I need to drill a large number of holes in my poured concrete garage
walls to put up some adjustable metal shelf "standards" (rails). The
rails are a u-chennel with slots for the actual shelf brackets, and have
5 countersunk holes spaced along them. I made a drill guide that ensures
that once the ends are in place, the holes for the screw anchors will be
located accurately. I have a 1/2" Bosch hammer drill to drill the holes,
with the appropriate carbide tip drills.
This all works OK, but on a couple of the rails, the ends drilled OK, but
I'm hitting aggragate or something very hard on the inboard holes. It
takes forever (~5 minutes of steady drilling for 1/16" of progress) to
make a hole. My hands are getting numb from the constant pounding.
Somewhere I have some anti-vibration gloves for my old lawnmower, and I
really need to find them.
What I'm wondeirng is what's the most efficient way to use a hammer
drill. Is it best to let it chip away slowly at things & just be
patient, or will really leaning on it help? There are a couple of
"operating points" for the thing. Too little pressure, and it doesn't
hammer at all. A little more pressure, and it start buzzing, but it
isn't recoiling too badly. I could drill comfortably at that level for
a long time. If you lean on it a bit harder when it's hit something
hard, every time it hammers, it hammers on my hand as much (if not more)
than on the hole. Aside from the pounding on my hands, I don't know if
leaning on the thing is going to destroy my drills prematurely. When I'm
drilling the top end holes without a guide, I know that if I use too much
pressure the drill tends to wander more, but with the guide, that's not
I've got 4 tough holes in partial levels of depth, and another 5 to
start. The good news is that I've got 8 holes finished. Any suggestions
would be really appreciated.
16 years ago