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Banquo
climber
Amerricka
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Topic Author's Original Post - Oct 18, 2015 - 04:44pm PT
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In the past I have tried pulling on bolts until they break and then fishing out the sleeve and wedge.
http://www.supertopo.com/climbers-forum/1268908/Pulling-a-Wedgie
I have also tried to drill out the bolt with a ˝” diamond hole saw. Note that a standard hole saw might also work but I have never seen a ˝” one.
http://www.supertopo.com/climbing/thread.php?topic_id=1306518&msg=1306518#msg1306518
Neither of those approaches is practical.
The best method I have seen so far is spinning the bolt in the hole until a groove is worn in the wedge. The groove lifts out the sleeve when you pull the bolt. This method requires a power drill so cannot be used in National Parks or Wilderness areas.
http://www.mountainproject.com/v/inexpensive-bolt-extractor/109487927
I decided to see if I could make a ˝” impact core drill that could be used to drill down past the sleeve until the whole assembly can be lifted out. If the drill is the right outside diameter, a ˝” bolt can be placed. According to the ANSI standard B212.15 the outside diameter of the bit should be between 0.520 and 0.530 inches. The inside diameter should just fit over the bolt so that the bolt guides the bit. I decided on a stepped inside diameter with a main portion 0.380” to fit a 3/8” bolt and 0.390” near the tip to be sure and fit over the sleeve. For comparison, the ANSI diameter for 3/8” drills is 0.390 to 0.398 inch. What I ended up with is essentially a ˝” steel hole saw with a very deep socket.
A very hard, tough and wear resistant steel is required since I don’t have the tools or skills required to work with carbide. (Carbide is more correctly referred to as "tungsten carbide" and is more of a composite than an alloy. Carbide tools contain materials other than or in addition to tungsten carbide.) Since carbide is not an option right now, I decided to go with a tool steel. There are hundreds of different steel alloys referred to as tool steels.
High speed steel (HSS) is a class of tool steels that was developed to hold its temper at high temperatures. Since it can get hot without losing hardness, you can cut and drill faster with tools made from it hence the reference to high speed. HSS steel is troublesome to harden and temper. Before hardening by quenching, the various types of HSS usually need to be brought up to temperature in careful steps and then quenched in water, oil or air depending on the type. Tempering generally needs to be done several times. Other types of tool steel are generally simpler to heat treat but it depends on the type.
As a first try I decided to use what I have in the garage. The only piece of tool steel on hand was a length of ˝” diameter drill rod I had bought it to make a reamer to form A-Taper drill holder sockets. It is type O1 (An “oh” not a “zero”) which is an oil quenched steel. O1 steel is easy to machine and heat treat but does not have the best wear resistance. I figured it was good enough for development purposes. I shaped the bit on the lathe and since I couldn’t think of a handier way, I shaped the cutting teeth with a triangular file. I then heated only the cutting end up to cherry red with a torch and quenched it in oil. Just to see if fully hard would work, I didn’t temper it. I set a bolt and started hammering the bit. It lasted a dozen or so blows and the tip shattered. It did seem to have been working though.
The second try I did pretty much the same but tempered the steel down to what I figured would be about R55 (325° C). The drill worked very well until the outer edge of the teeth wore down which left the tip of the drill beveled causing it to jamb tightly in the hole. I did get about ˝” deep without much trouble and it was going very well while it went.
So, I need to find better steel with very good wear resistance or find somebody who can fabricate carbide. Looking through the various types of tool steel, I have found two that appear to have good properties, M4 and A11. A11 is also known as CPM 10V.
M4 is a tool steel and requires careful heat treating as described above. A 5/8” x 36” piece with shipping runs about $300 on Ebay. Choose 5/8” so it can be turned down to 0.530”.
A11 has simpler heat steps but due to problems with decarburization (loss of carbon from the steel), it should be heat treated in a molten salt bath to isolate it from oxygen. Fooling around with molten salt in the garage sounds like something I’d rather not do. A11 is harder to find but costs about the same as M4. www.hudsontoolsteel.com
Since I don’t feel like spending the money to continue, I have stopped work for now.
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Mungeclimber
Trad climber
Nothing creative to say
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Oct 18, 2015 - 06:43pm PT
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if you make the half inch hole, then you have either:
1. Use the hole and back fill with a half inch bolt in the case of replacing.
or
2. Epoxy the hole with camouflage rock dust to fill the hole to prevent it from being reused with a larger bolt in the case of restoration efforts (I.e. fixing retrobolts)
neither is relevant to your problem, just thinking out loud.
Have you talked to John G about this? Or perhaps AROCA? There are ways, without a motoroto.
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Juan Maderita
Trad climber
"OBcean" San Diego, CA
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Oct 18, 2015 - 06:46pm PT
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Very cool Banquo. Always the innovator and willing to put the time into it.
Has anyone ever tried using an "eggbeater" type hand drill with a diamond core drill? Is mechanized, not motorized, acceptable in wilderness? Diamond core drilling would also need a water spray bottle.
http://www.garrettwade.com/beautiful-german-made-hand-drills-gp.html
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Clint Cummins
Trad climber
SF Bay area, CA
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Oct 18, 2015 - 07:44pm PT
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Interesting approach.
The teeth should hold up longer in non-granite rock like at the Pinnacles.
But the rounded edges and binding is familiar from the days of drill bits without tungsten carbide tip inserts.
Munge,
If one is just chopping a 3/8", you can just break the top of the bolt off by torquing very hard on the nut (long handled wrench or breaker bar).
Or you can use washers/spacers and often break it at the wedge down in the hole.
(Not suitable for replacing in the same hole, though, as Banquo has shown it's hard to get the wedge/cone out).
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Banquo
climber
Amerricka
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Topic Author's Reply - Oct 18, 2015 - 08:31pm PT
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There are ways, without a motoroto.
Munge, post some details. I like to learn about things. BTW, if you are ever headed out for moderate climbing, or even a photography trip, let me know. I've lots of free time these days.
Have you looked at carborundum hole saws?
Please, please provide a link to where such things are available. As I said above, I have not been able to locate 1/2" hole saws of any sort but have located 1/2" diamond core drills. I have, as an experiment, tried drilling holes with a common, bi-metal hole saw by pounding on it with a hammer and found that they drill okay -- but, I can't find them in 1/2" and, they are not long enough to drill out a standard bolt. Carborundum is an abrasive and not as good of an abrasive as the diamond that I have already tried - again, please provide some background and I will be happily surprised to find another material to consider. I like input but please do a little background research before you post. If you can come up with something useful, I will reward you with praise and free custom gear.
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cragnshag
Social climber
san joser
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Oct 18, 2015 - 08:32pm PT
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I think you should try the molten salt bath. I heard it's good for the skin. When you are done Gus can use it for a salt lick.
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MisterE
Gym climber
Being In Sierra Happy Of Place
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Oct 18, 2015 - 08:33pm PT
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The links here and the info is so good.
Thanks, all - for your R & D.
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Greggonator
Trad climber
Broomfield, CO
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Oct 19, 2015 - 05:24am PT
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The diamond hole saws are very fragile. We broke several of them during our tests (at ~$60.00 a pop). The cutter head would break off if the bit overheats or if it binds up on the bolt. The size bit we had removed about 0.015" of metal off the threads of the stud.
The short length of all the commercially available ones was also an issue.
The spinning technique has worked very well for me. Really rusty Redhead style wedges can be pulled with the Doodad tool without spinning - The rust disables the collar and it is essentially a nail instead of a mechanical bolt.
With that style of wedge, I think that if you could keep 10 or 20 lbs of outward pressure on the bolt while turning it a few revolutions (even without a power drill) it might damage the wedge enough to pull it out without breaking (when it's already rusty). The collar has a squared off leading edge. KB3's have a tapered leading edge and take a lot of high-speed spinning before they give up the fight.
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Banquo
climber
Amerricka
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Topic Author's Reply - Oct 19, 2015 - 09:15am PT
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I think you should try the molten salt bath.
Sure Bob! Bring the kids over and we'll have fun melting sodium chloride. It melts at 801 °C (1,474 °F). I wonder what happens if you throw water into it.
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Mungeclimber
Trad climber
Nothing creative to say
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Oct 19, 2015 - 09:27am PT
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thx Clint! Admittedly, I have a very small crowbar. I didn't have much luck with a 3/8 split shaft and stopped trying to do wedgies for a long while. In the harder rock, it doesn't beat the heck out of the rock?
huffing salts?
I think that's an explosive idea!!
Dan, you got it. That's all I'm doing right now while the shoulder gets back. Took the shoulder out for a spin and the inflammation is back. But going to Pinns for Kalen's gig and Pinns appreciation days. You going?
Plus I got some weekends in November up on SPH.
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Scylax
Trad climber
Idaho
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Oct 19, 2015 - 10:48am PT
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I confess that I would much rather read a thread about bolt removal instead of bolting(dumbing down) routes!!!
Also, looks like nice work there.
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Banquo
climber
Amerricka
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Topic Author's Reply - Oct 19, 2015 - 11:15am PT
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Scylax -
Don't click on those threads, your brain will rot and you will begin to spout gibberish.
Munge -
1) I have not shown this to John G
2) I don't know what AROCA is.
3) I did not sign up for Pinnacles Appreciation days which I believe is this weekend.
4) I don't know what Kalen's gig is.
5) If you head up to SPH and need somebody to drink your beer, send me an email and I might tag along.
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Banquo
climber
Amerricka
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Topic Author's Reply - Oct 20, 2015 - 09:56am PT
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Since I already had the two bits, I decided to try again. I annealed them, cut off the ends and filed new teeth. The first bit that I tested without tempering had long teeth so I decided to try an non-tempered bit with short teeth and see if it worked better.
First I tried to continue the hole I had started but the walls were slightly tapered from the earlier bits and it simply stuck. So I started a new hole without a bolt and It drilled pretty well for about 3/8" when the teeth started to go. A couple teeth broke off and the inside face of others chipped off. Since the bits are straight sided, binding was an issue.
Second try I cut teeth and then turned down the outside diameter above the teeth in hopes of reducing binding. This left a small edge which probably caused stress concentration. I placed a new bolt and tried to drill around it but the teeth broke off pretty fast.
So far I think to work a bit needs to have teeth with some outward set to reduce binding. A better material than O-1 tools steel is required.
A real problem is that as you drill down along a bolt you are chipping off the edge of the hole, the edge chips off inward causing a taper to the hole which binds the bit and breaks the teeth off inward.
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Banquo
climber
Amerricka
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Topic Author's Reply - Oct 23, 2015 - 01:50pm PT
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So I have decided the hollow drill approach isn't practical with the materials that I work with. I also think the bits wouldn't last even with the best of steels.
Back the the spinner method. I made a hand crank bolt spinner. It isn't a practical version but I simply used what i had in the garage. The spinner crank is simply a box end wrench with a kludged handle. The connector to the anchor bolt is a 3/8" coupler nut, bolt and jamb nut. A piece of flat plate was used to apply tension to the bolt while turning. The puller is the one I used in the earlier thread (linked at the top of this thread). All the equipment can be improved for weight and portability but this was just a feasibility check. Lots of ways to improve this rig.
1) Remove hanger.
2) gently knock in bolt until just loose.
3)Place pry plate over bolt.
4) Screw on coupler nut until it almost draws tight.
5) Screw bolt into coupler until it locks against anchor bolt.
6) Tighten jamb nut.
7) Crank while keeping tension on the bolt. It is not possible in this lifetime to crank for too long.
8) Remove crank, coupler, bolt and nut.
9) Attach puller and apply as much tension as you can without breaking the bolt.
10) Loosen puller, knock the bolt back in and pull again.
11) Repeat 10 as desired.
12) repeat 1 through 11 as required.
13 Have lunch
14) repeat 1 through 12.
Actually, this took less than an hour but it seemed longer. I didn't really make a groove in the wedge that would lift out the sleeve but I did gouge up the surface which I think helped. The bolt would probably, eventually come out if you just kept pulling on it and knocking it back in.
the main things that might go wrong are breaking the bolt, bending the bolt or buggering up the threads.
I don't know how this will work with rusty bolts. The redhead bolts I used have a stainless sleeve and a carbon steel wedge. The stainless is probably softer than the carbon so the creation of a groove might never happen. There are so many types of wedge bolts, in varying condition, success will probably be highly variable. You can always try and if it doesn't work, chop and patch.
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bhilden
Trad climber
Mountain View, CA/Boulder, CO
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Oct 23, 2015 - 07:59pm PT
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Dan,
so step #7 in your method is similar to Greg German's (Gregger Man) spinning the bolt with a power drill in an attempt to score the cone shaft so the cone will not ride down the bolt when tightened. Next, try to pull the bolt out and hope the cone won't move and expand.
Cool! There may be a project at the Pinnacles with your name on it!
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looks easy from here
climber
Ben Lomond, CA
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Oct 26, 2015 - 10:55am PT
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Sure Bob! Bring the kids over and we'll have fun melting sodium chloride. It melts at 801 °C (1,474 °F). I wonder what happens if you throw water into it.
What? You're scared of making a little literal lava in your garage? What could go wrong?
[Click to View YouTube Video]
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grubs
climber
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Oct 26, 2015 - 11:37am PT
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Banquo thanks for the continued efforts and good info.
I have also played with the diamond core drill method, and even ordered a custom bit of exactly the right dimensions to fit around a 3/8" wedge bolt. I used a 1-gallon garden sprayer adapted to the core drill for cooling. The first bolt I tried came out like a charm, and I drilled the remaining hole to 1/2" and put a new bolt in. However, things went downhill from there and I eventually abandoned the method for these reasons:
1. The diamond bit did not track down the shaft of the bolt like I expected, instead it was very happy to cut right through the steel bolt. If my entry angle was off even by a tiny bit, I would be cuttin way into the bolt by the time I got to the end of it, leaving an unusable oddly shaped hole.
2. After about 3 holes, the diamond bit was very worn and could no longer efficiently drill holes, possibly because two of those holes involved drilling through the steel bolts due to a poor entry angle as mentioned above.
3. The custom diamond core drill cost me about $100. This might be acceptable if it removed 100 bolts before wearing out, but that didn't happen for me.
4. It was very awkward with the water cooling rig, and a gallon of water runs out quick.
I know some have found success with this method, but after giving it my best shot I agree with your conclusion that for most of us the diamond core drill method simply isn't practical.
I've moved on to the spinning and pulling method that has seen so much success lately (that is, where power drills are allowed). My problem here has been finding coupling nuts to couple the 3/8" bolts to my drill and to my hydraulic punch driver. Do you have any recommendations or do you tap your own coupling nuts? McMaster-Carr didn't seem to have what I need.
Anyways, thanks again for the continued R&D and for sharing your experiences.
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Brian in SLC
Social climber
Salt Lake City, UT
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Oct 26, 2015 - 11:49am PT
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I've always wondered, in areas where you couldn't use a power drill, if you could use something along the lines of a yankee screwdriver to spin a bolt...?
Interesting methods!
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Rosamond
Trad climber
Truckee, CA
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Oct 26, 2015 - 11:55am PT
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Nitric acid eats metal. Instead of going through all this mechanical rigamarole, has anyone tried simply dripping a couple milliliters of nitric acid into the system, coming back a week later, and removing the now heavily corroded bolt? Of course, Nitric acid also eats things like climbing gear, so you'd have to be careful.
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