I need to drill a hole through 20" of concrete.

[ZenLefty]

Any advice? :shrug:

I've drilled shallow holes through concrete but even with good masonry bits and a good drill it can still take a while to drill an inch or two. Do they sell long drill bits that can bore a hole through that much depth? Will my hand drill work (1.5 horsepower, variable speed) or would it be better to rent something with a little more oompf?

[benito]

1. viagra?

[ZenLefty]

3. The concrete needs to be intact after I'm done.

;-)

[Carrion]

2. Just Wait

It would be much easier if you just wait for the election to take care of Dubya. Rather than trying to drill through something that dense.

[Worst Username Ever]

4. Hammer drill!

Those things are awesome. Finding a carbide drill bit for a conventional drill that is two feet long is going to be difficult.

[mongo]

8. definitely hammer drill time

and buy the best drill bit you can find - and then get at least one more because you will wear the first one out.

I hope that you don't need a hole more than 1/4" in diameter, because that is the most common size for the long bits.

Good luck.

[trotsky]

9. Another successful hammer drill experience here.

I only had to go thru the thickness of a brick (3 inches?) but the hammer drill went thru it like BUTTAH.

I got a 1" long drill bit at Home Depot (I know, Repuke donor, but I needed a 1" hole). If you start small and work your way up it will be fine.

[Ready4Change]

10. I agree on the hammer drill.

I had a choice of renting a heavy duty one, or buying a cheap on. (Same price.) I bought a cheap one, and it was better than a regular drill, but I wish I'd rented the heavy duty one and saved myself some effort.

[ZenLefty]

13. 1/4" would be plenty.

I'd hate to bore anything bigger.

[radwriter0555]

20. YEP, rent a hammer drill from your local hardware store. VERY cheap

and will knock out the job REALLY fast.

I'm a chick, and I know how to use a hammer drill.

[Uben]

5. Rental

Check your local rental stores. Most of them will have a hammer drill, and a lot of them rent the carbide drills as well.

[HysteryDiagnosis]

6. Spend the money, rent a good hammer drill at Home Depot or Lowes

and save yourself some agony. You will need a hammer drill no matter what you do.... I doubt a 3/8 hammer drill will get the job done... but they do sell them for about a hundred dollars these days... you should ask the man behind the counter at the tool rental place just how bad of a drill you will need.

http://shopping.msn.com/marketplace.aspx?pmpType=1&mpId=0&pcId=3061&catId=2555&page=1

This is what I would use.... it has a half inch chuch with plenty of power.

[HysteryDiagnosis]

7. Hey... you're not in prison are ya? n/t.

[Ready4Change]

11. Good question!

:7

[Broadslidin]

19. My Trusty 'ol.........

Just to prove, there's always a solution out there somewhere!

Thanks to a shifty fellow in ordanance that took a case of beer
for it back in '68,
My trusty 'ol 20mm canon taken out of a Navy F-8 Crusader is still
capable of blasting holes through 18 inches
of re-inforced concrete and six inches of steel.

[HysteryDiagnosis]

22. Woah... that's some camera... wink wink..... n/t

[ZenLefty]

12. How much does a hammer drill agitate the concrete?

There are some glass windows nearby - not tempered glass but the antiquated wavy-looking stuff. I've never used a hammer drill before, but the name implies it agitates the material quite a bit. I can always take the windows out, of course.

[Astrochimp]

18. glass near should be no problem, but

a 20" drill bit will be a problem, I had a hard time finding a 18" tow years ago.

Hope you can rent drill and bit.

[radwriter0555]

21. The drill applies the force directly to the bit, and shouldn't affect

anything near by...

[gbwarming]

14. You need a hammer drill

I used to occaisonally drill holes for piping and Hilti anchors through concrete and filled block walls. Never drilled more than 9 or 10 inches tho.

Something like this will hammer and twist a heavy carbide tipped bit through concrete MUCH faster than a conventional masonry bit.

http://www.hilti.com/holcom/modules/prcat/prca_navigation.jsp?OID=-9463

(Edit - I must be the slowest poster on DU. I started my pathetic reply before any others showed, and here I am #20 or so.)

Rent a relly big drill and a decent sized bit. 20" is really long so a 1/4" bit will be very flexy and the small carbide on the end will be easy to rip out. I'm no expert at this but I don't think I'd try a hole that deep with less than a 1/2" bit. Clear the dust out of the hole often because it tends to pack up and jam the bit (less of a problem for a horizontal hole). The windows should be fine.

[skygazer]

16. That's a Hilti drill in that picture

You can probably rent one. It will not cause a lot of vibration and will drill a good clean hole. I used to work construction and drilled many a hole through concrete with one of those babies. Nice tool.

[Rjnerd]

15. You want to rent a SDS system hammer drill

They are a system of hammerdrill and spline drive bit. The bits are available in drilling depths to 22 inches, depending on diameter. They have several levels available: SDS, SDS-PLUS and the SDS-MAX series. The plus and max series will drill bigger holes, and the drill heads have bigger motors. The bits cost more as well.

You may have to call around to find a rental place that deals with contractors, rather than "retail", as the tools are expensive (a SDS-MAX head can cost $1k). For 20" depth, the bit will cost $40 and up, depending on diameter.

I am not a builder, but have played one on TV (Founded the first US team to compete in "Junkyard Wars")

[Ready4Change]

24. A Junk Yard Wars Veteran?

I keep meeting my heros on this forum! Love that show. Makes me want to learn to weld.

[Rjnerd]

25. It is too bad they stopped the US version of it....

They are still making it in the UK, but I doubt we will see those here. If you get the Science channel, they are re-running the season we did. They are supposedly showing us building steam cars, on the thursday after the election. (11/4).

Oh yea, since the US gets 6 extra minutes of commercials, they cut out most of the educational bits, and played up the competitive angle. (In the UK, its pitched as a science teaching show. Trick 8-14 year old kids into watching 15 second lectures, on basic mechanical concepts, by hiding them in a competition)

For those that continue to be curious, lots of details are on the web page below.

[ZenLefty]

27. I caught that show a coupla times.

Thought it was pretty cool. B-)

[Rjnerd]

31. We really enjoyed ourselves,

Worked our butts of tho. Really do the build in one day, and despite a 6am call, we rarely got acutally building before 10am, and it might be midnight before they got done with all the random extra stuff... Woke up the next morning, and my body said "Aren't you old enough to know better?"

Oh yea, all the evil things you have heard about commercial TV producers.... Are understatements.

You can tell who your friends are, they stab you in the chest.

Still, it was such a blast, that if they called tommorow, the response would be "what flight did you book me on?" Where else do you get to cut land rovers in half....

[snippy]

17. Rent the best, most powerful, rotary hammer drill you can find.

Make sure the people at the rental place understand exactly what you want to do. You probably want to rent four or five bits also so that you can change bits as they get dull and in case you break one.

Or you can buy a good rotary hammer drill for a few hundred dollars plus $30 to $60 for a long enough bit.

[Steven_S]

23. Get somebody to do it for you.....

Don't you know a plumber or electrician locally? Can a friend of a friend call someone and just ask them to put a hole where you want it?

It might save you a headache. Or two.

We all (plumbers) have one of these.

[ZenLefty]

26. FINISHED!!

Thanks for the advice, everyone. I ended up getting through it with a 24" x 3/8" drill bit and my trusty ol' Craftsman power drill. I figured I'd try that before I rented other tools and it bore through fine. The drill bit was ruined in the process (ripped the head right off of it at some point) but I still had enough to force it all the way through.

I don't think this concrete is as hard as the stuff they mix nowadays. It was pretty crumbly at the surface, and it took about 15 minutes to bore through the whole thickness (pausing a couple times to sip my beer and cool down).

This project's almost finished. I'll be posting pics soon. Thanks again!! :D

[ThoughtCriminal]

28. What's on the other side?

nt

[ZenLefty]

29. The inside of a fireplace

I needed to run a thermostat wire through some concrete to get to a gas stove. The stove salesman wanted to staple the wire to the outside of the fireplace, along the nice woodwork I had just finished. He's recovering fine, and will be getting out of the hospital any day now.

[Rjnerd]

32. It was firebrick then

Its softer, so the temperature difference doesn't split it. It is easier to get thru.

[realisticphish]

30. black powder

works every time

:hippie: The Incorrigible Democrat

[Johnny 99]

33. Rent something

It will take all day and about four bits to go through 20" of concrete with a hand drill. The ideal thing would be a high-pressure water drill, like they use at rock quarries, but that might be a bit expensive.