Been having a tough time lately with ground rods. 4 hours to drive 2 rods last week, then again yesterday. We normally use a 30 lb Bosch demo hammer after first drilling in 2 feet with a rotary hammer. Rented a 60 lb last week, it didn't do any better. Tried a fence post driver, helped on one, bent the other one bad. Tried driving them at an angle, no luck. Any tips? Anyone tried this?: www.condux.com/products/aerial/dddrvr.htm
It costs $250 plus shipping. I am tempted to try it. Sometimes, the demo hammer just goes nowhere but if you can get in some sharp heavy blows it seems to get the rod moving again.
Sixteen feet of hand trenching two feet deep is out of the question without a backhoe or at least a ditch witch.
When you just can't get the thing in more than a few feet... and digging is impractical.. then it's time for a second rod. You also drive it as far as you can, making sure to place it at least six feet from the first, and connect the two with your GEC wire.
#66192 - 05/24/0609:21 PMRe: ground rods and the desert
It's usually about 6 inches of sand followed by a layer of Calichi followed by rock and more Calichi. For those of you who don't know what Calichi is, it's a layer of concrete like deposits formed over time from rainwater mixing with alkali, or lime. It settles several inches below the surface and gets thicker as time passes. It is usually very thick at the drip line of a very old house.
"what if you drilled a hole in the rock and cemented the rod in?"
I usually do drill down 2 feet, but where would I find eight foot rotary hammer bits, let alone a hammer that could drive one?
#66195 - 05/27/0608:51 AMRe: ground rods and the desert
I have used several slide hammers like it, and they do work, however you are going to still have to beat it.... If having problems with a 60# demo/jack hammer, then you have problems it may not solve other than providing another option to do the work. Which when ramping up the tool to the job is not a bad idea.
Either way it sounds rough, a story I know well. Here its a roll of the dice if you're gonna have serpantine bedrock or sand. Sand it will install itself, rock you can beat all day long unless you find a crack. The trick is finding the crack.... And still chance a 1/2' per hour.
On those days when i have to do the pounding, or when nice enough to lend a hand to the lower wage slaves who I have tend this, I often day dream of something like this drilling rig. set up and let rip. http://www.portadrillmini.com/index.php?a=pdmMain
If you know of a freindly fab shop, or own a welder, you may be able to make a lighter duty version to mount a long core drill or extended length hammerdrill to. As for bits, I do know of several siezmic shops that have made thier own for purposes like this, to drive pins and grout. Simular to what this guy makes... http://www.hydratek2000.com/
Sounds like the type of soil your in would be like cementing it in afterwards....
Mark Heller "Well - I oughta....." -Jackie Gleason