Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Thanks!

DeanB

dean wrote:
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Thanks!

DeanB

Certainly is. It's called a core drill. Available in wet versions or dry
versions. The cleanest, most efficient, and easiest drilling is a wet
diamond bit. Problem is, the cost hundreds of dollars, and require
either a special drill that directs water into the center, or a water
swivel attachment for a conventional drill.
Dry core bits work much slower, and cost a lot less.
Do you need a very clean & accurate hole? If not, save your money &
punch it out with a series of 3/8" holes & a chisel.

Yeah. Try larger builder merchants and/or plumbers merchants. They
can be quite expensive, so try to befriend someone who can get
wholesale.

Over in England they range from £20 to £100's, but my father got one
from a "wholesale" buddy for less then £10.

Having said that, if it's just one hole, then i'd be tempted to just do
the pin cushion drilling as you described.

On 14 Nov 2006 13:17:17 -0800, "dean" wrote:

Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Thanks!

DeanB

Drill a series of small holes and then punch the core out. Purchase
a half round ******* file. The file isn't meant for concrete but will
do a nice job in smoothing and accurizing the hole. You may have
to throw the file away when done, but it will work.

hamilton tool beaver falls pa sells surplus diamond core bits fo 25
bucks a inch, a real bargain.....

they sell mail order and are good to deal with

On 14 Nov 2006 13:17:17 -0800, "dean" wrote:

Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?



Why not just punch a cinderblock-sized hole with a 5 pound mallet,
and then stuff mortar in everywhere that's not part of the 4" hole?

dean wrote:
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

1/2" SDS hammer drill and a cold chisel. 4" is nothing.

I've looked at chisel bits for my 1/2 inch Bosch hammer drill and wondered
if they could make a hole that is anywhere close to round. Can the chisel
bit actually be used for making round (or close to round) holes?

Thanks,
Smarty



"Father Haskell" wrote in message
ups.com...

dean wrote:
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

1/2" SDS hammer drill and a cold chisel. 4" is nothing.

Father Haskell wrote:
dean wrote:
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

someone has already pointed out coring bits. if you want a neat hole badly enough, you could look in the yellow pages. there are companies out there that cut and drill concrete. you might even be able to rent a bit.

On Tue, 14 Nov 2006 16:52:42 -0500, wrote:

On 14 Nov 2006 13:17:17 -0800, "dean" wrote:

Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Thanks!

DeanB

Drill a series of small holes and then punch the core out. Purchase
a half round ******* file. The file isn't meant for concrete but will
do a nice job in smoothing and accurizing the hole. You may have
to throw the file away when done, but it will work.

Do they sell card files anymore? I've not noticed one.

Smarty wrote:
I've looked at chisel bits for my 1/2 inch Bosch hammer drill and wondered
if they could make a hole that is anywhere close to round. Can the chisel
bit actually be used for making round (or close to round) holes?

Rough it out maybe 1/2" undersized and clean it up. It's masonry
work, it's going to be rough.

Try he
http://www.dynatech-diamond.com/dyna...p_ID=6&CATID=4



"dean" wrote in message
ups.com...
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Thanks!

DeanB

Thanks for the advice. I did not know how the chisel bits were used and know
I understand. Thanks again!

Smarty

"Father Haskell" wrote in message
oups.com...
Smarty wrote:
I've looked at chisel bits for my 1/2 inch Bosch hammer drill and
wondered
if they could make a hole that is anywhere close to round. Can the chisel
bit actually be used for making round (or close to round) holes?

Rough it out maybe 1/2" undersized and clean it up. It's masonry
work, it's going to be rough.

dean wrote:
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

I've seen a lot of recommendations for various drills, but what about
marking the hole and using a rotary zip saw to cut it? I'm sure there
are masonry bits available for those larger zip saws, considering even
my little Dremel tool has such a thing for small masonry cuts.

According to dean :
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

As others have suggested, renting a core drill, or using a hammer
and appropriate chisel are the simplest way.

I have, however, watched experienced electricians punch 2"
conduit holes in cinderblock with nothing more than a 2
pound hand sledge. Not perfectly circular of course, but
close, and you have to seal it anyway.

I probably shouldn't recommend that tho, unless you have something
to practise on ;-)
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

On Nov 14, 7:02 pm, Goedjn wrote:
On 14 Nov 2006 13:17:17 -0800, "dean" wrote:

Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?Why not just punch a cinderblock-sized hole with a 5 pound mallet,
and then stuff mortar in everywhere that's not part of the 4" hole?

Leave it to the architect to go with a figure/ground study.

R

On Nov 14, 4:17 pm, "dean" wrote:
Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Drilling holes around the circumference is the easy way to do it. You
don't need additional tools and expenditures and it's almost as quick
as a core bit. If you have a 4.5" angle grinder with a diamond blade
you can clean up the hole to make it rounder. It'll make more dust
that you'd believe, but it will do it just fine.

R