Author Topic: Is it possible to core-out 3/8" stud type bolts?  (Read 3697 times)

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Offline Mr.

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Is it possible to core-out 3/8" stud type bolts?
« on: January 26, 2012, 01:11:22 pm »
Can something like this be used to drill out bad studs bolts? Could a drill bit be adapted for use on hand held hammer drill? Might apply to some high traffic sport walls/accessible areas. Be sweet to not have to carry a generator or water tank... It seems like a good idea if it works.

http://stores.toolsdirectusa.com/-strse-Diamond-Core-Bits--dsh--Wet-cln-Concrete--dsh--Short-Bit/Categories.bok
http://stores.toolsdirectusa.com/-strse-Core-Drills-cln-Hand-Held/Categories.bok

skully

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #1 on: January 26, 2012, 04:43:19 pm »
I imagine you could, though a diamond core bit will gum up in metal. They're made to cut stone(very hard, rather brittle) so metal is a bit soft.
Also, the smaller the diameter, the faster it will get hot. They get BAD HOT! If it gets too hot, your bit will disintegrate. The smaller ones aren't hollow, either. 3/8ths is a solid bit. too small for a real core.
I run a 1 3/8" core bit for drilling faucet holes(on a Makita variable speed grinder). Alpha bits are the workhorses.
« Last Edit: January 26, 2012, 05:26:51 pm by skully »

Offline tolman_paul

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #2 on: February 13, 2012, 04:03:54 pm »
I don't see why a core drill wouldn't work if you could find a 1/2" od 3/8" id bit.  The trouble is it'll have to be run by a power drill.  Core bits are not percussive bits.  They are really a circular saw.  Unless you were a glutton for punishment core drills just aren't practical.

Pull the stud out as far as possible, either break it off through fatique failure (bend it back and forth) or cut it off with a cold chissel.  Then drive the remaining stud back in the hole with a center punch, patch the whole and drill a new hole for a new bolt.

Offline *Mucci*

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #3 on: February 13, 2012, 08:29:13 pm »
My buddy made a stud bolt puller.  Pulled at least a dozen or so.

It is about the size of a half a snickers bar.

Use a regular power drill, with 17/64ths HSS bit, drill out the core, pull the remaining metal out with small hook tool and or needle nose plyer.

Way easy, provided you can use a 18v/24v cordless drill where you are doing the removal.

Mr. I sent you a message with a bit more info.


Offline *Mucci*

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #4 on: February 13, 2012, 08:35:57 pm »
These are for sale, message me for pricing.




As a good friend once said, "the only thing easier than placing a bolt, is chopping one"

Offline Greg German

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #5 on: February 14, 2012, 03:54:35 pm »
Anybody have any experience with this sort of tool?:

http://www.drillcogroup.com/removal.html

Now expansion anchors may be quickly and easily removed and replaced without the need to take down existing attachments or to provide temporary supports. Drillco's ultra thin wall Bolt Extractors? overdrill the existing expansion anchor and leave a resulting hole sized to accept a replacement anchor only 1/8" larger than the one removed. For example, a 1/2" wedge bolt may be drilled out and a 5/8" wedge bolt substituted in its place. Or, a wedge bolt may be drilled out and replaced with a Drillco Maxi-Bolt? all in one easy operation. Since the existing anchors are drilled out, no concrete spalling results from the replacement process. Drillco Plate Cutters? are used to provide the proper hole size in the attachment.

Offline cobbledik

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #6 on: February 14, 2012, 04:10:11 pm »
How's that work Mucci?
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline Mr.

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #7 on: February 14, 2012, 08:10:51 pm »
Greg: great find! thanks. looking into this.

Mucci: how does it work? torque it till it pulls? looks promising because its portable.

thanks everyone. good stuff.

Offline *Mucci*

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #8 on: February 14, 2012, 08:41:23 pm »
Hey sweet there is some interest!

Basically, this thing threads on the stud you want to remove.  If the threads are a bit nicked, a file can be used to smooth the damage to the male thread the device is going on.  If the threads are FUBAR, just torque it and patch it.

You then use a High Speed Steel/cobalt etc.. bit to drill out the core of the bolt.  The puller is more of a guide for the bit.  A 3/8" stud is more like 5/16th if you exclude the threads.  So you drill out the core, then snap the stud off, and either funk out the remaining metal with a tool My friend made, or use your own fabed tool to pick out the metal.

Pretty easy, and I have seen the results up close and personal.

I have put the word in and we will see if/when he can crank a few out with directions!

Offline Mike.

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #9 on: February 15, 2012, 09:52:21 am »
Mucci, nice work. Looks like the tool could be useful even without drilling?like you could crank it down tight and continue tightening to get the stud spinning/loose.
Say no to limbers, excavators and retro-bolters. No matter how much he smiles.

Offline Greg German

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #10 on: March 20, 2012, 07:30:03 am »
Bumpitty bump.

Have any of you tried using a hydraulic punch driver as a stud puller?

Harbor Freight sells this one for $99. It has 3/4" and 3/8" threaded studs for the dies.
A coupler nut could connect it to the threaded stud in the rock...
http://www.harborfreight.com/hydraulic-punch-driver-kit-96718.html

A- Which bolt types are more likely to come out than break with this method?
B-  Do you think it would be any more successful than a tuning fork for 1/4" bolts?

Here's a video of a more expensive one in action.
KuDos? Hydraulic Power Puncher PNST-10



Offline mungeclimber

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #12 on: May 02, 2012, 07:02:31 pm »
that remover is awesome!!!  portable



Offline Greg German

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #13 on: May 03, 2012, 01:42:46 pm »
It's still heavy, but it's portable and relatively cheap. Greenlee makes one that is more compact, but it retails for ~$900.
We still need to do some field testing in the vertical world, but this looks like it could potentially make a lot of bolt holes re-usable.

Offline Greg German

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #14 on: November 10, 2013, 10:56:03 am »
Bump from long ago, but it's a related update:

https://www.youtube.com/watch?v=IRA9aFefsxY

The punch driver can work very effectively on rusty studs.
Carry on.
-gg

Offline Greg German

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Re: Is it possible to core-out 3/8" stud type bolts?
« Reply #15 on: March 07, 2014, 12:41:55 pm »
Food for thought - New methods of bolt removal.
The Action Committee for Eldorado has been getting pretty good results re-equipping routes using the same holes. The hydraulic thing works great, but we're also working on less expensive solutions for developers to use.

Forged eyebolt + funkness + SDS bolt spinner = stud removal

Proof of concept -  https://www.youtube.com/watch?v=csJXmXBi2e0
In the field - https://www.youtube.com/watch?v=CHVq5Dq-OMY

I turned a cheap 4 lb. hammer into a 3 lb. hammer to create a MonsterFunker. I modified it using 10" fiber cut-off wheel on a ShopSmith (essentially a horizontal drill press.) Drilling the hole through a hardened steel hammerhead isn't easy, and in finding a solution I discovered a useful tool for bolt removal. I burned up several allegedly sharp/hardened bits in failed attempts before I modified a cheap carbide-tipped masonry bit to do the job. I used a Dremel and a diamond barrel to re-shape the carbide (eyeballing it - took 10 minutes.) It plowed through the hammer like nothing else would. I modified a 3/8" one and used it to make metal pulp of the remainder from the stud bolt on Athlete's Feat that broke off in the hole. The bits came from Harbor Freight for < $0.99/each.