I know this has been covered in other threads, I did a search through the archives. I'm looking at Hilti demolition hammers, but would really prefer a combo unit in case I want to core or drill. For the price of these ($1200-$1450) I'd like it to do more than pound ground rods.

The soil around here (swampland, Illinois) is better than Arizona. I can get a ground rod in with a 4 lb. hammer in about 30 minutes when it's tough. I don't know how anyone uses a sledge. I'd probably miss the rod & hit my leg. I may also opt for the cheap pipe with sledge head welded on.

So the question is what model do you have, how is it holding it 8' up with ground rods? If you use it for drilling or coring, what size holes, etc.? Any info would be greatly appreciated.

I've never used these before & its about triple what I usually spend on tools. I want to make sure it will be my new best friend.

Dave

I worked at a place that used a Hilti TE60 or similar (too long ago to remember) with the proper 'bit'. It was great! Pounded a 10 foot rod in a few minutes.

I'm a little embarrassed to say what it's like holding it up on a 10 foot rod. Would it suffice to say that no ladders were involved?

I have a TE76 and use it mostly for ground rods but do blast holes in foundations with it as well. When I install a rod strait down I drill down 1st with my long bit then start the rod by hand then just put the Hilti on it and shoot it in. Only takes a few seconds or a minute at best if it it tough.

I've got a 1-1/2" Milwaukee roto-hammer I use for ground rods. Certainly has made me a bit lazier about driving rods.

Just out of curiousity, has anyone ever used a big cup of water and drove one hydraulically?

I had 2 guys yesterday using a light Hilti Hammer with a ground rod driver.

It took 3 hrs to drive an 8'x 5/8" and a 10' x 3/4". The soil was very hard clay.

Be sure that the driver you get has enough weight & punch to do the job. Holding a heavy hammer up for a few minutes sure beats holding a light one up for a few hours ...S

Can you find out the model number of that light Hilti, electure? I'd really be upset to spend $1,000 0n something to light to do the job.

Dave

Dallas
"Just out of curiousity, has anyone ever used a big cup of water and drove one hydraulically?"

I've never heard of it, if you can explain how i'll try it.

Hi Dave, I use a Dewalt DW541K Rotary Hammer Drill. 3/4" ground rods are no problem for it. It will take a 1 1/2" bit and I have dry cored 4" holes for Wiremold poke thur floor boxes. I also use it as a chipping gun. The company I work for has about 50 large hammer drills. A combination of Dewalt and Bosch. They used to buy Hilti but don't anymore. I believe the reason is price.

Driving one with a cup of water:

I use a 32oz cup full of water. I start the ground rod by simply pushing it as far as I can get it and still withdraw it. Withdraw the rod, fill the hole with water, replace the rod, and shove the rod down HARD, as far as it will go and still pull out partially. Pull up on the rod two feet or so, but not completely out this time. And repeat. Trickle water down the rod to wash off the resistance of the mud on the rod each time you pull the rod back up, enough to wash off the rod mostly, but no more is needed. The water also will run down into the ground along the rod, and as you shove the rod down again, the water provides hydraulic pressure by being compressed in the hole by the rod, and this shoves dirt out if the way.

If you've ever watched an older well drilling rig, they use the same method to drive a casing to some pretty good depths.

Of course, this works best in morain soils, since really sandy soils won't contain the water in the pounded hole long enough to create the pressure needed, and rocky soils will cause the same problems AND the rocks themself block the rod. Clay soils can be worked if you find some sand to help loosen the grip of the wet clay, but it's a job.

Now, there were a couple of inspectors who didn't like us "drilling" with water, but none could ever cite a Code violation. If you wait a while for the ground to drain, you can't pull the rod back out, so the one concern of a "loose ground" seems groundless!

I have tried using my rotary hammer to drive ground rods but it is too slow for me. I use a Bosch demolition hammer which works great. Hilti makes great tools but since it sound like you’re not going to be using this tool that frequently you might want to consider getting both a rotary hammer and 20-30lb demolition hammer from another manufacture for about the same price. I haven’t priced these tools recently but I would guess you could get the demolition hammer for around $800 and a decent rotary hammer for $400. The demolition hammer will work much better for the ground rods, breaking concrete and trenching with a clay spade. The large rotary hammers can do pretty well for all of these things but they are very heavy to use for drilling.

Curt

Like JoeyD, I have a TE76 and haven't had any problems driving in rods to date, it works like a champ. I actually triple check for underground nuisances like water mains, sewer lines, gas lines etc. 'cause that Hilti doesn't care. BTW, Hilti's are expensive but they do sell some bit package deals, which aren't bad so long as you have a use for all the bits in the package.
Andy

Dave,
Sure, I'll try to check on Model # on Monday.

Guys,
Aren't ground rods supposed to be driven into undisturbed soil?? Is all this water-pouring and hole-drilling OK??

Thanks, guys. I really appreciate your input on this.

Dave

Dave,
I welded an old disused 30mm Diameter (Deep type) socket on to the end of a busted SDS (Hilti) bit, I've been drivin' with it ever since.
Just goes to show how versatile a welder can be.

Dave,
Sorry I never read your original post.
I've used the TE-22 and the TE-25 Hilti's and I must say as far as an EC's piece of gear goes, GET ONE!.
I've used then for straight concrete drilling up to 32mm diameter.
Plus with a Core-Bit you can drill a hole up to 100mm diameter.
You very rarely ever see an EC down here in NZ that doesn't carry one of these drills, they are a truly Industrial-rated Hammer Drill.
Just watch the Boy around the smaller sized bits, they are easy to snap!.

Thanks, Mike, I appreciate your reply. I have a smaller rotary hammer for the smaller bits. Now I just have to find a conversion table for mm to inches.

Dave

Is the TE-22 and 25 what you're using to drive ground rods also, Mike???

Dave

Hi, Dave
How about this link for conversion. http://www.taylormade.com.au/billspages/conversion_table.html

Thanks, electricman786. So that's about 1.25" drill and 4" core.

Dave

I've used the water trick too. It works great.

Dave, if you are looking to primarily drive ground rods, have you considered that fence post tool that is in the fencing material isle at Home Depot? It is a hollow cylinder with handels on both sides and a big weight at the top. Slide it up and down to drive it in. I haven't used one for that, I have a Bosch that I drive the last 2' after the water thing gets too tight. But I either saw someone else using it for that or maybe a home improvemnt show and thought, "hey, good idea"

My Bosch is either:
11219 EVS
11233 EVS
11220 EVS
11232 EVS

I don't know which one, I'm going off the manual here in the office.
Then get 1-3/8 X 18" spline drive. Extra length has been useful many times. takes the hub on 3/4 LB and will take a 1" HW. The smaller pipes get a little more silicone.
Then a chisel (longer is better), GR driver (after the second one cracked I just balance it on top. The guide cone cracks pretty easiliy, maybe user negligence letting the tool hang by it). And a 2-1/2 core bit.

I'm a little suspicious of the water trick, JPS1006, but I'll give it a try. As you know, in this area, if it's swampland-black dirt...a few whacks & you're done.

Sometimes, though, it's gravel-pit country & that's when I'm looking for more than a hammer. When it's tough going, I'm using a hammer...I hit the rod 25 times and have to measure it to make sure it's moved. It doesn't happen often, so I'm not sure it's worth the $$$. However, in the past when I've finally bought a tool I wasn't sure I'd use, I find myself using it very often once I have it.

Dave

Dave

Dave
Ist rent electric jack hammer with ground rod driving bit from rental place like home depot. I bet you will love it after using and ask them how much it cost. I use an old milwaukee jack hammer. It makes life easier.

Dave,
Yes,Dave, it is!.
I'd personally use the TE-25 though, it's more rugged than the 22.
I used the 25 at a recent "RF Ground Driving" stint at a local Ham's Shack.
I told the older guys to put the club hammers away.
After I drove a series of Galv rods into the ground, with little or no effort at all,
there was much head scratching amongst the congregation of fellow Hams.
Followed by "Can I borrow that?".

HI
I have not posted here in a long time but I have a TE-60 I bought on ebay for under $100 and I intentionaly bought an older, as in metal body, for the weight. I install ground rods with one hand in my pocket. It is on it's way back from Austrailia on a slow boat where my son and I were on a three month job and in the month we have been back I sure miss it.

Back in June I was involved in a project to ground a 400' communication tower being built. The specs said that there was to be a ground grid, consisting of #2 copper, which was to be placed in a 36" deep trench, in a cross-hatch method. At every 10-15' of conductor, we had to place a 10' X 3/4" rod. Now consider this. The top of the rod was to be 36" deep, also. No problem, Huh?

At 4', we ran into shale rock. Tried the hilti method (both straight and 45 degrees), which did not work. One of my fellow workers said that the line crew for our utility had a rod driver bit which fit on a jack hammer, driven by a large air compressor.

Worked good for the first 5 rods, then started to bog down. I was standing in the trench (36" deep. remember) while my fellow worker was standing on grade. He would hold the jack hammer and control the air, while pushing down. I would reach up to the jack hammer body, and pull down, letting my 240lbs assist in the driving of the rod. this work for about 5 more rods.

Then the unthinkable happened. The bit, which was nothing more than an old jack hammer bit, cut off about 12" in length, with a 3/4" hole driller into it, broke.

Since my fellow worker was running the controls, and bending over somewhat, he let go of the handles to catch his balance. I, on the other hand, was in the trench pulling down on this heavy piece of equipment, could do nothing but turn away from what I was sure was going to be head wacking event.

It fell, but instead of hitting me in my hardhat, it pulled my right arm behind my back, while I was turning away from it.

Needless to say, 90 days and 1 operation for a torn rotator cuff later, I still don't have 100 percent use of my right arm, tho I am doing alot better now. I can comb my hair with my right hand, shave, shake hands, etc...

My advice it to try the Hilti, but be carefull of over extending yourself with it. If you have to go with a jack hammer type of driver, I pity you, and ask you to be extra carefull using it. I thought I was, but in 1 second I found out I was wrong.

Rick Miell

rmiell,
Really sorry to hear about the injury, thats a really heavy item to come down on you like that, hope it heals up soon.

Best of luck,
Mark

Dave I have used the water trick with great success. I feel that it is alot safer than having someone swinging a hammer over another persons head as they steady the ground rod. Just keep the rod wet and moving it in an up/down motion and you will be surprised at how good this works. And it really doesn't take a lot of water.

Free Water vs $1000.00 Hilti


Point me to the water!!!

Good luck

[This message has been edited by Bert66 (edited 11-01-2004).]