Glue in Bolts Vs. Expansion Anchors in limestone
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I am currently developing a crag and am using expansion bolts. My question to this enlightened community is why glue-ins are seen in a more favourable light? More importantly, does this difference, which I'm assuming is its attachment to the rock around the bolt, warrant the mess of glue-ins. P.S this has to do with limestone bolting in the mountains. NO humidity, SS bolts and cool temps. |
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I would think it all boils down to the quality of limestone you are dealing with and how dimensionally correct of a hole you are able to drill within that rock. I have placed glue-ins (Chem-Stud), wedge bolts and Cobra SuperSleeves, the latter ended up being *my* preferred bolt for the limestone we were climbing. |
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I decided to start using glue in's in limestone for several reasons: 1. Lots of it is soft. Ours has about a 1" crust that's bullet hard, then a soft (in comparison), spongey core. Expansion bolts like powerbolts and wedge bolts can't grab in that spongey rock. A glue in creates an insanely strong bond with the rock, eliminating that problem. 2. Glue in's are more sustainable in the long run. We will have to replace fewer bolts in the long term as most stainless steel glue in's have estimated life spans of 50-150 years depending on who you talk to. 3. I love the idea of place it and forget it. I didn't like thinking about routes I put up developing spinners with wedges bolts and becoming unsafe. Less anxiety for me! 4. Glue in's look SEXY on the wall! They can be camo'ed up real nice and are great for multi use areas. 5. Stainless steel glue ins are actually a pretty cheap option. Most people seem to be able to get glue in's for anywhere from $5-$8 after glue is factored in! Thats cheaper than a stainless powerbolt/hanger combo. 6. They're not messy once you get good at it. After you dial in how many pumps of glue it takes for it to just squeeze out of the hole, you will cut down on the mess and save glue. |
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Jimmy Yammine wrote: Freeze/thaw is a big hassle, the German Alpine Association only reckon on 10 years for mechanical bolts in Alpine environments. The second issue, especially in limestones is that the extremely high pressure at the contact point of the expansion cone combined with water in the rock could produce rapid erosion of the rock, there are some theories about regarding this but no real decision on whether this occurs, just we know the things keep coming loose. Glue-ins are generally cheaper and certainly have a lower visual impact. And they are stronger. Edit.And of course you can rap straight off them if you need to retreat or whatever. |
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8 - The in the rock portion is incased in glue lessing the chance of corrosion 9 - Better quickdraw interface no gouging no chance of it getting snagged on a bolt stud 10 - Glue ins needs very little to no maintence never need tightening or resetting to have correct orientation |
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Glue-in fixings have numerous advantages over expansion fixings:
Perhaps stating the obvious but this type of fixing does requires additional competencies and experience to install glue-ins safely and efficiently. That said, it's like most things in life, source training from an adhesive supplier and combine that with a local area mentour so as to adapt work practices to climbing. |
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I would like to thank you all for the soberest and most to the point thread I've seen on MP. I like your reasons and will be converting to glue-ins in the future. |
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One of the downsides is the practical inability to move your bolt placement, should the clipping stance prove less than ideal. Carefully sussing out placements prior to putting the drill mitigates this, but mistakes in bolt placements are not uncommon. |
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Admins, this thread should become a sticky on the advantages of glue-ins over mechanical bolts! |
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I see “rapping directly from them by threading the rope through the eye” as a disadvantage. |
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Kristoffer wrote: Please be sure to use SS hardware. In softer stone appropriate size wedge anchors (1/2") and length (4") can be entirely adequate and are reasonable. YMMV depending on your stone (limestone is generally fine).Glue ins become more and more reasonable when many routes are going up at the same time to take advantage of glue issues. Wedge types more useful for a bolt here, a bolt there, sort of approaches (or hand drilled). Jim, you got any glue-ins that fit a 3/8" or 10mm hole? |
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Josh Janes wrote: I see “rapping directly from them by threading the rope through the eye” as a disadvantage. +1 for that. I also, in general, try to keep the glue as cool as possible by placing bolts while in the shade, at cooler times of the year and/or by keeping it in a soft-sided cooler, sometimes on route. As I'm sure you know, some glues cure faster than others. I know people who stay away from certain glues due to their respective cure times. |
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Harumpfster Boondoggle wrote: I believe Jim offers solid leg bolts that fit a 10 mm hole. Scroll down to the 8mm Rod Solid Leg Bolt. |
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Gotcha, thx Bobby. |
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Josh Janes wrote: I see “rapping directly from them by threading the rope through the eye” as a disadvantage. Why is that a disadvantage? It's one reason (amongst others) why Jim developed a round bar hanger for mechanical expansion anchors when there is a need to retreat from a high point on a route. Glue-ins do not present an issue in this regard. The alternative is manky crap left behind on a hanger when people bail e.g.manky quick links that corrode shut and require a cordless angle grinder to remove.For lower offs or abseil stations then obviously replaceable wear components should be fitted. |
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Francis Haden wrote: I think he was referring to people rapping or lowering through the eye of a glue-in normally, not as a way to bail. In Durango, we have a fair amount of glue-ins for TR anchors at one crag and they are getting worn from people rapping and lowering through them. Obviously this is not good because it is not easily replaceable. After several failed attempts, some of these anchors now have additional hardware to service the wear from descending, but several sets of hardware have been stolen off these glue-ins in the past. Also, I've used Jim's rod hangers to rap directly through the hanger and I would reccomend it unless you're bailing as it will twist your rope somewhat. If you're installing a rap station to be used for descending the route then you should add a 2 quicklinks or a quicklink and a rap ring. |
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It stinks when people decide that they can steal hardware and mess it up for the rest of us. I have not done this myself, but could stainless quicklinks be added to the TR bolts and then glue the quicklinks shut with weldbond or something to stop people from stealing them? Clearly it would make replacing more annoying because they would likely need to be cut with an angle grinder or something but seems like it might be a good idea. |
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Red loctite. Or get the Fixe glue-ins with rings built in |
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Honest question what if you are bolting ground up? |
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@Benjamin, use removable bolts like the fixe triplex and then replace them afterwards :) |