Hammering a rebar into the ground without bending it

Question

I want to hammer a rebar into semi-hard ground (about 2 feet in). What options do I have in order to hammer it in straight, without bending it in the process?

EDIT: This is a 3/8″ diameter rebar.

Tools I'm currently thinking of:

1. Sledge Hammer - worried that there are better chances of the rebar bending in the process.
2. Rotary Hammer - haven't used a tool like this before. What are the pros/cons? (other than the higher price, compared to a sledge hammer)

Any other options I'm missing here?

Thanks

Answer 1

Depending on the size, you could see about renting a demolition hammer and a ground rod drive bit.

You might also want to bevel the tip of the rod, so it's not just a blunt end.

Answer 2

Good ideas above... the one my electrician taught me is to soak (with water) the ground you're putting the rod into. It astonished me at how much easier driving rod was.

A little necro-edit, here, since somebody recently viewed this... you can fake yourself a ground rod driver for a rotary hammer for super-cheap. Take an old chipper bit (or any big-shank bit you've got -- the chipper was convenient because it wasn't fluted), cut it off to 5-6" from the end that fits in the rotary hammer, get a black pipe nipple about 6" long with an inside diameter that's just slightly larger than your former chisel bit, wrap the chisel bit with enough masking tape to make the nipple a press fit, then add a bit more tape around the outside to make the nipple stay put.

Answer 3

Assuming you are talking about small-diamter bar, which seems likely as you are concerned about bending it, I would suggest a long (12-18" or so) drill bit and drilling a hole in the ground to get the rebar started straight, before finishing with a hammer. A masonry bit will hold up to such abuse best (and do better if it meets a serious rock), but if you don't care about any other use from it you might be able to use a normal twist-drill bit (ie, something cheap and awful to begin with that you won't mind dulling.)

Answer 4

I have effectively used a 24" long earth auger driven by an ordinary cordless drill to make a pretty good hole for placement of a steel post for a sign.

You might try placing the end of the rebar in the chuck of a good cordless or corded drill and see if you can force it into the ground while running the drill. It could be that you might modify the end of the rebar to make it cut better, e.g., sharpen it or flatten it.