Labeling Bolts

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Labeling Bolts

Postby driggs » Aug 18, 2010 10:12 am

We've been planning several re-bolting projects for some caves with sketchy bolts of unknown vintage in the hopes of making it the "final" holes drilled in the cave. I like the idea of labeling bolts to show the date/year that they were placed and possibly who placed them, in the hopes that this lets people put more trust in the anchor (or, if I placed it, less trust in the anchor!).

Here's a photo of a bolt in a Washington cave (photo by Lane Holdcroft):

Image

This looks like PVC labeled with a Sharpie marker; I've also seen people try to engrave dates directly onto hangers with shoddy results. Does anyone have other suggestions for good ways to label bolts with this sort of information, preferably ways that would last for decades?
Last edited by driggs on Aug 19, 2010 10:37 am, edited 2 times in total.
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Re: Labeling Bolts

Postby BrianC » Aug 18, 2010 10:18 am

Thin stainless with punch for dates and installer?
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Re: Labeling Bolts

Postby NZcaver » Aug 18, 2010 10:24 am

BrianC wrote:Thin stainless with punch for dates and installer?

I've seen the same thing with punched aluminum tags, also installed behind the bolt itself. Those PVC tags up on the ridge look pretty good after almost 20 years.
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Re: Labeling Bolts

Postby BrianC » Aug 18, 2010 10:26 am

NZcaver wrote:
BrianC wrote:Thin stainless with punch for dates and installer?

I've seen the same thing with punched aluminum tags, also installed behind the bolt itself. Those PVC tags up on the ridge look pretty good after almost 20 years.

They do look very well preserved.
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Re: Labeling Bolts

Postby Scott McCrea » Aug 18, 2010 10:33 am

We have used pieces of plastic (like milk carton or 1 gal OJ jug, etc) and a Sharpie. I like the PVC, tho.

Anyone have a problem with it between the rock and hanger? My theory is that the material would spread out the force applied to the rock by the hanger a bit more possibly making it stronger.
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Re: Labeling Bolts

Postby driggs » Aug 18, 2010 10:35 am

NZcaver wrote:I've seen the same thing with punched aluminum tags, also installed behind the bolt itself.


I had considered arborists' aluminum tags, which can easily be "etched" with a punch. Do they not develop nasty galvanic corrosion if installed underneath stainless steel bolts and hangers?
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Re: Labeling Bolts

Postby NZcaver » Aug 18, 2010 10:40 am

driggs wrote:I had considered arborists' aluminum tags, which can easily be "etched" with a punch. Do they not develop nasty galvanic corrosion if installed underneath stainless steel bolts and hangers?

Ah, good point. Perhaps there was some kind of spacer (like electrical tape) installed between the two metals? I tried to find photos of what I described, but no luck. Maybe I was mistaken. I think the PVC is a nicer option.

Scott McCrea wrote:Anyone have a problem with it between the rock and hanger? My theory is that the material would spread out the force applied to the rock by the hanger a bit more possibly making it stronger.

I highly doubt a strip of PVC makes any appreciable difference to the force applied to the rock or to the security of the bolt.
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Re: Labeling Bolts

Postby jharman2 » Aug 18, 2010 11:54 am

This is a very interesting topic and certainly something I never thought of. I do have to wonder why this would be necessary if all stainless hardware is used? What kind of confidence is the date trying to instill? Some people may see the date (8/92 in the example) and think "Holy cow that bolt is old wonder if I should use it?" while other people may see the date and think "Holy cow that bolt is old, must be a bomber placement I'll put my @$$ on it!".

Bolt users should be educated to identify bolts and hangers made from quality materials and torqued properly in sold rock; not just rely on a date written on a piece of PVC.
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Re: Labeling Bolts

Postby BrianC » Aug 18, 2010 12:16 pm

jharman2 wrote:This is a very interesting topic and certainly something I never thought of. I do have to wonder why this would be necessary if all stainless hardware is used? What kind of confidence is the date trying to instill? Some people may see the date (8/92 in the example) and think "Holy cow that bolt is old wonder if I should use it?" while other people may see the date and think "Holy cow that bolt is old, must be a bomber placement I'll put my @$$ on it!".

Bolt users should be educated to identify bolts and hangers made from quality materials and torqued properly in sold rock; not just rely on a date written on a piece of PVC.

so a coat hanger with the date might just be for a coat.
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Re: Labeling Bolts

Postby paul » Aug 18, 2010 12:19 pm

Locally (Peak Distict, UK) we rely on numbering in a spreadsheet based on cave, pitch and location on pitch (maybe by reference to a topo diagram) where the bolts have been placed by the Regional Caving Organisation (these are resined-in bolts). There are 350+ of these and records are kept of location, date installed, date last inspected, etc. for each individual bolt.
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Re: Labeling Bolts

Postby driggs » Aug 18, 2010 12:34 pm

jharman2 wrote:I do have to wonder why this would be necessary if all stainless hardware is used? What kind of confidence is the date trying to instill?

Bolt users should be educated to identify bolts and hangers made from quality materials and torqued properly in sold rock; not just rely on a date written on a piece of PVC.


Ah, but all stainless hardware is exactly the problem! There is no way to identify the age of a stainless anchor if it looks exactly the same three decades after being placed. Does its age matter? Maybe. I'm certainly going to give it a more thorough check, perhaps even attempt to tighten the nut with a wrench, if it is older than I am.

How exactly does one identify that a bolt is "torqued properly" or that it is made of "quality materials"? I don't cave with a torque wrench, and whether it is a good idea or not, I don't tighten nuts down unless I see a spinning hanger or wobbly bolt. Is the fact that a bolt appears to be made of stainless steel enough of an indicator that it is "quality", or that it was set with a hammer drill rather than someone banging on a bit with a sledgehammer?

`SS 3.5" RIGGS 2009` sure tells me more than "that looks solid."

I agree with you 100% that it is up to the person whose butt is on the line to evaluate every single anchor, regardless of how it looks or what a tag says on it. The point of a label isn't so the user becomes complacent, it's to provide more information for that evaluation. At least if I know that the bolt was placed in the "modern age" and/or by someone competent - or at least confidant enough to sign their name to it - I can assume some level of quality.
Last edited by driggs on Aug 18, 2010 1:36 pm, edited 1 time in total.
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Re: Labeling Bolts

Postby Jeff Bartlett » Aug 18, 2010 1:28 pm

Specifying the depth of the bolt also allows the bolt user to determine whether the bolts have been properly spaced in the rock, although it's kind of a moot point ten years later. I've definitely seen bolts placed very close together and wondered "are these 2.5-inch anchors or 4-inch anchors?"

Also, just because the hanger is indentifiable as stainless doesn't mean the anchor is. In most placements there isn't much of the threaded anchor itself visible beyond the nut, and I'll openly admit that, in the absence of obvious and/or heinous corrosion, I can't definitively say that the anchor is. Of course, in the absence of obvious and/or heinous corrosion, it's not a problem yet and therefore kinda doesn't matter.

My goodness, I'm rambling here.
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Re: Labeling Bolts

Postby jharman2 » Aug 18, 2010 3:13 pm

driggs wrote:Ah, but all stainless hardware is exactly the problem! There is no way to identify the age of a stainless anchor if it looks exactly the same three decades after being placed. Does its age matter? Maybe. I'm certainly going to give it a more thorough check, perhaps even attempt to tighten the nut with a wrench, if it is older than I am.


I don't know how or if a SS anchors age factors into its integrity. I guess this is a question for a material scientist.

driggs wrote:How exactly does one identify that a bolt is "torqued properly" or that it is made of "quality materials"? I don't cave with a torque wrench, and whether it is a good idea or not, I don't tighten nuts down unless I see a spinning hanger or wobbly bolt. Is the fact that a bolt appears to be made of stainless steel enough of an indicator that it is "quality", or that it was set with a hammer drill rather than someone banging on a bit with a sledgehammer?


It is actually quite simple to determine if a bolt is torqued properly. The Confast website [1] indicates that a 3/8" wedge anchor should be torqued to 25-30 ft-lbs. Assuming you carry a 6" wrench this means that you need to apply 50-60 lbs of force to the end of the wrench to achieve the proper torque. I prefer a 9" offset box end wrench. With 9" you can use 3" for grip meaning that you are actually using a 6" torque arm. 50-60 lbs is a pretty wide range and is at the top end of what most folks are capable of generating without straining.

As for quality materials, you should be able to closely inspect the bolt and hanger and easily determine if they are galvanized or stainless. A quality material will be shiny and show no signs of rust. Your picture at the beginning of this thread is a great example of a good SS rig!

Does the method of drilling really matter if the placement is solid and the bolt is torqued down?

driggs wrote:`SS 3.5" RIGGS 2009` sure tells me more than "that looks solid."


You have misrepresented what I am trying to convey. Inspection involves much more than standing at a distance and saying "that looks solid". During inspection you are looking for several key aspects of the anchor which I believe I have touched upon. I could go much deeper but I feel it is moving off topic. Telling me the name of the rigger might be helpful and it might not. It does say you are confident enough to put your name on your work, but we can find all manner of bad engineering that has been signed off.

I do agree that knowing the length of the bolt does instill some confidence. I don't think that labeling bolts it is a bad practice but I certainly caution against trusting an anchor just because it has a label. Inspection of the anchor is the only way to definitively determine if it is safe to use.

As an aside, I believe that permanent rigging in heavily visited tourist caves (like you are talking about) should involve a very significant level of redundancy. If I come across a 30 year old rig that is redundant and clean, I will happily use it.

[1] http://www.confast.com/products/technic ... nchor.aspx
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Re: Labeling Bolts

Postby driggs » Aug 18, 2010 3:46 pm

jharman2 wrote:I don't know how or if a SS anchors age factors into its integrity. I guess this is a question for a material scientist.


I don't think this is a question for a material scientist; it is common sense that the older an anchor is, then the more general use, wear-and-tear, intrusion of the rock-bolt interface by humidity/water, potential shock-loading, subsequent fracturing of rock along an artificially-weakened hole, etc. that the anchor system may have seen. Replace "anchor" with "car", "ox", or "knee joint" and the answer is exactly the same. More age equals more use equals more potential for wear of the system, regardless of whether the stainless steel bolt itself ever corrodes or weakens.


jharman2 wrote:Does the method of drilling really matter if the placement is solid and the bolt is torqued down?


This is a question I'd love to have answered with hard data; my suspicion (fear?) is that, yes, a hand-drilled hole may have a lower pull-out strength than a hole drilled with a rotary hammer drill (or, saying it another way, a hand-drilled hole is easier to screw up). If I know that a bolt was placed this decade rather than in the 1980's, I'm more likely to assume it was placed with a hammer drill, and not have that doubt in the back of my mind, encouraging me to place a new bolt that I know is drilled with one. [If someone wishes to comment further on this topic, please start a new thread.]


jharman2 wrote:I don't think that labeling bolts it is a bad practice but I certainly caution against trusting an anchor just because it has a label. Inspection of the anchor is the only way to definitively determine if it is safe to use.


Excellent, then we are in agreement. I felt it unnecessary to even put the disclaimer on my original question that one still need inspect a bolt that your life depends on, despite it having a warm fuzzy "born on date" attached.

My question for you, then, is if you believe that placing a label like in the above example is a good practice, and if not, why?


jharman2 wrote:If I come across a 30 year old rig that is redundant and clean, I will happily use it.


And this is exactly my goal! To prevent the bolt garden in Carpenter-Swago from turning into the bolt farm in Cass Cave. I personally feel that in caves like this, adding a label to a bolt may help the user evaluate that rig.

Edit for clarification: So it doesn't sound like I'm contradicting myself by saying at the same time both "older bolts may be more suspect" and "making a bolt's age known prevents over-bolting"... The example cave, Cass, has been explored heavily since the mid-1940's has no fewer than 17 bolts placed at the Belay Loft, including two brand new(???) stainless 3/8" diameter, unknown length bolts inexplicably-placed next to a one-ton natural tie-off boulder, rather than out over the drop. I believe that at least two of the four large, rusted, steel anchors over the big drop were placed in the 90's based on oral tradition, but I sure have no way of being certain of that; and despite the fact that I can yank on them or crank on them, I can only guess as to whether they are suitable for a rescue load. If a tag told me they were 6" deep and placed in 1995, I'd let you haul me up on them without protest; probably even if it said 6" deep and 1975.

Perhaps I'm totally wrong and modern-looking manufactured stainless hangers on "solid enough" bolts are good enough for everyone to trust 10 years from now? 20 years from now?
Last edited by driggs on Aug 18, 2010 4:20 pm, edited 2 times in total.
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Re: Labeling Bolts

Postby Jeff Bartlett » Aug 18, 2010 3:57 pm

driggs wrote:I personally feel that in caves like this, adding a label to a bolt helps the user evaluate that rig.

'specially if you write "THIS BOLT IS TOTALLY TEH AWESOME" and sign it with Bill Cuddington's NSS number.
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