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I have a few drilling jobs coming up, so I’m thinking it might be time to invest in something big. The jobs include four holes for 1 1/2″ PVC electrical conduit thru a concrete stemwall, a couple hundred half inch diameter holes thru 4×6 wood girders to install some Simpson “T”‘s, and maybe even loosening up some very hard ground in the crawlspace so I can dig for a new footing. Any suggestions, or am I trying to do to wide a variety of things with one tool?
— J.S.
Replies
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Hammer drills suck!
Rent a big rotohammer for the four holes........
Buy a top quality, min. 7 amp, 1/2' drill with a self-feed ships auger for the wood holes.
Hire a laborer to loosen up the very hard ground in the crawlspace.
*JohnI have a Milwaukee spline drive rotary hammer drill. I can drill holes from 1/8" to 1/2" sds bits with a spline adapt. 1/2" to 1-1/2" with the spline bits And larger holes up to 6" with percussion coring bits. Actually just drilled nine 2-1/2" holes today thru 8" concrete walls hit 4 pieces of rebar in 3 of the holes, the coring bits slow down when you hit rebar but keep on going thru and the teeth still look like new. You can also switch the drill to hammer only and use it as a light duty jack hammer. Have had my drill for about 4 years now and have not had a problem yet. My van is in town but I will check the model number tomorrow and let you know if you are interested.
*Hilti model 75 It's a beaut. You can even buy an adaptor for a 1/2" chuck, but it'd be a mess trying to drill through wood while hammering I reckon. Never bought the adapter.
*Thanks, Kevin -- That sounds like the right setup for what I need.-- J.S.
*Bosch SDS bulldog. Runs a little over $200 but worth it.Cuts through masonry like butter.MD
*Ditto what Mad Dog said. I've drilled through concrete chock full of blue stone with out a problem. and the hammer only with a chisel will knock the snot out of just about anything you can put in front of.
*Kevin, How much do those core drill bits cost?All, I've been using the Bulldog for the past couple of weeks. It drills thru concrete like a wood drill thru wood. The Hilti TE-5 is comparable but doesn't have the hammer-only feature which the Bulldog does have. I've tried it once and it is useful - like a small chipping hammer.xJohn, As for working in a crawlspace, I would reccomend a small, more manueverable tool, rather than a big spline drive. The big units are fine - perhaps - for open area projects - such as breaking up sidewalks - where their weight can be an advantage. -Peter
Seems to me that everything but the 1-1/2" holes in the concrete and maybe even that if your willing to invest time could be handled by a good 1/2" hammer drill. One with a good side handle and possibly a spade handle will help with the augers.
I think I would rent a drill setup with a 1-3/4" diamond core drill. If you have gone a long time without needing a drill that big it may be some time until you need it again. If you don't have experience with core drills it might be better to put the abuse on a rental drill while your learning. Around here the drill goes for around $40 a day and they charge you for the amount worn off the core drill. Better to get a more adaptable and handy model.
Depending on the age and type of concrete involved you may find a hammer drill will work by drilling a series of small holes around the perimeter of the hole and taking out he center with a chisel and hammer. If the concrete is old 6000 psi you need the big guns but most residential concrete, especially if still green, can be "drilled" with a chisel and hammer.
The only hammer drill thaaat has impressed me for durability and strength was a 1/2" Milwaukee Holeshooter hammerdrill. We ran it for hours on end. In dirt and crud and sometimes until it smoked and the bits melted and after a cool down it was up for more. Perhaps it was a fluke but it did outlast 3 lesser drills.
Ditto the Bullgod. The chipper makes it more versitile. I used to use a buddies all the time. My hammer drill just dies.....so I'm doing searches right now.
Tool Crib has a Milwaulkee 5371-8 recon for $140. Doesn't have the chipping. can't tell from the description if it's 1/2 or 3/8th. The mag lists the 5371-6 as 1/2". Not sure what the -8 means.
But.....I'll probably just wait till the last minute...when I absolutely ned it...and get the Bosch Bulldog. As I type this.....I thinking,,,what's the extra $60 gonna hurt in the long run? TC had the BullDog recon for $199.
Might just be making a call to them tomorrow! Jeff * Jeff J. Buck/ Buck Construction/ Pittsburgh, PA *
2nd Generation Buck Const, 3rd generation Craftsman
I went with the Bosch 11236, got it with 1 1/2" and 3/4" chisels, and 1/2", 3/4", and 1" bits. It's the biggest they make in regular SDS.
So far I've used the chisels to start digging the trench for my footing, and take out part of the bottom of one of the old poured in place piers. The wide chisel worked in the hard ground about like the narrow one in concrete, and both got the job done. I'll probably get the 1/2" chuck adapter for the wood work, and a 2" core bit to make holes for the 1 1/2" conduit. I schlepped a dozen five gallon buckets of dirt out of the crawl space on Saturday, and I'm still feeling it.
Thanks --
-- J.S.
I bought a Hilti TE-76 ATC on ebay last year for $437.00 (that included the shipping). With the bits that came with it, the whole setup was over $2000.00 from Hilti. I purchase various bits as I need them, and have found that Fastenal carries lines of bits as good as the Hilti, but way cheaper. It works so well, that I look for big concrete to drill holes through. The ATC feature has saved me from being wiped off a ladder more than once, too. I know it's a risk, (ebay) but I'm thrilled. Where do you live, maybe I'll loan it out. All my subs borrow it all the time, so you may as well. ;-)
Nate
My now seemingly ancient B&D Macho 5 is still putting out the work. I have a hammer drill which is fine for 5/16 holes and such. But the real work is done by the roto-hammer, don't even consider gettng one that won't hammer only. Drop 4 or 5 bills on it if you half to and you can justify a return on your investment. You'll spend as much on bits before you know it. Then you'll have a tool that can do concrete. The Macho 5 is spline drive and i have an SDS and taper adapter for it.
Watch the overheating during prolonged use. Too hot to touch? Too hot to drill.
joe d
Edited 4/6/2002 11:43:45 AM ET by joe d
Here's one that we're looking at from Hilti. Looks like what your looking for. !00% faster than the old type.
Check out the speed of this sucker.
http://www.hilti.ca/holca/modules/prcat/prca_navigation.jsp?OID=-27686&lang=L1
Gabe
I personally like my Milwaukee hammer drill (which gets used 99% of the time as just a drill); but, I totally agree with your suggestion to rent a big unit for a day to bore the 1.5" holes..
Phill Giles
The Unionville Woodwright
Unionville, Ontario