April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

| Are the surfaces of cement harder? Or does the tip
| of the bit heat up and work better when it's hot?
|

No. Better to cool it with some water. You may have
hit a pebble. Concrete can vary a great deal in terms
of hardness. Some is soft. Some is nearly impossible
to get through.

On Tuesday, April 19, 2016 at 7:38:55 PM UTC-5, Stormin Mormon wrote:
April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?


....even if you meant to say 1/32"? They don't plastic anchors that small...3/32" possibly. I've bent 1/8" in masonry...can't imagine putting the necessary pressure with a hammer drill on "1/36 in"! Never noticed any difference in hardness.

On Tue, 19 Apr 2016 20:38:50 -0400, Stormin Mormon wrote:

April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?

I have no idea about the relative hardness of specific areas of concrete, but what size bit were you really using?

On Tuesday, April 19, 2016 at 7:38:55 PM UTC-5, Stormin Mormon wrote:
April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?
--
.
I believe concrete cures from the surface in. I recall reading that the concrete at Hoover Dam is still curing. It seems to me that the surface of concrete would be the hardest. I've noticed that it's more difficult to drill holes in old concrete than new concrete. ^_^

[8~{} Uncle Hard Monster

On Tue, 19 Apr 2016 21:12:11 -0400, "Mayayana"
wrote:

| Are the surfaces of cement harder? Or does the tip
| of the bit heat up and work better when it's hot?
|

No. Better to cool it with some water. You may have
hit a pebble. Concrete can vary a great deal in terms
of hardness. Some is soft. Some is nearly impossible
to get through.


Depends how much Viagra was added to the cement. More viagra makes it
get HARDER!

Seriously, the very surface often has more portland cement because of
troweling. So, it may be a little harder. Also, the rock may be quite a
bit softer, but that depends on where the quarry is located. Your bit is
going thru stones, sand, and the actual cement. So there will be a lot
of variances as you drill thru it. Also, some concrete blends are harder
than others. It depends on how much portland cement is added, and in the
case of precast concrete, it's harder yet, based on other additives.
Dont forget, you could drill thru rebar and wire mesh too.

You DO NOT want your bits getting hot. Run a slow trickle of water as
you drill.

On Tue, 19 Apr 2016 18:12:57 -0700 (PDT), bob_villain
wrote:

Never noticed any difference in hardness.

I bet your wife does ...........

On Tuesday, April 19, 2016 at 9:22:30 PM UTC-4, Uncle Monster wrote:
On Tuesday, April 19, 2016 at 7:38:55 PM UTC-5, Stormin Mormon wrote:
April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?
--
.
I believe concrete cures from the surface in. I recall reading that the concrete at Hoover Dam is still curing. It seems to me that the surface of concrete would be the hardest. I've noticed that it's more difficult to drill holes in old concrete than new concrete. ^_^

[8~{} Uncle Hard Monster

Francis AKA "Hurry up" Crowe, chief engineer of the Hoover Dam, came up with the idea to
run cooling pipes through the concrete sections as they were poured. Had it not been cooled with
river water followed by chilled water, it is estimated that it would have taken 125 years to
cure, and it would have cured improperly.

Cousin Cool Monster

On Tuesday, April 19, 2016 at 9:45:03 PM UTC-5, DerbyDad03 wrote:
On Tuesday, April 19, 2016 at 9:22:30 PM UTC-4, Uncle Monster wrote:
On Tuesday, April 19, 2016 at 7:38:55 PM UTC-5, Stormin Mormon wrote:
April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?
--
.
I believe concrete cures from the surface in. I recall reading that the concrete at Hoover Dam is still curing. It seems to me that the surface of concrete would be the hardest. I've noticed that it's more difficult to drill holes in old concrete than new concrete. ^_^

[8~{} Uncle Hard Monster

Francis AKA "Hurry up" Crowe, chief engineer of the Hoover Dam, came up with the idea to
run cooling pipes through the concrete sections as they were poured. Had it not been cooled with
river water followed by chilled water, it is estimated that it would have taken 125 years to
cure, and it would have cured improperly.

Cousin Cool Monster

Yea, I remember reading that but I recall reading that the concrete is still curing or getting harder. ^_^

[8~{} Uncle Dam Monster

On 4/19/2016 9:12 PM, Mayayana wrote:
| Are the surfaces of cement harder? Or does the tip
| of the bit heat up and work better when it's hot?
|

No. Better to cool it with some water. You may have
hit a pebble. Concrete can vary a great deal in terms
of hardness. Some is soft. Some is nearly impossible
to get through.


Interesting. I remember all four were about the
same. Slow going at first, and then the speed
improved.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 4/19/2016 9:21 PM, Gordon Shumway wrote:
On Tue, 19 Apr 2016 20:38:50 -0400, Stormin Mormon wrote:

April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.


I have no idea about the relative hardness of specific areas of concrete, but what size bit were you really using?


Total brain failure. Sorry. 3/32, which was smaller
than 1/4. It's the bit that is sold for 1/4 tapcons.
My apologies to the gentle readers of this list.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 4/19/2016 10:39 PM, wrote:
Seriously, the very surface often has more portland cement because of
troweling. So, it may be a little harder. Also, the rock may be quite a
bit softer, but that depends on where the quarry is located. Your bit is
going thru stones, sand, and the actual cement. So there will be a lot
of variances as you drill thru it. Also, some concrete blends are harder
than others. It depends on how much portland cement is added, and in the
case of precast concrete, it's harder yet, based on other additives.
Dont forget, you could drill thru rebar and wire mesh too.

You DO NOT want your bits getting hot. Run a slow trickle of water as
you drill.


Well, that makes sense. Might been different
hardness, near the surface.

In this case (four holes, about 1/2 inch deep,
timed about ten minutes apart), not much chance
of over heating a drill bit.

I'm guessing if I set up a garden hose or some
cooling system, the church would not be pleased
with all the water and cement dust running down
the class room walls.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 4/19/2016 10:44 PM, DerbyDad03 wrote:
Francis AKA "Hurry up" Crowe, chief engineer of the Hoover Dam, came up with the idea to
run cooling pipes through the concrete sections as they were poured. Had it not been cooled with
river water followed by chilled water, it is estimated that it would have taken 125 years to
cure, and it would have cured improperly.

Cousin Cool Monster


So, cool cement cures faster? I didn't
know that. Thanks.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

Stormin Mormon wrote:
April 19, 2016

Today I installed five clocks, four were on cinder
block wall. Using small platic anchors, and a 1/36
masonary bit in a high speed hammer drill.

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder? Or does the tip
of the bit heat up and work better when it's hot?

Remember that he tip of the bit - the cutting part - is "V" shaped. When
you first start drilling, only the very tip is in contact with the concrete
and the going is slow. As you go deeper, more and more cutting surface is
in contact and the cutting is faster.

On 4/20/2016 7:10 AM, dadiOH wrote:
Remember that he tip of the bit - the cutting part - is "V" shaped. When
you first start drilling, only the very tip is in contact with the concrete
and the going is slow. As you go deeper, more and more cutting surface is
in contact and the cutting is faster.


Maks more sense than most ideas. Might
be the correct one.


--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Wednesday, April 20, 2016 at 7:10:03 AM UTC-4, Stormin Mormon wrote:
On 4/19/2016 10:44 PM, DerbyDad03 wrote:
Francis AKA "Hurry up" Crowe, chief engineer of the Hoover Dam, came up with the idea to
run cooling pipes through the concrete sections as they were poured. Had it not been cooled with
river water followed by chilled water, it is estimated that it would have taken 125 years to
cure, and it would have cured improperly.

Cousin Cool Monster


So, cool cement cures faster? I didn't
know that. Thanks.


#1 - No, that is not correct and I take the blame for that misunderstanding.
I need to correct something I posted earlier.

I said:

"...it is estimated that it would have taken 125 years to cure..."

What I should have said is:

"...it is estimated that it would have taken 125 years to *cool*..."

The uneven cooling is the issue, as explained below.

#2 - The Hoover Dam is made of *concrete* not (just) cement. I say (just)
because cement is one of the ingredients in concrete. Cement alone cannot be
used for a structure like a dam.

#3 - I'm not a concrete expert, but if I understand the process correctly,
the use of the cooling water is to aid in a more even cure, not a faster
cure.

Stolen without permission from:

http://www.concretenetwork.com/curin...is-curing.html

"The other important aspect of curing is temperature--the concrete can't be
too cold or too hot. As fresh concrete gets cooler, the hydration reaction
slows down. The temperature of the concrete is what's important here, not
necessarily the air temperature. Below about 50 F, hydration slows down a
lot; below about 40 F, it virtually stops.

Hot concrete has the opposite problem: the reaction goes too fast, and since
the reaction is exothermic (produces heat), it can quickly cause temperature
differentials within the concrete that can lead to cracking. And cement that
reacts too quickly doesn't have time for the crystals to grow properly so it
doesn't develop as much strength as it should."

On 4/20/2016 9:24 AM, DerbyDad03 wrote:
On Wednesday, April 20, 2016 at 7:10:03 AM UTC-4, Stormin Mormon wrote:
On 4/19/2016 10:44 PM, DerbyDad03 wrote:
Francis AKA "Hurry up" Crowe, chief engineer of the Hoover Dam, came up with the idea to
run cooling pipes through the concrete sections as they were poured. Had it not been cooled with
river water followed by chilled water, it is estimated that it would have taken 125 years to
cure, and it would have cured improperly.

Cousin Cool Monster


So, cool cement cures faster? I didn't
know that. Thanks.


#1 - No, that is not correct and I take the blame for that misunderstanding.
I need to correct something I posted earlier.

I said:

"...it is estimated that it would have taken 125 years to cure..."

What I should have said is:

"...it is estimated that it would have taken 125 years to *cool*..."

The uneven cooling is the issue, as explained below.

#2 - The Hoover Dam is made of *concrete* not (just) cement. I say (just)
because cement is one of the ingredients in concrete. Cement alone cannot be
used for a structure like a dam.

#3 - I'm not a concrete expert, but if I understand the process correctly,
the use of the cooling water is to aid in a more even cure, not a faster
cure.

Stolen without permission from:

http://www.concretenetwork.com/curin...is-curing.html

"The other important aspect of curing is temperature--the concrete can't be
too cold or too hot. As fresh concrete gets cooler, the hydration reaction
slows down. The temperature of the concrete is what's important here, not
necessarily the air temperature. Below about 50 F, hydration slows down a
lot; below about 40 F, it virtually stops.

Hot concrete has the opposite problem: the reaction goes too fast, and since
the reaction is exothermic (produces heat), it can quickly cause temperature
differentials within the concrete that can lead to cracking. And cement that
reacts too quickly doesn't have time for the crystals to grow properly so it
doesn't develop as much strength as it should."


Thanks for the correction. Nice to have good
info, on things. I've not done much work with
cement or concrete. But, someone out there has.
And, that's a good thing.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 4/20/2016 9:24 AM, DerbyDad03 wrote:
What I should have said is:

"...it is estimated that it would have taken 125 years to *cool*..."

The uneven cooling is the issue, as explained below.

#2 - The Hoover Dam is made of *concrete* not (just) cement. I say (just)
because cement is one of the ingredients in concrete. Cement alone cannot be
used for a structure like a dam.


I wonder how many years it would take me to
install a clock on the Hoover dam? Guess I'd
have to use a masonary bit?

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Wednesday, April 20, 2016 at 12:03:12 PM UTC-4, Stormin Mormon wrote:
On 4/20/2016 9:24 AM, DerbyDad03 wrote:
What I should have said is:

"...it is estimated that it would have taken 125 years to *cool*..."

The uneven cooling is the issue, as explained below.

#2 - The Hoover Dam is made of *concrete* not (just) cement. I say (just)
because cement is one of the ingredients in concrete. Cement alone cannot be
used for a structure like a dam.


I wonder how many years it would take me to
install a clock on the Hoover dam? Guess I'd
have to use a masonary bit?


I thought you already took care of it...twice.

http://www.informedchristians.com/ar...over_dam_6.jpg

Isn't this you installing the clocks?

http://www.djwriter.com/cycling/dayr.../HDStatue2.jpg

On 4/20/2016 12:16 PM, DerbyDad03 wrote:
On Wednesday, April 20, 2016 at 12:03:12 PM UTC-4, Stormin Mormon wrote:
I wonder how many years it would take me to
install a clock on the Hoover dam? Guess I'd
have to use a masonary bit?


I thought you already took care of it...twice.

http://www.informedchristians.com/ar...over_dam_6.jpg

Isn't this you installing the clocks?

http://www.djwriter.com/cycling/dayr.../HDStatue2.jpg


Sigh. I guess nothing secret, any more?

You got me.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Wed, 20 Apr 2016 06:24:40 -0700 (PDT), DerbyDad03
wrote:

What I should have said is:

"...it is estimated that it would have taken 125 years to *cool*..."

.... for a single monolithic pour

https://en.wikipedia.org/wiki/Hoover_Dam#Concrete

It was poured in rectangle columns...instead.

Pic:

https://upload.wikimedia.org/wikipedia/commons/3/3d/Damforms.jpg

On Wednesday, April 20, 2016 at 1:18:01 PM UTC-4, Oren wrote:
On Wed, 20 Apr 2016 06:24:40 -0700 (PDT), DerbyDad03
wrote:

What I should have said is:

"...it is estimated that it would have taken 125 years to *cool*..."

... for a single monolithic pour

Yes, but even the small - relatively speaking, of course - ;-) blocks
needed to be cooled to prevent uneven curing.


https://en.wikipedia.org/wiki/Hoover_Dam#Concrete

It was poured in rectangle columns...instead.

Pic:

https://upload.wikimedia.org/wikipedia/commons/3/3d/Damforms.jpg

They used a similar technique to build the Three Gorges Dam in China.

If that dam ever fails, there are a lot of people that will get very, very
wet. The White Water Rafting industry would do pretty well though. ;-)

On Wed, 20 Apr 2016 09:16:59 -0700 (PDT), DerbyDad03
wrote:

I wonder how many years it would take me to
install a clock on the Hoover dam? Guess I'd
have to use a masonary bit?


I thought you already took care of it...twice.

http://www.informedchristians.com/ar...over_dam_6.jpg

Only one of those clocks observes DST in Spring/Fall. Nevada wants
off DST and changing clocks twice a year.

Stormin Mormon wrote in :

[...]

What I noticed, after about 1/8 or so into the wall,
the bit progress was a bit faster. Took a lot of
work to get the first 1/4 inch or so.

Are the surfaces of cement harder?

Yes. Concrete continues to harden for decades, by absorbing carbon dioxide from the air.
This obviously happens from the outside in, and, yes, the outside *is* harder than the inside.