Star drill? - Page 3

Posted by Uncle Monster on October 6, 2007, 8:23 pm

> X-posted to other relevant group.
> Before there were concrete drill bits, or electric drills for that
> matter, small round holes in concrete or rock were made by a round
> chisel type tool that was pounded into the stone with a small sledge
> hammer while turning the tool. It might have been 8" or 10" long. The
> face of this chisel had a star-like pattern, only with 4 points, like a
> plus sign " + ". I believe it was called a star drill.
> A Google search brings up a lot of sports drills (training regimen).
> Anyone know if they still make them, or if so, where to get one on-line?
> I'm trying to drill some 40 - 3/4" holes in concrete and my 1/2" corded
> electric drill with a concrete bit stalls on the stone aggregate in the
> concrete requiring me to stop and try to crack the aggregate with a
> large punch. I figured a star drill would work better.
> --
> Bill
> In Hamptonburgh, NY

Bill, the classic hand held star drills are still available.
Unless you're a masochist, the best thing to do would
be to rent a big SDS hammer drill if you don't own one.
I have a Bosch hammer drill that would make short work
out of 40 holes.

http://hand-tools.hardwarestore.com/25-96-star-drills.aspx

[8~{} Uncle Monster

Posted by Harry K on October 6, 2007, 10:46 pm

Yep, 'star drill' is the correct term.

The hammers used on them even have their own names...wel it is really
the name of how they are used vice the hamer itsself..

'Single Jack' - one operator who both holds the drill and hammers on
it.

'Double Jack" - one person holds the drill and another uses a much
bigger sledge hammer. That is one place where the old joke "when I
nod my head, hit it" comes from.

I even have a 3/4" one. I have tried using it a few times but gave
up. If my piddly littlel 3/8" 'hammer drill' won't cut it, it is off
to the rental to rent a big electric. The speed those things go
through holes is more than worth the rental cost.

Harry K

Posted by Steve Barker LT on October 6, 2007, 10:55 pm

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

s

> X-posted to other relevant group.
> Before there were concrete drill bits, or electric drills for that matter,
> small round holes in concrete or rock were made by a round chisel type
> tool that was pounded into the stone with a small sledge hammer while
> turning the tool. It might have been 8" or 10" long. The face of this
> chisel had a star-like pattern, only with 4 points, like a plus sign " +
> ". I believe it was called a star drill.
> A Google search brings up a lot of sports drills (training regimen).
> Anyone know if they still make them, or if so, where to get one on-line?
> I'm trying to drill some 40 - 3/4" holes in concrete and my 1/2" corded
> electric drill with a concrete bit stalls on the stone aggregate in the
> concrete requiring me to stop and try to crack the aggregate with a large
> punch. I figured a star drill would work better.
> --
> Bill
> In Hamptonburgh, NY
> To email, remove the double zeroes after @

Posted by willshak on October 6, 2007, 11:28 pm

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.

> s
>

>> X-posted to other relevant group.
>> Before there were concrete drill bits, or electric drills for that matter,
>> small round holes in concrete or rock were made by a round chisel type
>> tool that was pounded into the stone with a small sledge hammer while
>> turning the tool. It might have been 8" or 10" long. The face of this
>> chisel had a star-like pattern, only with 4 points, like a plus sign " +
>> ". I believe it was called a star drill.
>> A Google search brings up a lot of sports drills (training regimen).
>> Anyone know if they still make them, or if so, where to get one on-line?
>> I'm trying to drill some 40 - 3/4" holes in concrete and my 1/2" corded
>> electric drill with a concrete bit stalls on the stone aggregate in the
>> concrete requiring me to stop and try to crack the aggregate with a large
>> punch. I figured a star drill would work better.
>> --
>> Bill
>> In Hamptonburgh, NY
>> To email, remove the double zeroes after @
>>

--

Bill
In Hamptonburgh, NY
To email, remove the double zeroes after @

Posted by RicodJour on October 6, 2007, 11:48 pm

> 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

Page 3 of 15 < 1 2 3 > last >>

Similar Threads	Posted
Integral drill rod and tapered drill rod	August 14, 2006, 10:54 pm
Premier Home Builders/USA Five Star Homes LP in Little Elm, TX	May 22, 2007, 1:59 pm
Former Head of 'Star Wars' Program says 9/11 an Inside Job	May 1, 2006, 4:06 am
Re: Ryobi Cordless Drill Charger	May 8, 2007, 1:36 pm
Air leg rock drill and quarryin & mining tools	August 14, 2006, 10:56 pm
cordless drill batteries - Milwaukee recall	October 23, 2007, 12:53 pm
Bosch cordless hammer drill, unbelievably cheap!	November 2, 2008, 10:23 pm
Need a good cheap hand-held drill guide (mostly for 90° drilling)	October 22, 2007, 6:13 pm
5 star Hotel,office Tower,luxurious house Development Land For sale in Istanbul Turkey	October 19, 2007, 9:00 am