Drilling Cement

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I am in the process of installing a handrail down to my basement. I need to attach two of the rail mounts to a cement wall. I spent a few hours trying to drill into the cement--- very slow. I am using a 7/16th drill bit from TrueValue-- it is new and I haven't turned the tip "blue." I got one set of holes done (I need to go in about 1 1/2", but it took forever. Are there better drill bits out there that might speed the job? I have a conventional corded drill, not a hammer drill.
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If the masonry drill bit is ok, the concrete normal (poured concrete foundation wall, 40 years old), and the drill spinning correctly---- could the presence of stones (aggregate) in the cement be a problem? Can a masonry drill deal with stones? Thanks for your help.

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I have never had any success with masonry bits in a standard drill (and I have tried the expensive bits). As soon as the bit hits a piece of aggregate nothing happens except that the bit is destroyed. Rent, buy, or borrow a hammer drill instead.
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You can mannually peck with a conventional drill. Just tap it in and out of the hole. It sucks compared to a real hammer drill, but it's better than just using the regular drill if that's all you got.
But get a hammer drill: they're not that expensive and they work much much better.
John
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Ask me about joining the NRA.
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wrote:

Why dont you get one of those tools that uses a 22cal shell to shoot a fastner. They shoot nails and (I believe) a nail sort of thing with a threaded end to put a nut on, like a stud (correct me if I am wrong, I have only shot nails in the past). These things do the job. I have fired them thru all sorts of stuff.
You could probably fasten tbe railing with JB Weld too, if you have a way to hold the rail in place till it dries. JB Weld holds on anything except those exposed to very hi temps like an enhaust manifold.
Of course a redneck would use duct tape :)
Mark
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Yes I tried all the modern technology, star drills, carbide drills, hardened drills pilot holes, and altogether $20+ worth of crap and no, you cannot drill treough concrete with aggregrate. think of it as a sunk cost. start fresh. the .22 gun works great.
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masonry bit and a hammer drill.
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Alan wrote:

When drilling concrete without a hammer drill, I find a star drill and hammer work better than any type of bit in a regular drill. The ancient method works pretty damn well!
I wonder if anyone having problems with a star drill was like the guy I saw. He put the star drill into his electric drill! The damn thing got hot and lost it's temper! I wonder why? ;-)
--
Tony

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puttster wrote: <snip>

Dave ;-)
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puttster wrote:

This is good to know...you should publish your findings immediately. The concrete industry simply *must* stop putting aggregate in their concrete mix, nevermind that it is a defining element of "concrete". And of course all the fools that have been drilling holes in concrete must stop doing so!
(wonder if he hit a piece of rebar...)
-- dadiOH ____________________________
dadiOH's dandies v3.05... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at http://mysite.verizon.net/xico
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Pelorus wrote:

This TrueValue drill bit -- it is a masonry bit?
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Mike "Rocket J Squirrel" Elliott
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Pelorus wrote:

You should be able to drill it faster than that by hand with a "star drill" and a small sledge hammer.
It sounds like you are using a metal-cutting bit instead of a masonary bit.
Bob
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I use a regular variable speed drill on older concrete and standard masonry bits work - slow on the rpm's, not bad for 3/16 & 1/4. Too fast just heats/blues/polishes the edges of the cutters and if you don't keep it straight it rounds the tips all that much faster. Masonry `Carbide Tipped Bit` is designed to hammer & chip a hole, not really cut like a regular twist bit.
Diamond tipped bits drill quick & work easily,,, hammer drill will bust em quik too .
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Pelorus wrote:

Don't worry too much about bit speed, Just brace yourself and put as much pressure as you can on the back of the drill motor. Try to keep the motor just above bogging down with forward pressure. You can also try drilling a pilot hole first maybe a 3/16 Dave
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wrote:

conventional drill. Buy or rent a good quality hammer drill and have the job done in no time.
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I appreciate all the input. Sounds like I need to fined a hammer drill with an appropriate masonry drill bit (yes I was using a masonry bit before). Typical "simple" project evolves into weekend project.
Thanks to all.

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wrote:

I should have said this too. I tend to drill a smaller hole first, then enlarge it. I'd use a 1/4" first, go to a 3/8" and finally the 7/16". Yes, a hammer drill would get the job done a lot faster. If you forsee doing this again, you might be able to buy a hammer drill for twice what it costs to rent, but then it's yours. Just dont buy a real cheapie. I had a cheap Skil and it didn't do shit. THe "hammer effect" was more of a vibration, and was near useless. I completed the job with my extra heavy duty Milwaukee brand Industrial drill (non hammer drill), and it worked like a dream. Hammer drills require a special bit too. They are usually black in color.
Mark
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Buy a Tapcon Set , use Tapcon, Bit is included, 5-15$. Tapcon may or may not drill better , if it doesnt , rent a hammer drill.
Tapcon is best.
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Only a couple of things I can suggest:
Get a hammer drill, or rent one.
Make sure you don't keep spinning the drill when you feel it stop going in. This will "smoke" the bit, turning it blue. That is a sign of overheating. Keep the rpms up, but not high when you feel it stop penetrating. You can also spray some water into the hole.
Get a piece of cold rolled rod, or some steel that is very hard, but smaller diameter than the hole. Sharpen it to a chisel point. When you feel the bit hit something hard and stop penetrating, stop drilling. Put the smaller rod in the hole, and hit it lightly with a hammer. This will help fracture the piece of aggregate you have hit. If you don't have any cold rolled, stainless, or an old center punch, sacrifice an old screwdriver. Cut off the handle, as it will split. Just keep the point sharp.
A rotohammer will drill each hole in about ten seconds. A hammer drill will do it, but not as fast. A regular drill will do it, but you will probably burn up bits. A powder charge will also do it, but may fracture some concrete.
If you anticipate doing any more of this kind of project, go get a hammer drill. I have a Makita and a Metabo. They are okay, but I prefer a Milwaukee rotohammer for serious drilling of holes larger than 3/8". Any hammer drill will be better than a regular drill.
HTH - try the punch thing before buying a drill.
STeve
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