|
Ope
Mar 31, 2012, 5:18 AM
Post #1 of 16
(10369 views)
Shortcut
Registered: Mar 31, 2012
Posts: 6
|
Any advice on what to do when bolting in limestone and you can only drill tru about 2"of solid rock before hitting a void to where a 3" expansion bolt will no longer work. Would glue-ins be better?
Thanks,
|
|
|
|
|
USnavy
Mar 31, 2012, 9:10 AM
Post #2 of 16
(10336 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
Ope wrote: Any advice on what to do when bolting in limestone and you can only drill tru about 2"of solid rock before hitting a void to where a 3" expansion bolt will no longer work. Would glue-ins be better? Thanks,
But to answer your question, a glue in would be the only option, you absolutely must not use a expansion bolt in that type of placement! If you ever hit a pocket or void, you must drill a new hole or use a glue in, never place an expansion bolt in a void! The only exception is if you are using some crazy long bolt (such as, to bolt a flake on) and you hit a small pocket but then continue drilling into solid rock. The idea is that the expansion clip/cone must be in deep and solid rock, or else the bolt could rip with very little force.
However, if you did use a glue in bolt, you cannot simply just squirt some epoxy in the drilled hole and call it a day. If you just fill the drilled hole with epoxy, the bolt is just going to push the epoxy into the void as you insert it, leaving you with a compromised bolt. So the alternative is to fill the entire void with epoxy or use a screen such one of these: http://www.us.hilti.com/...on.jsf?nodeId=-60845 However, even with a screen you are going to have problems.
So in summary, the best (and only) option is to choose a different placement. Place the bolt higher up and hang a long draw. Place the bolt before the tufa or after it. Make the route go somewhere else. There are many options, but a compromised bolt placement should never be one of them. Always take the time to place bolts in solid, contiguous rock.
btw, what type of bolts are you using?
(This post was edited by USnavy on Mar 31, 2012, 9:13 AM)
|
|
|
|
|
Ope
Mar 31, 2012, 2:08 PM
Post #3 of 16
(10310 views)
Shortcut
Registered: Mar 31, 2012
Posts: 6
|
Hilti KB3 Bolt 3/8" x 3"
Thanks for the advice.
|
|
|
|
|
guangzhou
Apr 1, 2012, 2:30 AM
Post #4 of 16
(10252 views)
Shortcut
Registered: Sep 27, 2004
Posts: 3389
|
Ope wrote: Any advice on what to do when bolting in limestone and you can only drill tru about 2"of solid rock before hitting a void to where a 3" expansion bolt will no longer work. Would glue-ins be better? Thanks,
Are you drilling in a Tufa or the face holding a tufa.
Tufa's vary tremendously, got any photos? Personally, I do my best to avoid having the bolt in the ctual tufa when ever I can.
Where is this. Sometime, the best option is to drill a hole right through the tufa itself and use a sling instead of a bolt. Sometime a permanent sling tied off works well.
|
|
|
|
|
USnavy
Apr 1, 2012, 6:37 AM
Post #5 of 16
(10229 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
Ope wrote: Hilti KB3 Bolt 3/8" x 3" Thanks for the advice.
|
|
|
|
|
Ope
Apr 1, 2012, 2:57 PM
Post #6 of 16
(10196 views)
Shortcut
Registered: Mar 31, 2012
Posts: 6
|
I would post a photo just not sure on how to do it yet. I have tried beside the tufa and in the tufa. I used my hammer to sound the rock and drilled where it sounded most solid. As you drill through the first few inches it's all good then the last half or quater there is a void. Not all the rock is this way. I'm going to switch to glue-ins. Has anyone used PL 9000 as a glue for glue-in bolts.
I think that drilling thru the tufa and threading is a last resort for this wall but none the less still an option.
Oh and the area is under wraps, top secret, but will tell you this, it's fricken the kewlest tufa climbing.
I'll post a photo when I figure out how!
Thanks,
Ope.
|
|
|
|
|
Ope
Apr 1, 2012, 3:05 PM
Post #7 of 16
(10191 views)
Shortcut
Registered: Mar 31, 2012
Posts: 6
|
Kewl US Navy ya Im going to use glue-ins, as the research online seems to show this is the way. What do you think of PL 9000 for the glue?
Thanks,
Ope
|
|
|
|
|
guangzhou
Apr 2, 2012, 2:07 AM
Post #8 of 16
(10127 views)
Shortcut
Registered: Sep 27, 2004
Posts: 3389
|
Glu-in is nice, but really dependends on how big the pocket you're drilling into is.
In one limestone wall I was bolting, I had a similar issues, the solution for me on that wall was three bolts that were 11 inches long. That put me through the pocket in back in solid rock for a while.
Instead og wedge bolts, if the pocket is narrow and solid rock is found behnd it, you can also use a sleeve anchor instead.
|
|
|
|
|
USnavy
Apr 2, 2012, 6:21 AM
Post #9 of 16
(10091 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
Ope wrote: Kewl US Navy ya Im going to use glue-ins, as the research online seems to show this is the way. What do you think of PL 9000 for the glue? Thanks, Ope
However the fact that you are asking this question tells me you need to get some additional shadow time from someone familiar with using glue in bolts. Placing glue-in bolts is an advanced task which demands knowledge in the field, using the wrong adhesive or poorly preparing the hole (by failing to properly clean, brush, or blow the hole) can lead to a critically weakened bolt placement. Also, failing to use a bolt that is adequately threaded or has adequate mechanical keying in it can lead to the bolt ripping from the epoxy (bond failure). So you have to use the right epoxy, the right type of bolt, and you have to prepare the hole correctly. Placing glue-in bolts also presents the bolter with air pocket related issues. There is technique with placing glue-in bolts in an epoxy filled hole. Simply slamming the bolt into an epoxy filled hole can easily create an air pocket. An big air pocket in the epoxy can greatly reduce the pull out strength of the bolt.
Here is an article to get you started: http://climbargolis.com/Glue-inBoltDesign.htm
As far as posting pictures goes, just host the picture on Image Shack and copy and paste the link, thats all we need.
(This post was edited by USnavy on Apr 2, 2012, 6:35 AM)
|
|
|
|
|
mojomonkey
Apr 2, 2012, 12:11 PM
Post #10 of 16
(10055 views)
Shortcut
Registered: Aug 13, 2006
Posts: 869
|
Ope wrote: Kewl US Navy ya Im going to use glue-ins, as the research online seems to show this is the way. What do you think of PL 9000 for the glue? Thanks, Ope
This thread, combined with its mountain project partner are either mildly amusing, or sad. You gloss right over "research" that doesn't result in the end you desire. Hope you don't bring a tufa with you if you whip on one of your bolts, and that your area stays secret enough that nobody else is tempted to climb on your handiwork.
|
|
|
|
|
Ope
Apr 2, 2012, 5:42 PM
Post #11 of 16
(9987 views)
Shortcut
Registered: Mar 31, 2012
Posts: 6
|
Thanks US Navy! mojomonkey I'm sorry you feel this way.
Ope.
|
|
|
|
|
Ope
Apr 2, 2012, 6:26 PM
Post #12 of 16
(9966 views)
Shortcut
Registered: Mar 31, 2012
Posts: 6
|
What's your view of the Fixe Glue In Bolt For 12mm Hole? What bolts do you use?
Thanks,
Ope.
|
|
|
|
|
shotwell
Apr 2, 2012, 7:51 PM
Post #13 of 16
(9930 views)
Shortcut
Registered: Jan 6, 2009
Posts: 366
|
Ope wrote: What's your view of the Fixe Glue In Bolt For 12mm Hole? What bolts do you use? Thanks, Ope.
Ope, I'll try with you as you seem to be missing everyone else's point.
You're going to rip the placement in this tufa if you use a standard length bolt, even a glue in.
You need to use something that is long enough to reach to your normal depth of embedding in the solid stone behind the 'void.' You also need to find a way to reduce the leverage on the part of the bolt that won't be in this solid stone.
If there isn't solid stone behind the 'void,' you're going to have a pretty damn high likelihood of ripping the bolt. If you improperly install this bolt (which is going to be pretty damn easy to do) you're going to have a pretty damn high likelihood of ripping the bolt.
If you're serious about this project try to get in touch with Jim Titt of Bolt Products. If anyone can help you find a reasonable solution, it is likely to be him. If he tells you not to move forward with this, consider it the voice of experience warning you.
http://climbargolis.com/AboutBoltProducts.htm
|
|
|
|
|
TonyB3
Apr 2, 2012, 9:46 PM
Post #14 of 16
(9894 views)
Shortcut
Registered: Jan 24, 2011
Posts: 32
|
Ope wrote: Thanks US Navy! mojomonkey I'm sorry you feel this way. Ope.
Don't be swayed by long answers full of regurgitated info gleaned from books. USNavy has absolutely no experience bolting in tufas and any answers he has given you have not come from personal experience with what you describe.
USnavy wrote: I am considering building a crack machine to put up at the local gym to help work on some basic crack climbing technique. Is it even worth building, will it help teach any technique at all? My idea was to read a book about crack climbing then go and practice the locks and techniques taught in the book on the crack machine. Is this a reasonable method of learning before I take a trip to Yosemite and actually try some cracks?
Is this someone who you want to take as the voice of experience?
Other posters have voiced legitimate concerns and provided you with good information. Take anything the sailorboy says with a grain of salt (i.e. ignore it.)
|
|
|
|
|
USnavy
Apr 3, 2012, 1:08 AM
Post #15 of 16
(9854 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
Ope wrote: What's your view of the Fixe Glue In Bolt For 12mm Hole? What bolts do you use? Thanks, Ope.
But as others have said, its best to just scrap this project if you cannot find a solid placement. Just climb it on TR or make it go somewhere else. Its best to avoid bolting tufas period, regardless of the quality of the rock, unless its a really big tufa comprised of solid rock. You should not place any bolt that is within eight inches of any crack or the end of the rock. When you load a bolt, the rock around the bolt is influenced by the load. If there is not enough rock surrounding the bolt, the load is concentrated in a smaller portion of the rock which can result in rock failure and subsequently, bolt failure. This is known to the anchor industry as critical edge spacing distance. Pretty much every manufacturer of expansion bolts has a technical specs page which list the critical edge spacing distance requirements for their bolts and a load reduction table which shows you how much the placement is weakened if you do not meet the edge spacing requirements.
You are going to end up installing a glue in in the tufa and you are going to fall on it, ripping the tufa in half, sending it down the rope with you. Place a bolt up on the roof and hang a long draw off it instead. 
It would also be a lot easier to give advice if we had a picture. You can host the picture here: http://imageshack.us/
(This post was edited by USnavy on Apr 3, 2012, 1:11 AM)
|
|
|
|
|
JimTitt
Apr 16, 2012, 7:13 AM
Post #16 of 16
(9505 views)
Shortcut
Registered: Aug 7, 2008
Posts: 1002
|
Like the guys said, you avoid drilling tufas if at all possible. Even if you get the bolt to hold tufas themselves are unbelievably unreliable and you are just as likely to go down with it which is worse than the bolt failing.
Either drill beside it or if it is a tufa curtain use long bolts, its as easy as that. I´ve resorted to 18" long ones where nothing else would work but you don´t want to do that too often.
And its usual to place more bolts than one would normally use working on the "something might hold" principle.
|
|
|
|
|
|
