Accurate Holes in Concrete? (Slightly Bogus Metal Content)
 

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

did this a month ago in my garage in the concrete block wall.
used a nail to put an indent in the wall then drilled, mounted and reused
the nails in the other holes for a spot for the drills worked fine

"Doug White" wrote in message
...
I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

It helps to turn the hammer function OFF to start the hole. This keeps the
bit from traveling so much. A steel template to guide the bit would also
help. That's a bit of extra work but "it takes what it takes" to get it
done right.

--
Gary Brady
Austin, TX
www.powdercoatoven.4t.com


"Doug White" wrote in message
...
I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White
Starting with a small bit - *and light pressure* should get you the
accuracy you need. Lots of people really lay into the drill when
using a hammer drill - and it's not necessary. If these brackets are
pretty much going to be permanent - you could always use a "bang
stick" and anchor them to the wall - just not easy to remove if you
have to.
Ken.

"Doug White" wrote in message
...
I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

Use a small rotohammer instead of a hammer drill. I had a Milwaukee, and it
was so sweet. There is something about the percussion that is different
than a hammer drill. You don't have to get a big monster that is hard to
hold up there vertical. They are made in smaller sizes. It might help to
drill a small diameter pilot hole, too. A rotohammer is as much better than
a hammer drill as is a hammer drill is to a regular drill.

Steve

"Doug White" wrote in message
...
I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

PS: I would use sleeve anchors rather than the plastic thinguses. Drill
your holes deep enough so if you want to abandon the bracket, you can pound
them in and put some concrete patch in the hole.

Steve

Steve

On Thu, 26 Aug 2004 00:32:21 GMT, (Doug White)
wrote:

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

Use a 3/16 drill as a pilot bit. Then go to full sized.

And use metal expanding anchors. The plastic ones will pull out over
time. Often, in a very short time.

Gunner

"In my humble opinion, the petty carping levied against Bush by
the Democrats proves again, it is better to have your eye plucked
out by an eagle than to be nibbled to death by ducks." - Norman
Liebmann

In article ,
(Doug White) wrote:

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

An awkward pain every time I piddle with this stuff too... same deal
getting clean holes in plaster, stucco tile and brick too.

Miserable materials to work with in my book...

Erik

On Thu, 26 Aug 2004 00:32:21 GMT, (Doug White)
wrote:

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

*Please* tell me you are going to hang the ladder using the metal
hooks and plastic expansion anchors for storage, and not for
structural support while climbing the ladder...

(For climbing support, you need something seriously beefy and
reasonably bombproof like 1/2" expansion bolts or sleeve anchors of
some sort. 1/4" plastic sleeves and #10x1" screws won't cut it.)

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

1/8" carbide pilot bit carefully drilled in to start the hole as
close to the desired center as you can get it, and then a single pass
to your finished hole size. No matter WHAT you do the bit will want
to wander with the aggregate - and it's really going to wander badly
if they used quartz gravel that's harder than heck, so plan on making
one or two holes in the bracket a bit oversized or oval to
accommodate. Or punch a new hole if it moved a mile.

If you are ever making a big roof access ladder or other big steel
structure, don't weld the mounting tabs permanently until after all
the anchor holes for the mounting are drilled - if the hole wants to
wander while drilling you don't fight it, you simply modify the bolt
tab location to match where the anchor ended up...

"Don't raise the drawbridge, Lower the river." ;-)

-- Bruce --
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

My trick with stuff like this is to just drill big and fill the hole with
epoxy to fix the oversized hole and get the fitting where I really want it
to be.
The cheap and dirty is to drill the holes in the part to be mounted later.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!

Doug White wrote:

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

I made a center punch by welding a blob of #6 Stellite ont the end of a
piece of rebar and machining (carbite cutter) an appropriately shaped
point. I've center punched quite a number of starters in concrete with
this. For just three holes, a piece of drill rod hardened and tempered
should do.

Those plastic thingies are junk. Epoxy a piece of threaded rod into
slightly oversize holes (e.g. 9/16" hole for 1/2" threaded rod). This
is far stronger (and cheaper) than expansion fittings.

Ted

Keywords:
In article , wrote:
On Thu, 26 Aug 2004 00:32:21 GMT, (Doug White)
wrote:

I am going to hang a METAL extension ladder using some METAL hooks. Now
that I have established some serious metal content, I need to drill the
mounting holes in the concrete garage wall. The hooks have 3 holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has demonstrated
very poor success at getting holes where I want them. The drill wanders
& bounces off pieces of agragate in the concrete, and I end up with holes
that won't match up with the holes in the bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a little.

It seems to me that the absolute error gets worse with bigger drills, so
I can try starting small and then boring out the hole with a bigger bit.
Another option is to drill the first hole, and then use the hooks as a
jig to ensure that the subsequent holes line up. I was thinking about
using a small bit with a sleeve that fits in the holes in the metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White

Use a 3/16 drill as a pilot bit. Then go to full sized.

And use metal expanding anchors. The plastic ones will pull out over
time. Often, in a very short time.

A couple folks have mentioned using metal anchors. I'm familiar with the
lead expansion anchors, and Rawl plugs (?), which will take a bolt, but
also require a specific depth hole. I also have used concrete screws,
but because my holes usually end up oversized, they never seem to hold
very well.

The weight of the ladder will mostly be perpendicular to the fasteners,
so as long as they don't vibrate loose, there isn't a lot of force being
applied that would pull them out.

Doug White

If it really really concrete, use Powers brand Wedge Bolts:

http://www.powers.com/product_07246.html

These require a special high tolerance drill bit for the lead hole
and suggest an impact gun for installation. Excellent anchor.

Pull out values he
http://www.powers.com/pdfs/approvals...-Bolt-2001.pdf

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"Doug White" wrote in message
...
I am going to hang a METAL extension ladder using some METAL
hooks. Now
that I have established some serious metal content, I need to
drill the
mounting holes in the concrete garage wall. The hooks have 3
holes, and
I'm going to use plastic expansion anchors for the screws.

I have a nice Bosch hammer drill, but my past experience has
demonstrated
very poor success at getting holes where I want them. The drill
wanders
& bounces off pieces of agragate in the concrete, and I end up
with holes
that won't match up with the holes in the
bracket/fixture/whatever. I've
tried using a star drill as a centerpunch, but that only helps a
little.

It seems to me that the absolute error gets worse with bigger
drills, so
I can try starting small and then boring out the hole with a
bigger bit.
Another option is to drill the first hole, and then use the
hooks as a
jig to ensure that the subsequent holes line up. I was thinking
about
using a small bit with a sleeve that fits in the holes in the
metal hooks
to prevent the drill bit from chewing things up.

Any suggestions or tips from the experts out there?

Thanks!

Doug White