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bobbotron
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# Posted: 24 May 2015 11:07pm
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I recently bought a nice 18V cordless rotary hammer. I've used a corded SDS plus rotary hammer in the past so I have some experience with using them. I managed to get a 3/4" bit super stuck in a rock tonight that already had a 5/8" hole in it. Very frustrating, I've had them stuck in the past, but this was unrecoverable, I had to stop before I broke the drill, which was starting to heat up.
I figure there's a better way to get the bits unstuck, I was wondering if any of you fine folk could help give me clues! I tried putting it in reverse, rocking it back and forth, nothing. I'm considering buying a huge plumbers wrench to move the bit - the small vise grips I had wouldn't budge the thing.
In this case, the bit stalled in the same place a few times before really getting stuck - I've read that you can use a hammer and punch to beat out whatever the bit is getting stuck on - any truth to this?
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Littlecooner
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# Posted: 25 May 2015 09:34am - Edited by: Littlecooner
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I think I would use that plumbers "pipe" wrench and would also a "DBH" to see if one could achieve some loosing of the stuck bit. Remember, they are hardened steel so taps with a DBH should move them in one or two directions, then use the pipe wrench and see if you can pull it from the rock. "DBH: = Dang Big Hammer". your DBH could be the typical 2 - 2 1/2 pound "mini" sledge hammer. just how deep in inches is this bit in that 3/4 inch hole? If this is a "regular" drill bit, where a large surface area of the sides of the bit are "stuck" against the side of the rock, I would apply some Kroil or other type of penetrating oil to the bit, in the idea to achieve any reduction in the friction between the steel and rock. Oil, tapping in a 360 degree pattern and a pipe wrench should remove anything you have stuck with a cordless hammer drill.
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bobbotron
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# Posted: 25 May 2015 09:37am
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I have a medium sized sledge hammer and an engineers hammer. I'll try that next time, and I'm pretty optimistic about using a plumbers pipe wrench. I'm going to invest in one and see how that works out.
It's probably only 3" in the hole, but very, very stuck. :P
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bobbotron
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# Posted: 25 May 2015 10:40am
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Ps: it doesn't help that it's black fly season up there at the moment, I sure fed a lot of them while I was messing around with that bit. Doesn't help the concentration on the task at hand!
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Malamute
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# Posted: 26 May 2015 12:22pm
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If you have more bits, have you tried drilling more holes close by around the stuck bit to break up the rock and release the bit?
I havent heard of bits getting stuck in rocks. One real problem is people hitting rebar in concrete and not paying attention and ruining the bit. People that borrow concrete drills are good at that, and are shocked at the price of the bits and that you want them to replace the ones they ruined.
If one knows their tools, its instantly apparent when you hit rebar. It sounds and feels different. To those unfamiliar, its the signal to push harder, especially when forward motion stops.
I'm getting more reluctant to loan tools out, especially the expensive ones. I'll let people hire me to do the job rather than borrow my tools. Often, when they balk at not being allowed to borrow expensive tools, if I tell them how much it costs, and ask if can they afford to replace it immediately of anything happens to it while they have it, they start to see the light.
Got off an a tangent. 
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bobbotron
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# Posted: 26 May 2015 01:17pm
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I did try drilling it out, and took the head off a 3/16" bit when I hit the main bit by accident. :P
Today I bought some nice bosch drill bits, including a 3/4" monster with the cross head on the top. I'll be going back for round two next weekend with a pipe wrench and sledge hammer, see what trouble I can get up to.
Agreed about lending out tools, especially the expensive ones that can get screwed up via untrained operators! I do a good enough job screwing up my tools on my own at times, let alone lending them out. ;)
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Malamute
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# Posted: 26 May 2015 07:34pm
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Yeah, carbide tipped masonry bits are amazing, but dont work real well in steel.
I'm somewhat reluctant to get on board the hammer idea. It isnt the sort of shock the bits are designed for, unless the force is straight down. The twisting with the wrench also concerns me, but I guess you have to try something. The bit isnt very useful where it is.
Drilling around it seems the least scary to me, but I've been mistaken before.
Good luck!
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LastOutlaw
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# Posted: 26 May 2015 07:37pm
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I wonder if you could heat the bit then let it cool. It would expand while hot then shrink once cool and might help loosen it.
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bobbotron
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# Posted: 26 May 2015 07:51pm - Edited by: bobbotron
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Quoting: Malamute I'm somewhat reluctant to get on board the hammer idea. It isnt the sort of shock the bits are designed for, unless the force is straight down. The twisting with the wrench also concerns me, but I guess you have to try something. The bit isnt very useful where it is.
Yeah, I'm going to try the wrench first. It'll probably be hard on the bit, but like you say, I've got to try something.
I'm pretty well prepared for the weekend, I just bought an all steel 18" pipe wrench, some more bits and a steel punch, I hope they'll do the trick.
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JJHess
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# Posted: 26 May 2015 09:15pm
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I've removed them with the pipe wrench before. Just get it on securely and counter-rotate.
Forget the hammer. If you screw up the end of the bit at all you'll ruin it.
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cabinbiscuits
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# Posted: 28 May 2015 03:39am
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If you can use a small compressor and air chuck to blow the grit and powder out of the hole from around the bit before you try to couterrotate it, I think that would help you.
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OwenChristensen
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# Posted: 29 May 2015 09:58pm
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Yes, blow air into the whole while bumping it.
Owen
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bobbotron
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# Posted: 31 May 2015 10:11pm
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Too far away from the cabin to get compressed air down there. Unless I filled up the compressor and then walked it down the hill.
I ended up drilling another hole nearby. I used a new bit, the other 3/4" one is still in the hole, it took forever to get the big pipe wrench to grab the bit, and then I couldn't move it. Perhaps it will become a feature of the property. :P
I've changed my drilling technique. Up till this point, if I wanted to drill a large hole, I'd drill a smaller diameter one, and work my way up in bits. I've found that the likely hood of the larger bit getting stuck is way higher doing this. For the last few holes I just drilled 3/4" straight from the get go - it actually went fairly quickly and no jammed bits!
Managed to use up some expanding wedge anchors for bracing something to a rock. I have a bunch lying around that didn't get used for another project. Holy cow they're great, seriously solid!
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eliotgoldfinger
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# Posted: 2 Aug 2017 03:03pm
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I too have been drilling progressively larger holes in bedrock to get to a 7/8" hole using a Hilti hammer drill. A bit got stuck in a previously drilled smaller hole. I figured out that I couldn't rotate it out, or move it side to side, but that I needed to pull it straight out. I couldn't grab it and pull with enough force, but if I could get a secure collar around the bit, I could use a crowbar and pry it straight up. I have only 2 vice grips, and secured them both, as tight as I could, in contact with each other, around the bit very close to the rock surface, but left enough space to get the flat end of the crowbar in. The bit came out very easily when I pried it up. The trick is to make the vice grips as tight as possible so they don't slide up the bit when you pry with the crowbar. If I had 4 vice grips, I would have used them all. The bit came out undamaged. Hope this works for you.
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bobbotron
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# Posted: 2 Aug 2017 05:59pm
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Hey Eliot, I'll have to try that! The bit has been in the rock since 2015, doesn't hurt to give it another go.
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Elisha
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# Posted: 4 Jun 2018 05:55am
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I use it with 18 "wood or magnet bits, drywall, foam, top plate, brick mortar, using drill drill from 1/4" to 1/2 "hole. I used it to pilot the hole drill and 1/2 "x 2 - 3" log bolt drive. I installed it in a plastic anchor and screw it on the brick to use 3/16 "hole drill in a mortar.The chalk tool is less and I think it's 3/8 "chalk. I'm looking for a drill and bit that can be more powerful and that I stand to use to give it
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Borrego
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# Posted: 4 Jun 2018 10:21am
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Put a chipping hammer bit in the tool and chip around the old drill bit.....
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KinAlberta
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# Posted: 4 Jun 2018 12:25pm
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Would a can of freezing spray help at all in these cases?
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