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Brutus of Wyde
climber
Old Climbers' Home, Oakland CA
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Zeemac rivets. And don't fall.
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Steve Grossman
Trad climber
Seattle, WA
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Hey JB- Didn't mean to be too hard on your hardware! If the taperbolts that you have are stainless steel and of recent manufacture then that would cover most of my concerns based on the design 20+ years ago. One handed installation is a big plus but I've gotten used to the side hammer jab to set the Powers variety. The big advantage of the Taperbolt design is full bolt diameter to match hole size. The Powers design loses hole diameter to the outer shield. As long as you torque to specification you should remain golden.
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bachar
Trad climber
Mammoth Lakes, CA
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Topic Author's Reply - May 8, 2007 - 10:08pm PT
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Darryl Cramer - yeah, those Hilti bolts look interesting. I went to the website but couldn't find any specs on strength. What kind of specs does the 3/8" x 3" bolt have? (pullout and shear). Have you ever placed any 3/8" ones?
Steve - Thanx for the slack. I still have concerns about ANY bolt so I do like to hear what others think - especially if they can find a fatal flaw in the system. When I first saw the Taper bolt I also couldn't believe it would be any good. After testing them I'd say they are pretty bomber however and they've withstood the test of time (20 years time anyway).
Steve - On another note - how is it drilling a 1/2" inch hole as opposed to a 3/8" hole? On the lead???
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Clint Cummins
Trad climber
SF Bay area, CA
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Darryl,
Amazing numbers for tensile on those coil taperbolts. I keep thinking it is only the thread depth that is holding, but really it is several threads holding in parallel. Of course in shear they can't be beaten. Too bad they do not seem to be available in stainless.
For good granite new routes I have been using 3/8" x 2.25" Stainless Steel wedge bolts, mainly because they are SS and cheap (under $1 each). They could be placed with one hand, but a hammer is needed. The "thread depth" relative to the coil taper bolt looks nicer, although the surface area of that one right is not too large. In shear they are a little weaker, since the hanger is on the threads. The nut can loosen as well. And they cannot be easily removed.
For softer rock, I use the Powers 5-piece. The sheath and threaded cone give superior surface area contact. ASCA uses these in SS for replacement. SS is about 5x more expensive, unfortunately. They also generally take 2 hands and a hammer to place.
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bachar
Trad climber
Mammoth Lakes, CA
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Topic Author's Reply - May 9, 2007 - 10:17am PT
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Darryl - Yes those specs do look good - stronger than the Taper Bolt. It's hard to believe Hilti doesn't have a stainless version - they usually have some of the best stuff out there quality wise.
Edit: Any links for the Powers 5-piece?
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Steve Grossman
Trad climber
Seattle, WA
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JB- I am assuming that you are hand drilling these holes. If so, expect to take about half again as long. My personal record for drilling 3/8" holes on tough stances is about six or seven. Sounds like the smaller hole size would make for a less hellish outing for you. Most of my drilling these days is maintenance related rather than new projects but I generally hand drill all of the 1/2" hole that I fill. It helps to have been swinging a hammer for thirty years!
Clint- My big concern with the Thunderstud type, collar and cone end bolt design is the amount of fatigue left behind by the threading during manufacture. Whenever a solid rod is threaded, considerable cross shearing due to applied torque is present. The area at greatest risk is the threading termination point which is usually exactly where the force is applied under load during normal installation. You have a 3/8" solid bolt but the design is such that it is effectively reduced to 1/4" and you are loading the most tortured area of the metal. Couple that with being forced to trust your whole show to the dainty little dimpled lock collar and I won't use them. Upping the size to 1/2" gives you more beef and much less chance of material failure due to stress flaws. I also have a problem in principle with a bolt design the tightens in the same directional mode as it would fail. Cheapness is the only plus here IMO.
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Howie
Trad climber
Calgary, Alberta
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Steve, what type of threading are you refering to with regards to cross shearing?
Howie.
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Steve Grossman
Trad climber
Seattle, WA
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I am referring to twist shearing due to the torque introduced during the threading process. Small diameter lag bolts suffer from the same sort of weakness and will often shear off right at the thread termination. I don't rely on lags in my contracting work either.
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the kid
Trad climber
fayetteville, wv
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bachar, different bolts work best in different types of rock, so there is no end all perfect bolt for each route.
I agree with grossman, stainless is the only way to go for long term anchors! sorry to say in my dirt bag days of rifle and potrero i could only afford non stainless...
i have always liked the 5 piece rawls but here at the new the rock is too hard to place these. they screw up a ton when you pound them in before tighting...
so we use standard screw top type stainless rawls..
now for slab, vert to mildly overhanging hard rock like granite and new river sand stone- the petzl long life is the bes there is- stainless, easy to place as it is pound in the pin bolt...
but when it gets steep these are not the best option...
i think those tapers were better than 1/4 rawls back in the day, but now there are better options for the power drill...
ks
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slobmonster
Trad climber
berkeley, ca
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I don't think I'm personally familiar with the Taper Bolts; the only thing I've seen that look familiar are those f-ed up Petzl "self-drive" jobbies that were popular in some areas.
One simple question: are they (at all) removeable? Though it's tricky, one can yank a Rawl/Powers 6-piece, enabling replacement using the same hole...
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bachar
Trad climber
Mammoth Lakes, CA
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Topic Author's Reply - May 9, 2007 - 02:45pm PT
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slobmonster - yes they are removable too.
Kurt - the 3/8" is insanely better than 1/4" we used to place. Check out the link at the start of the thread for specs.
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Off White
climber
Tenino, WA
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Kurt - The New, while hard, is a sandstone, right? I've had problems with the Powers 5 piece bolts in the softer sandstone on my home crag, but the issue seems to be the little plastic cap on the cone coming off and the gritty sandstone debris clogging the threads - the bolt just keeps spinning rather than tightening up.
If that's the problem you're experiencing, the fix Steve turned me on to may work for you as well: before pounding in the bolt, pull the cap and fill the cone with a spitwad. Not that stuffing a small wad of toilet paper into a possibly dry mouth is any fun, but I haven't had any problems since I took up the practice.
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slobmonster
Trad climber
berkeley, ca
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Re: Rawl/Powers 6-piece bolts:
I make a habit of progressively hand-tightening the hanger as I tap in the bolt. This can help keep the cone from spinning off.
If you do end up with a spinner, clip a draw to the hanger, and pull straight out as you attempt to tighten it. This can sometimes allow you to re-acquire the cone.
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Clint Cummins
Trad climber
SF Bay area, CA
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Steve,
Yes, the cheaper wedge type bolts (cone and ring) are weakened by the standard method of cutting the threads. Tom Addison has explained this to me as well. He recommended for this type of bolt to use one where the threads are milled instead of being cut (such as the Petzls). Still I think the strength numbers are much better than 1/4". And I agree, their main reason for use is cheap SS. My excuse at present is that I use them on obscure new routes. I wouldn't use them for rebolting. I also agree that the "dimply ring" on the wedge bolts is not good for soft rock - too little surface area. It should be fine on good (hard) granite, though.
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Mark Hanna
climber
Seattle, WA
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Hi All-
I am Darryl Cramers friend who uses the Hilti HCA Coil anchors. I have been using them in compact granite since about 2001, and in industrial settings (temporary worker fall protection anchorage)since about 1995. Over this time I have set approximately 500 of these in 3/8" and 1/2" configurations. I also have a pull test setup, and have proof tested many in concrete (several in granite). Some of the benefits I have recognized are as follows:
1)Ease of removability- 100% removal of the bolt (including coil) is as simple as backing the threads out until the initial thread is engaged, then applying a prying force to the bolt with claw hammer or crow bar (protecting stone of course). The result is a clean hole, with no monkeying around with end cones or sleeves in the bore. I have done ground up routes using these, and during rappel outfitted with glue-ins during the same day.
2) Ease of inspection- As a direct result of #1, the bolt shank can be inspected in about 30 seconds, and is returned to service without any worry of cross threading due to the large thread pattern. During several cycles of removal and inspection of routes I have put these on, they appear to be weathering well, and showing minimal corrosion or degradation.
3) Strength- In granite, this anchor performs well with dynamic loads, freeze thaw ice wedging and subsequent nut loosening (wedge anchors prone to this around here), and is full diameter Grade 5 steel. In 1/2 " size, the shear goes up to about 23000 lbs for a 3" embed. relative strength approaches that of epoxy anchors for bore size.
4) Predictability- I have never had a spinner (during or long after install) when these are properly installed with a reasonably clean bore that is of appropriate depth. I feel that this setup is no more prone to failure than other systems when installed according to manufacturer's instructions. Let's face it- all anchors that could be called into service in this way need to be installed well and by qualified individuals. Grade 5 steel also corrodes in a relatively predicatable fashion. I am somewhat concerned that the current trend in our area of 3/8" SS wedgies will someday be a difficult to remove setup that may harbor undetected corrosion. We used to think buttonheads were the answer...
While there may be no perfect anchor for every situation, I think this one has many benefits that work well for higher compressive strength rock. In an attempt to minimize galvanic corrosion between SS hanger and HCA, I use a stiff nylon washer under the bolt head. This seems to help considerably.
I will be inspecting several routes soon, and will post pics if anyone is interested.
MH
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Off White
climber
Tenino, WA
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May 10, 2007 - 12:01am PT
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Mark - Have you used those bolts in the sandstone conglomerate on Big Four?
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