Removing Bolts with a Grinder

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 muppetfilter 20 Jul 2020

I've just come across the BMC bolting videos and the Grinder one and it seems a bit odd... Why wouldn't you use a bolt puller to remove an expansion bolt rather than use a grinder with a slitting disc then paste the rock with a hammer rather than use a punch? This will do much more damage to the rock than winding the bolt out with a puller. There are several technical safety issues  that aren't good to show in an instructional video either.

youtube.com/watch?v=609rzF0WBqo&

 jimtitt 20 Jul 2020
In reply to muppetfilter:

Normally the bolt fails before it pulls out so lugging an expensive and heavy hydraulic puller becomes a pain in the ass. If it's a wedge bolt you might be able to spin it first then pull it, loads of info on this on Mountain Project.

 remus Global Crag Moderator 20 Jul 2020
In reply to muppetfilter:

I'd guess it's partly about keeping the video short and easy to understand. Although it might not be optimal in every case an angle grinder is going to work reasonably well on most types of bolts and in most situations.

2
OP muppetfilter 20 Jul 2020
In reply to jimtitt:

we just use a bit of scaff pole to create a bride, long suspended ceiling nut, thread bar with a plate and nut on top then spanner to take bolts out of concrete at work. Its a lot cheaper than a hydrajaws and the geordies are less likely to steal it.

4
 jimtitt 20 Jul 2020
In reply to muppetfilter:

You can pull them straight out with a 7 ton excavator as well but that's also hardly relevant.

4
 Rick Graham 20 Jul 2020
In reply to muppetfilter:

I find it easiest to use a quiet stealth technique. Use a chisel to put a slight notch each side of the bolt as close to the rock as possible . Put a  piece of metal tube over the stud head and flex it both ways until it cracks through. Tap the residue into the old hole so it is flush.

Takes at least a minute for each bolt

Do try a puller first but not always practical like Jim states .

Post edited at 18:45
OP muppetfilter 20 Jul 2020
In reply to jimtitt:

Thank you so much for your helpful  reply,  Its quite relevant as the BMC  has produce a video that shows someone without the correct PPE  hazardously handling a powertool while at height. 

Have you wondered why you don't change disks with the battery attached and why you don't use damaged discs or cutting discs to grind with.

11
 webbo 20 Jul 2020
In reply to muppetfilter:

Heading out to Attermire

2
 jimtitt 20 Jul 2020
In reply to muppetfilter:

Why are you telling me what someone else should do?

5
 GPN 20 Jul 2020
In reply to muppetfilter:

Suggest you contact the BMC directly. You’re right that the video shows numerous things that are poor practice (e.g. using a damaged blade).

Post edited at 21:22
 Enty 21 Jul 2020
In reply to muppetfilter:

What a crap way of doing it

E

 spenser 21 Jul 2020
In reply to muppetfilter:

I'm not overly hot on the use of angle grinders for the use of removing bolts but am a member of the Technical Committee, I'll pass this onto the chair and the technical officer (I think Dan may still be furloughed, not 100% sure).

Cheers

Spenser

P.S. I'm sure the geordies will find a good use for anything they nick before returning once they sober up (if they remember where it came from along with the collection of traffic cones!).

 andyb211 21 Jul 2020
In reply to muppetfilter:

>  and the geordies are less likely to steal it.

Don't f*cking bank on it! : )

 andyb211 21 Jul 2020
In reply to spenser:

Spence the traffic cones wasn't me!!

The "Wet Floor Signs" however.........

1
 Rick Graham 21 Jul 2020
In reply to GPN:

> Suggest you contact the BMC directly. You’re right that the video shows numerous things that are poor practice (e.g. using a damaged blade).

I have witnessed first hand the human damage that can be caused by a "correctly" used and maintained grinder on construction sites.

Forearm cut through to the bone and almost through the bone.

My first thought was where is all the blood? Fortunately ? the blade cortorised the wound . Nice.

On the video, the metal stopp   as a back up without any apparent shock absorber was  a bit of a wtf moment.

 john arran 21 Jul 2020
In reply to Rick Graham:

> On the video, the metal stopp   as a back up without any apparent shock absorber was  a bit of a wtf moment.

Yes, that seemed particularly odd on what is essentially a climbing instruction video.

Another oddity was the practice of trying to hit an almost flush bolt stub first with the blunt end of a hammer, and then marginally less optimistically with the pointy end whose diameter looked roughly the same as that of the bolt. Surely if you were going to the trouble of taking all that kit up with you you'd also take a nail punch or something similar? And is it even possible for an expansion bolt not to be able to be sunk even a few mm?

 When I'm equipping I make sure the holes are longer than the bolts (as I believe is normal prace nowadays), so if I do need to remove one again I can easily sink the whole bolt without grinding anything, and if I don't have a punch, using a new bolt as a punch can work very well

 Rick Graham 21 Jul 2020
In reply to john arran:

Quite .

> Yes, that seemed particularly odd on what is essentially a climbing instruction video.

> Another oddity was the practice of trying to hit an almost flush bolt stub first with the blunt end of a hammer, and then marginally less optimistically with the pointy end whose diameter looked roughly the same as that of the bolt. Surely if you were going to the trouble of taking all that kit up with you you'd also take a nail punch or something similar? And is it even possible for an expansion bolt not to be able to be sunk even a few mm?

>  When I'm equipping I make sure the holes are longer than the bolts (as I believe is normal prace nowadays), so if I do need to remove one again I can easily sink the whole bolt without grinding anything, and if I don't have a punch, using a new bolt as a punch can work very well

From observation , what normally happens is either the battery or drillers patience runs out and the hole is obviously too short. The inexperienced driller then finds that the through bolt will not come out so just puts the hanger on anyway.

Rare for the hole to be exactly the minimum depth for correct projection, usually a bit spare if the enbedment is right.

Surely this is prominent on the bolters guidance nowadays .

Check the hole depth is adequate and clean it out properly, whether for glue ins or through bolts.

Post edited at 16:20
 Iamgregp 21 Jul 2020
In reply to john arran:

Yeah thought that - when "that bolt's not disappearing for us" my first thought was that this was probably because most of the time he tried to whack it be barely made contact with it! 

 Sean_J 21 Jul 2020
In reply to Iamgregp:

Reminds me of that toy for young children, a toy hammer and a block with different shaped holes and pegs. I think the small child would probably do a better job of it too! This video was painful to watch, they'd probably be best off taking it down and making a new one to address the various issues raised here.

 Enty 21 Jul 2020
In reply to john arran:

> Yes, that seemed particularly odd on what is essentially a climbing instruction video.

> Another oddity was the practice of trying to hit an almost flush bolt stub first with the blunt end of a hammer, and then marginally less optimistically with the pointy end whose diameter looked roughly the same as that of the bolt. Surely if you were going to the trouble of taking all that kit up with you you'd also take a nail punch or something similar? And is it even possible for an expansion bolt not to be able to be sunk even a few mm?

>  When I'm equipping I make sure the holes are longer than the bolts (as I believe is normal prace nowadays), so if I do need to remove one again I can easily sink the whole bolt without grinding anything, and if I don't have a punch, using a new bolt as a punch can work very well


Exactly. God I cringed when he started hitting the stub with the hammer.

E

 jimtitt 21 Jul 2020
In reply to Iamgregp; This video was painful to watch, they'd probably be best off taking it down and making a new one to address the various issues raised here.

At least there will be an impressive array of armchair experts there to show Dan (and us) how to do it properly

1
 Rick Graham 21 Jul 2020
In reply to jimtitt:

> In reply to Iamgregp; This video was painful to watch, they'd probably be best off taking it down and making a new one to address the various issues raised here.

> At least there will be an impressive array of armchair experts there to show Dan (and us) how to do it properly

OK, but on the subject of armchairs, have you tried a belay seat / bosun's chair for long hanging sessions?

In reply to Rick Graham:

Sounds good. Obviously, the faster and more easily the exposed parts of the bolts can be removed the better.

Post edited at 17:13
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 Rick Graham 21 Jul 2020
In reply to John Stainforth:

> Sounds good. Obviously, the faster and more easily the exposed parts of the bolts can be removed the better.

You maybe forgot to add "safer".

 jimtitt 21 Jul 2020
In reply to Rick Graham:

I don't hang around making videos, a couple of minutes is fine in a decent harness, I use a big waĺl one but more or less anything that fits is okay.

 Rick Graham 21 Jul 2020
In reply to jimtitt:

> I don't hang around making videos, a couple of minutes is fine in a decent harness, I use a big waĺl one but more or less anything that fits is okay.

Are you owning up to being the cameraman on this video?

It looks like one you get on an assessment course where you get points for counting bad practice occurances.

Post edited at 17:28
 Sean_J 21 Jul 2020
In reply to jimtitt:

> At least there will be an impressive array of armchair experts there to show Dan (and us) how to do it properly

Well volunteered that man

 Sean_J 21 Jul 2020

#respecttherock

1
 jimtitt 21 Jul 2020
In reply to Rick Graham:

Haven't been to the Lake District since 1968.


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