Drilling thru Rock and Cement

I need to dig a hole and drill thru rock and possibly cement to lay base materials for an out door kitchen. What are the best cordless tools to drill a 1 inch hole thru rock, up to 18" thick? Yeah, I know; move the kitchen, but space is a factor; this is where the hole needs to go. Any good ideas?? thx

I would rent a hammer drill. You aren't going to have much fun using a cordless drill.

You'd end up recharging the drill probably50 times, and would be unlikely to actually get it done.

You could rent a gasoline powered coring drill, but you'd have to also try to pick up a bunch of extensions, and crack out the plug periodically, since you would be unlikely to find a core bit that deep, or if you did, it would bind and wrap you around the drill motor.

Depending on the type of rock, and how clean you want the hole, a hammer drill can do it as well, but you might end up splitting the rock when it comes through the other side.

hole

Hire a professional hole driller. By the time you assemble the things you need you will have paid more than his charge, and you might spend many times his fee if you damage the core bits. On one job the DIY hole driller burned out a $600.00 bit in a matter of 1" of drilling.

Drilling 18" and drilling through rock (vs concrete) is probably gonna be too much even for a corded hammer drill.

What you need is an SDS Max Rotary Hammer. You can rent a Bosch or Hilti from BORG for about $50/ 4 hrs. This will allow you to either drill deep, clean holes and to even chip out wider areas. I wouldn't use it for chipping more than a sump-sized hole, though.

I used small hammer drills 1/4 inch drill bits to make a 7 inch hole in 8 inch thick concrete. It was a slow and time consuming task to make holes around in a circle and then chip out the middle with a hammer and chisel.

I found that generous use of water helps keep the bit cool.

Next time I plan on renting a larger hammer drill.

Unless I decide to try something as an experiment. Like making a water flush adapter that would flush water down the outside of the bit by drilling a hole in a square tube such that the water is forced down one side of the spiral.

prashster said:

Drilling 18" and drilling through rock (vs concrete) is probably gonna be too much even for a corded hammer drill.

What you need is an SDS Max Rotary Hammer. You can rent a Bosch or Hilti from BORG for about $50/ 4 hrs. This will allow you to either drill deep, clean holes and to even chip out wider areas. I wouldn't use it for chipping more than a sump-sized hole, though.

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this is the easiest and best way to do it. I have useds these to put 1.5" holes 24" deep in concrete before worked great