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Discussion Starter · #1 · (Edited)
I had a thread a while back (Drilling Advice) and most suggested I rent a wet core drill and bit because I'm drilling through a poured concrete wall that has styrofoam and stucco on the outside and drywall on the inside.

Anyway, I rented a Cardi wet core drill with a 2-1/2" core bit. As I said before, I've never used a core drill. Seems simple enough but I have a few concerns.

First, there is no pilot bit with this drill/bit. I suppose you would start slow and at a slight angle until it gets started, but not sure.

Then, with the outside being stucco with a wire mesh/lathe behind it, would I need to drill the stucco and styrofoam with a hole saw first? Or would the core bit be ok to use for it all.

My plan is to drill a pilot hole from the inside, then drill the core from the outside.

Any tips or advice on how to properly do this?
 

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Ive only used a core drill that bolts down.

Besides, if you can use it, how are you going to keep water out from behind stucco?
 

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I had to look up that drill.


I didn't know they make a hand held drill.

How deep is the concrete?
 

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I had a thread a while back (Drilling Advice) and most suggested I rent a wet core drill and bit because I'm drilling through a poured concrete wall that has styrofoam and stucco on the outside and drywall on the inside.

Anyway, I rented a Cardi wet core drill with a 2-1/2" core bit. As I said before, I've never used a core drill. Seems simple enough but I have a few concerns.

First, there is no pilot bit with this drill/bit. I suppose you would start slow and at a slight angle until it gets started, but not sure.

Then, with the outside being stucco with a wire mesh/lathe behind it, would I need to drill the stucco and styrofoam with a hole saw first? Or would the core bit be ok to use for it all.

My plan is to drill a pilot hole from the inside, then drill the core from the outside.

Any tips or advice on how to properly do this?
I am not a concrete guy,but if you secure your drill horizontally to the wall, just drill.
 

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I had a thread a while back (Drilling Advice) and most suggested I rent a wet core drill and bit because I'm drilling through a poured concrete wall that has styrofoam and stucco on the outside and drywall on the inside.

Anyway, I rented a Cardi wet core drill with a 2-1/2" core bit. As I said before, I've never used a core drill. Seems simple enough but I have a few concerns.

First, there is no pilot bit with this drill/bit. I suppose you would start slow and at a slight angle until it gets started, but not sure.

Then, with the outside being stucco with a wire mesh/lathe behind it, would I need to drill the stucco and styrofoam with a hole saw first? Or would the core bit be ok to use for it all.

My plan is to drill a pilot hole from the inside, then drill the core from the outside.

Any tips or advice on how to properly do this?
My hand held core bit doesn't have a pilot either. I just hold it at an angle to get a groove going then turn. I don't think the bit will "see" the wire mesh. I drill with a dry bit in my cordless, up to 2 in pipe.
 

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The last time we cored we used a bolt down, went through crete, steel rods and anything else ....~CS~
 

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I use a 1&1/2" Bosch rotohammer with a 3&1/2" piloted,impact core bit, free hand. The reason I use that size is because they are so expensive. But a 2&1/2" bit should be "Duck Soup"!
 

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Like Backstay said, I'd start it on an angle till you get a decent groove. Then take it nice and slow till you get through the mesh, then have at it.

Let us know how it went when you're done.:)
 

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Discussion Starter · #9 ·
I had to look up that drill.


I didn't know they make a hand held drill.

How deep is the concrete?
Well its a poured concrete wall. I think it is about 8 -10" according to the HO.

Or did you mean how deep is it to the concrete? If so, I would guess an inch or so from the stucco and styrofoam to the concrete.
 

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For hand held core drilling we holesaw a piece of 3/4" plywood just larger than the core bit and anchor the plywood to the wall as a jig until the core bit is started. Core bits that have segmented cutting edges are usually listed for dry cutting also. If you don't want to leave visible marks outside of the actual hole, mount the holesaw plug and place the core bit over it. No extra holes or anchors showing after done.
 

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For hand held core drilling we holesaw a piece of 3/4" plywood just larger than the core bit and anchor the plywood to the wall as a jig until the core bit is started. Core bits that have segmented cutting edges are usually listed for dry cutting also.
 

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I've used handheld core drills and I always use an insert that slides Into the core bit just to get it started. Its a shaft with circular rubber 'washer' (same size as Inside diam. of bit). The shaft has a spikey sharp point on it just enough to get the ho!e started, then you remove it. Works perfectly. Or just find your flattest spot slowly get it started and once its 1/8 or so deep you're golden
 

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You can do 10 inches by hand but it will be tough to get it started if your not used to doing it that way. And im not sure what gonna happen when you hit the Styrofoam from the backside. I almost feel like the little teeth on the core bit will rip a big chunk out of the wall
I would almost be inclined to start on the outside. Holesaw the Styrofoam and thin layer of stucco then do your hole. If its a newly poured foundation and your using a new bit it should go through it in about 10 minutes even by hand.
I have quite a bit of experience with the hilti dd 130. Probably drilled 100 holes with it free hand, bolted down and with vac attachment. If your going to do it free hand just hold it straight and level and you should be ok. And no they dont have pilot bits so use two guys to get it started. One guy wearing gloves holding the bit in place and the other operating the drill. Once you get a groove cut you can go nuts..
 

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Set a couple of blue screws as a basket to set your drill bit on, and you can go in square. The bit will cut styrofoam pretty cleanly and I would trust it to cut stucco as well.
 

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If that thing does not have a clutch, you could go for a ride.
I've never free hand cored. I would think you need to hold it perfectly level as the bit would bind if you got deep into the concrete and moved the angle slightly. That wouldn't be fun.
 

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NacBooster29 said:
If that thing does not have a clutch, you could go for a ride. I've never free hand cored. I would think you need to hold it perfectly level as the bit would bind if you got deep into the concrete and moved the angle slightly. That wouldn't be fun.
When i first started out my jman was core drilling and didnt realize it had a trigger lock. Somehow the cod had him wrapped up and was about to throw him off the ladder but i saved the day by pulling the plug
 

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For hand held core drilling we holesaw a piece of 3/4" plywood just larger than the core bit and anchor the plywood to the wall as a jig until the core bit is started. Core bits that have segmented cutting edges are usually listed for dry cutting also.
+1

We have done the same. I've used a piece of plywood large enough to anchor somewhere on the structure with a couple of screws. Once the plywood is secure, hand feeding is the core bit easy. Use a small square to get the hole started plumb.
 

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If you are low enough to the ground you can cut a v shaped notch out of some 1x. Have a helper hold the wood with one end resting on the ground and the bit resting in the v. Once you get the hole started you can remove the wood.
 

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Just set the drill on Hammer only until it wears a groove in the concrete, then switch to drill/hammer. I've done this plenty of times handheld and it works.
 
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