On Oct 6, 11:28 pm, willshak wrote:
on 10/6/2007 10:55 PM Steve Barker LT said the following:

You need to rent or purchase a good hammer drill. You also may be
encountering rebar.

No rebar. I'm drilling 3/4" diameter holes 2" deep in a poured concrete
sidewalk around my pool. The holes are to attach a mesh winter cover on
my inground pool. The holes are to hold the cover's 40 spring loaded
straps. Previously, I had been using the solid winter cover with water
bags. I just got tired of cleaning the water and debris that accumulated
on top of the cover when I went to open the pool in summer. I looked
enviously at my neighbor's mesh cover all winter and it was clean except
for a couple of twigs laying on top. Then I looked at mine and there was
a foot of dirty, leafy water after the rain and melting snow had pushed
the cover deeper into the clean pool water.

When I first start the drill, I can see the crushed concrete powder
coming out and forming a ridge around the hole. All of a sudden the
powder stops building and I can hear the drill bit kinda bouncing over
something. The bit never stops turning, it just stops cutting.
I wash out the hole and look in. The aggregate filler in this concrete
is small roundish pebbles, about the size of a green pea up to a lima
bean size with colors of yellow, orange, grey, or whitish. I may see
parts of one, or two, or maybe three pebbles intruding in the hole, the
tops of which look sanded from the drill rather than cut. At this time I
take the small sledge and a 12" long steel tapered flat nosed punch with
a 1/4" wide tip and try to crack the pebbles into smaller pieces that
the drill bit can handle. I think that the 3/4" hand tool star drill can
do a better job of cracking the pebbles with fewer blows since the star
drill will completely fill the hole and may crack two or more pebbles
with one blow.

The hammer drill (or better yet, rotary hammer) is one of the more
indispensable tools - there's nothing that works even remotely as
well. Your question is vaguely akin to someone asking which is the
best brand of screwdriver to use as a chisel, 'cepting a screwdriver
is a lot closer to a chisel substitute. Yes, I know they used star
drills for ages, and yes I know you could do it that way, but I'd
borrow or rent one, or buy/sell on eBay to get the proper tool for the
job. You'll find all sorts of projects for it.

R