Core Drill

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Speshulk

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Not sure if this is the right section of the forum, but I'm not seeing anything specifically about tools.

I'm looking into getting a hand held core drill. A local plumber occasionally lends me his Eibenstock when I need it and I leave him a 20 in the box when I return it to his shop, but I need my own. It works great, but I find that it is a bit tough to get holes lined up neatly with the hand held drill since it walks around some when you initially start drilling the hole. I'm wondering if anyone knows of a hand held drill that has a simple wall mount guide attachment.
 
Speshulk said:
.... It works great, but I find that it is a bit tough to get holes lined up neatly with the hand held drill since it walks around some when you initially start drilling the hole. I'm wondering if anyone knows of a hand held drill that has a simple wall mount guide attachment.
Click to expand...
Core drill (or hole saw) some "buttons". For example, hole saw a few holes in some FRP (or other resilient flat stock) and save the "cores", aka "buttons". Now when you go to core drill a hole, layout the center of your hole(s) and screw one or more "buttons" to the center. This will keep your core bit from walking. Save "buttons" for future use. I left size out of the steps but I think you'll figure out on your own how size is relevant... :D
 
If you're using hollow circular dry core bits they come with a pilot bit for starting the hole.

bshnhc8526.jpg
 
Cow said:
Dry core or wet core?
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the one's rob pictured are dry core. i've got a couple,
stick them in the hammer drill, and away you go.
mine are hilti's.

price them sitting down, with a stiff drink.

rebar is the kiss of death for them. i needed a couple holes,
but if you really need holes, a wet drill is really what needs
to happen. they are slow, in my experience.

hilti makes a high speed dry drill, but it's gawdaful expensive.
 
Fulthrotl said:
the one's rob pictured are dry core. i've got a couple,
stick them in the hammer drill, and away you go.
mine are hilti's.

price them sitting down, with a stiff drink.

rebar is the kiss of death for them. i needed a couple holes,
but if you really need holes, a wet drill is really what needs
to happen. they are slow, in my experience.

hilti makes a high speed dry drill, but it's gawdaful expensive.
Click to expand...

At my last job we always subbed out the coring. I think anything over 4-6" was wet.
 
gadfly56 said:
At my last job we always subbed out the coring. I think anything over 4-6" was wet.
Click to expand...

in my experience, anything beyond a single hole or two, i call a guy....
if i wanted to be a core driller for a living, i'd not have bought a wiggie...

one thing i did buy when i had a bunch of layout for coring was this
thing from hilti... it is expensive, but very worth it.

it will lay out thru penetrations up to about 4' thick. you put the transmitter
on one wall, making sure it's square to the path of the conduit, and go
to the other side... you'll see where it comes out within a quarter inch or so,
and how many inches thick it is.

https://www.us.hilti.com/measuring-systems/detection-systems/r3538
 
Smart $ said:
Core drill (or hole saw) some "buttons". For example, hole saw a few holes in some FRP (or other resilient flat stock) and save the "cores", aka "buttons". Now when you go to core drill a hole, layout the center of your hole(s) and screw one or more "buttons" to the center. This will keep your core bit from walking. Save "buttons" for future use. I left size out of the steps but I think you'll figure out on your own how size is relevant... :D
Click to expand...


Great idea, but I think I'll try the reverse. I have about a dozen holes to drill on 2 different buildings. Instead of keeping the cores, I'm thinking I'll just pre drill my pattern into a piece of plywood and attach it to the wall to use as a guide. Thanks!
 
Speshulk said:
Great idea, but I think I'll try the reverse. I have about a dozen holes to drill on 2 different buildings. Instead of keeping the cores, I'm thinking I'll just pre drill my pattern into a piece of plywood and attach it to the wall to use as a guide. Thanks!
Click to expand...
I've used this method too and it works well also.

The reason I brought up the buttons method first is because you can attach the guide to what is going to be removed and leave no trace. Attaching "button holes" usually leaves a trace.
 
Speshulk said:
Not sure if this is the right section of the forum, but I'm not seeing anything specifically about tools.

I'm looking into getting a hand held core drill. A local plumber occasionally lends me his Eibenstock when I need it and I leave him a 20 in the box when I return it to his shop, but I need my own. It works great, but I find that it is a bit tough to get holes lined up neatly with the hand held drill since it walks around some when you initially start drilling the hole. I'm wondering if anyone knows of a hand held drill that has a simple wall mount guide attachment.
Click to expand...

We use a long hammer drill bit that is the same size or a little smaller than the pilot bit on the core hole drill and drill it all the way through the wall before we use the core drill. If you take the time to set a torpedo level and a framing square (on the bit), the pilot hole will be level and square. Once the pilot hole is established, the core drill pilot bit just follows the pilot hole all the way through. When you get close to the other side of the wall stop and start drilling from the other side of the wall. This will will eliminate any blowout of the concrete or block.
 
Core Bore makes a nice hand held unit, its wet drilling though. They are a much cleaner hole than the dry hammer bits
 
Fulthrotl said:
rebar is the kiss of death for them. i needed a couple holes,
but if you really need holes, a wet drill is really what needs
to happen. .
Click to expand...

I had to drill about 10 holes through a 24" deck a few years ago .... rebar every 4". Dear god the hole saws we went through...... drilled it wet though. Took two days.

Built a drive-thru for McD's on top of a parking deck that was street level at the front and went underground at the back. And then all conduit on bottom of the desk and penetrated back up into the store.

College town Tallahassee at the corner of FSU....... st Patrick's day..... parking garage full of piss and puke. Good times.


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brantmacga said:
I had to drill about 10 holes through a 24" deck a few years ago .... rebar every 4". Dear god the hole saws we went through...... drilled it wet though. Took two days.

Built a drive-thru for McD's on top of a parking deck that was street level at the front and went underground at the back. And then all conduit on bottom of the desk and penetrated back up into the store.

College town Tallahassee at the corner of FSU....... st Patrick's day..... parking garage full of piss and puke. Good times.


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Click to expand...

<shudders> Blah, a lot of the parking structures out here are pre/post tension slabbed and have to be X-ray'd before drilling, whole area is cleared, "ain't cheap" :happysad:
 
ShockedMonkey said:
<shudders> Blah, a lot of the parking structures out here are pre/post tension slabbed and have to be X-ray'd before drilling, whole area is cleared, "ain't cheap" :happysad:
Click to expand...

try plan "b".... breaking a post tension cable on the fifth floor of a hotel across
from john wayne airport. it shot out the side of the building, and poked a hole
in the glass side of the building next to it. imagine a .30-'06 going off in a small
room next to you. that's what it sounds like. no doubt that something important
had happened. and the curves in the cable blow out concrete a few inches wide,
and 4' long.

x rays are better.... this one, they cut the cable off flush, and then cut the
loops that blew out of the deck.. there were arches of cable bulging out everywhere.

i apologized, and said i was sorry....
 
Fulthrotl said:
try plan "b".... breaking a post tension cable on the fifth floor of a hotel across
from john wayne airport. it shot out the side of the building, and poked a hole
in the glass side of the building next to it. imagine a .30-'06 going off in a small
room next to you. that's what it sounds like. no doubt that something important
had happened. and the curves in the cable blow out concrete a few inches wide,
and 4' long.

x rays are better.... this one, they cut the cable off flush, and then cut the
loops that blew out of the deck.. there were arches of cable bulging out everywhere.

i apologized, and said i was sorry....
Click to expand...

[✔️] Rekt
[ ] Not Rekt


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I just did 12 holes in a building, all 2", rebar in every hole. I did it with a core bor and diamond bit. It took almost 3 hours to do them all. It's much better than the hammer drill and so much quieter, less abuse on the body too.
 
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