt and hanger come flying out of the rock on tr! the first thought through my head was "what about the anchors?" (which really shouldn't even be over the lip where they are, since the last moves are no gimme, and there are decent cold shuts up higher).

 

[sexual_chocolate]

will have to stop there and scope on it tomorrow. is this the route the fixed line was hanging on for about a week or so not long ago ?

 

it's the bolted line 30' left of spaghetti sauce, through blocky face climbing and progressively steeper to a seam with flaring pods up near the top. maybe 20 degrees overhanging near the top.

 

pull the loose anchor bolt and leave the other one (a good place for a last bolt), and add two down lower!

[RuMR]

Matt, if you drill an 8 inch deep hole and put a 2 inch long bolt in it, do you think the extra 6 inches of dead air space reduces or increases stability vs. a hole with no airspace?

has no effect if its a 5 piece expansion bolt...

[RuMR]

When you place an expansion bolt, the wedge/cone is forced into the bolt somewhat by the sides of the hole, but the back of the hole also has an effect. A bolt that has dead space behind doesn't have the wedge forced as tightly into the sleeve and hence is weaker.

 

Put another way - if the bolt, like matt suggests, can be tapped deeper into the hole by hammer blows - it can also be pulled OUT by the same forces. If the bolt is snug against the back wall of the ole and can't be tapped further in, it also has the wedge deeper into the sleeve and is more solid as a result.

you are absolutely smokin' crack...you must be hangin with that kevretard kid too much...

[summerprophet]

Here is my .02.

 

I have placed over 30 bolts. Both by hand and with a power drill. Here is my take on answering a few of the misconceptions floating around here.

 

Hole depth:

In some cases hole depth is pertinant to the integrity of the hole. HOWEVER.... modern bolts like this are less common (and far more expensive) than the equivalent to the typical epoxy or expansion wedges. Old stardrive, ,and mashhead bolts required a specific depth to be set properly.

 

Modern expansion wedge bolts do NOT require a specific depth, and as a matter of fact, if you have a power drill at hand, you should actually drill the same depth as the length of the bolt, so if the bolt is bad (bends or hits a soft spot) you can bury the bolt, and hide the hole.

Obviously hand drilling you stop drilling as soon as possible.

 

If it was indeed an sleeve wedge style expansion bolt (a la fixe or redhead) I would suspect the wrong size bit was being used. a 10mm bit is close enough to look correct, and will sometimes even hold the bolt enough to appear good. The bolt can blow around 5 to 30 lbs force, less if it was hand drilled. (Hand drilling makes a slightly larger, and less circular hole)

 

While epoxying wedge bolts might work, I would not recommend it.

Firstly, you are tossing dollars away, secondly, the sleeve would create an air pocket in the epoxy, weakening the placement, and lastly, those in the know, can actually tell what style of bolt it is by the external appearance. If I see a sleeve wedge hanging out of sandstone I am going to assume that whoever placed it had no idea what they are doing and may waste my time and money ripping and replacing the bolts with glue ins.

 

If this is actually a new project, I would say we have to determine who is putting in these bolts, and put him on the right track. And determine and replace all the other deathtraps he may have set up for the rest of us.

 

 

 

Edited May 14, 2008 by summerprophet

[RuMR]

over 30 bolts does not an expert make...

 

sorry bud, hardly an expert...i have a hard time seeing a bolt made of shitty steel bending from the driving...not gonna happen unless the hole is seriously undersized...then you have a bigger deal to worry about...

 

I can just give you the engineering side of bolts buried in concrete...rock is too fickle...hell those bolts could've have been fine but there could've been gas pockets in the vicinity of the holes...

 

the best deal is to use a properly placed epoxied bolt, period....FWIW, WSDOT and IBC do not even allow mechanical bolts for shock loading...go figure...

 

 

[summerprophet]

Concrete and Real rock are not the same thing my friend.

 

Expansion bolts and epoxy bolts both have their place. Epoxy bolts are not the end all solution to bolt placement. In hard rock the drill hole will be very smooth sided, and the epoxy will not penetrate the rock, creating a cylendar of glue with minimal adherance. The benefit of epoxy is it penetrates into the pores of the softer rock (and concrete) creating a placement structure far greater than the size of the meager hole.

 

And I never claimed to be an expert, just have knowledge willing to share, and experience in these matters.

 

And as far as bending, the "shitty steel" (actually some of the best steel available) can bend when the bolt binds in the hole.

 

And if your gas pocket theory is true, the bolt would fracture out the rock once you tightened the bolt down, causing it to spin in the hole....... see my statement about drilling extra deep.

Edited May 14, 2008 by summerprophet

[Peter_Puget]

There are bolts that require one to drive it with a hammer into the bottom of the hole for the shaft to expand. Some manufacturers of these expansion-style bolts are Hilti, Mammut, and Petzl.

 

The Longlife does most certainly not require one to drive it into the bottom of the hole to work. You can place a longlife into a hole a mile deep and it will work.

 

In hard rock the drill hole will be very smooth sided, and the epoxy will not penetrate the rock, creating a cylendar of glue with minimal adherance.

 

I think that you maybe wrong here.....

 

 

 

Edited May 14, 2008 by Peter_Puget

[RuMR]

Concrete and Real rock are not the same thing my friend.

 

Expansion bolts and epoxy bolts both have their place. Epoxy bolts are not the end all solution to bolt placement. In hard rock the drill hole will be very smooth sided, and the epoxy will not penetrate the rock, creating a cylendar of glue with minimal adherance. The benefit of epoxy is it penetrates into the pores of the softer rock (and concrete) creating a placement structure far greater than the size of the meager hole.

 

And I never claimed to be an expert, just have knowledge willing to share, and experience in these matters.

 

And as far as bending, the "shitty steel" (actually some of the best steel available) can bend when the bolt binds in the hole.

 

And if your gas pocket theory is true, the bolt would fracture out the rock once you tightened the bolt down, causing it to spin in the hole....... see my statement about drilling extra deep.

as far as "shitty steel", i was referencing your comment about "bad bolts"...but maybe I should've said "shitty placement"? bolt binding in the hole is an indicator that your bit is worn and you've consequently drilled the hole too small...

 

FWIW there was a rash of bad steel rawl bolts out there in the 90's...knockoffs that carried the rawl markings..

 

I can guarantee you that a properly installed epoxy bolt will fail the steel before you fail the bond even in hard rock...are you trying to really tell me that the rock won't bond while the steel (pretty slick and hard, wouldn't you say?) will???

 

5 piece bolts do have their place...

Edited May 14, 2008 by RuMR

[bwrts]

...hell those bolts could've have been fine but there could've been gas pockets in the vicinity of the holes...

 

the best deal is to use a properly placed epoxied bolt, period....

okay rudy, gas pockets in granodiorite? my god!

likely the bolt was drilled into an inclusion of country rock (not granodiorite, specifically the original rock in the area which the magma intruded), which was obviously weaker. I have not personally examined this section of the cliff but I know the general area is ripe with such features. Also, you don't get gas pockets in granitic-type rocks. This is because of the generalized cooling time... the magma cools very slowly due to the heat and where its located beneath the surface the earth. Volcanic rocks that have gas bubbles (like basalt) is due to the rapid cooling process atop the land surface.

 

the rock is somewhat decomposing and granular, so any bolt placed there should be epoxy-reinforced.

 

it does bring into question the integrity of hardware, all of which should be checked occasionally and any deficiencies pointed out in forums such as this.

 

there is at least one other bolt on the route besides the anchor bolt that also moves.

 

More probable than not, the bolt pulled because the rock quality in the section of the cliff is poor and with the outward thrust of quickdraw/rope it was yanked free.

 

As for the integrety of the bolts question: really one should ask is why was this crap bolted in first place. I mean seriously, the bolter totally overlooked resurrecting perfectly good cracks to the right (inbetween spaghetti sauce and "beast") which were full of dirt and forgotten-- now cleaned up a bit with a few more ascents. one is 11- and one is 10-.

 

-Yeah the "beast" is cool looking and yep, its steep, powerful and hard climbing but honestly do you think all sections of cliff should be climbed?

 

Anyrate, I imagine any bolt there will eventually work loose and fallout due to the grainy nature of the rock. Differential Erosion at work again.

 

[RuMR]

...hell those bolts could've have been fine but there could've been gas pockets in the vicinity of the holes...

 

the best deal is to use a properly placed epoxied bolt, period....

okay rudy, gas pockets in granodiorite? my god!

likely the bolt was drilled into an inclusion of country rock (not granodiorite, specifically the original rock in the area which the magma intruded), which was obviously weaker. I have not personally examined this section of the cliff but I know the general area is ripe with such features. Also, you don't get gas pockets in granitic-type rocks. This is because of the generalized cooling time... the magma cools very slowly due to the heat and where its located beneath the surface the earth. Volcanic rocks that have gas bubbles (like basalt) is due to the rapid cooling process atop the land surface.

 

the rock is somewhat decomposing and granular, so any bolt placed there should be epoxy-reinforced.

 

it does bring into question the integrity of hardware, all of which should be checked occasionally and any deficiencies pointed out in forums such as this.

 

there is at least one other bolt on the route besides the anchor bolt that also moves.

 

More probable than not, the bolt pulled because the rock quality in the section of the cliff is poor and with the outward thrust of quickdraw/rope it was yanked free.

 

As for the integrety of the bolts question: really one should ask is why was this crap bolted in first place. I mean seriously, the bolter totally overlooked resurrecting perfectly good cracks to the right (inbetween spaghetti sauce and "beast") which were full of dirt and forgotten-- now cleaned up a bit with a few more ascents. one is 11- and one is 10-.

 

-Yeah the "beast" is cool looking and yep, its steep, powerful and hard climbing but honestly do you think all sections of cliff should be climbed?

 

Anyrate, I imagine any bolt there will eventually work loose and fallout due to the grainy nature of the rock. Differential Erosion at work again.

I will grant that bovinewarts knows his rock...

[JosephH]

Epoxying expansion bolts is just a bad idea. Pretty much what glue-ins are made for if you are intent on bolting it.

[builder206]

Some of you take highly-engineered industrial products and, like monkeys, turn them over in your hands and fabricate your own personal theories about how to use it. Why don't you log onto the websites of the manufacturers and actually read the instructions? The technical data for all this stuff (and data about what *not* to do) is extensive.

 

When epoxying bolts into concrete, not only do you want the hole smooth-sided, you want it as smooth as you can get it, and then you clean it out with flowing water and dry it with compressed air. There are no "pores" in concrete and most assuredly no epoxy molecule is anywhere near small enough to "seep" into any space around either rock or cement crystals in a way that is mechanically meaningful. On the contrary, you want the hole sides to be as smooth as possible to maximize continuous contact area for the epoxy mass. A rough hole, or a hole that hits spaces in rock or concrete, is subpar because the epoxy is so thick it will just cover over the void, creating a bond-breaker.

 

Expansion bolts work by the expansion mechanism. Epoxy bolts use epoxy. They are different tools for different uses and materials. They shouldn't be mixed HOWEVER you can glop epoxy over the nut to assure it will stay fixed. You can also use paint; the purpose is to keep air and water from seeping down into the treads. Think Loctite.

 

There are materials specific for every application. The key is to use the right tool, rather than arguing over what must always or never be done with a narrow, limited tool kit.

[RuMR]

Epoxying expansion bolts is just a bad idea. Pretty much what glue-ins are made for if you are intent on bolting it.

i'm not suggesting epoxying expansion bolts...duh...

[RuMR]

Some of you take highly-engineered industrial products and, like monkeys, turn them over in your hands and fabricate your own personal theories about how to use it. Why don't you log onto the websites of the manufacturers and actually read the instructions? The technical data for all this stuff (and data about what *not* to do) is extensive.

 

When epoxying bolts into concrete, not only do you want the hole smooth-sided, you want it as smooth as you can get it, and then you clean it out with flowing water and dry it with compressed air. There are no "pores" in concrete and most assuredly no epoxy molecule is anywhere near small enough to "seep" into any space around either rock or cement crystals in a way that is mechanically meaningful. On the contrary, you want the hole sides to be as smooth as possible to maximize continuous contact area for the epoxy mass. A rough hole, or a hole that hits spaces in rock or concrete, is subpar because the epoxy is so thick it will just cover over the void, creating a bond-breaker.

 

Expansion bolts work by the expansion mechanism. Epoxy bolts use epoxy. They are different tools for different uses and materials. They shouldn't be mixed HOWEVER you can glop epoxy over the nut to assure it will stay fixed. You can also use paint; the purpose is to keep air and water from seeping down into the treads. Think Loctite.

 

There are materials specific for every application. The key is to use the right tool, rather than arguing over what must always or never be done with a narrow, limited tool kit.

[G-spotter]

Thanks, Sobo. Those Petzl long life bolts are pretty spendy, no? Have you ever seen them used?

 

I've seen those "self driling" bolts at PMS or some other local shop in years past, but never tried 'em. If you were just carrying a couple of them for a possible bail out option, I can see the utility in not carrying the drill. What is your opinion of them?

They're going for about 6 GBP right now, which converts to about $12 each, so yes, pretty spendy indeed. I've never used them/seen one used.

 

$9.75 CDN at MEC

petzl longlife

[sobo]

...There are no "pores" in concrete...

WTF? So all that money that I have clients spend on MasterBuilders AE-90 is just going to waste? Shit, I'll never spec air-entrained concrete again. Ever!

 

There are materials specific for every application. The key is to use the right tool, rather than arguing over what must always or never be done with a narrow, limited tool kit.

This does get my :tup:

[RuMR]

i love it when non engineeers talk to enginerds... :-)

[builder206]

...There are no "pores" in concrete...

WTF? So all that money that I have clients spend on MasterBuilders AE-90 is just going to waste? Shit, I'll never spec air-entrained concrete again. Ever!

 

You know, I wrote that then thought, "except for...naw, no one will bring up air entrainment." But still, the "pores" are too small for epoxy to enter.

 

Spec Sika. Their schwag is cooler than MB's.

[RuMR]

builder206, what do you do for a living??

[builder206]

As little as possible.

[rob]

As little as possible.

 

Reminds me of a funny joke:

 

"How many people work in your office?"

 

"Oh, about 50%"