"Ignoramus677" wrote in message
. ..
I am confused as to what happens when concrete nails are shot into
concrete with nail shooting guns. Why don't the nails get bent? Where
does the concrete that is displaced from the hole, go? Why would the
incompressible nail hold in incompressible concrete and not fall out
of its hole?

1) Concrete is not incompressible. It's somewhat porous, and will crush
under the insertion force of the nail.

2) the nail is not incompressible, at least in the sense you suspect. It
will be shrunk in diameter as it's forced into the hole it's making. But
because it is somewhat elastic, it will still present significant expansion
force in the hole.

3) it doesn't bend because it is driven in very straight. A column is a
strong form.

Sometimes power nails do bend, and sometimes even curl out of the work and
go flying.

LLoyd

Ignoramus677 wrote:
I am confused as to what happens when concrete nails are shot into
concrete with nail shooting guns. Why don't the nails get bent? Where
does the concrete that is displaced from the hole, go? Why would the
incompressible nail hold in incompressible concrete and not fall out
of its hole?

i

Concrete is less compressible than wood, but not incompressible

"Ignoramus677" wrote in message
. ..
I am confused as to what happens when concrete nails are shot into
concrete with nail shooting guns. Why don't the nails get bent? Where
does the concrete that is displaced from the hole, go? Why would the
incompressible nail hold in incompressible concrete and not fall out
of its hole?

i


The nails are heat treated, so are far more robust than are common nails.
The high speed appears to allow the nail to go where they otherwise
wouldn't, but it's not fool-proof. I use one of the simple Remington power
hammers for nailing to concrete and have had mixed results. Occasionally
you'll hit a rock that is so hard the nail won't go to prescribed depth, or
it hits nothing but soft rock or sand it will go too deep. Nailing
through an electrical knockout with a stronger charge often helps control
the depth. If nothing else, it provides a larger area for the nail head to
insure the board stays where intended.

I don't subscribe to the theory that concrete is incompressible. It has a
given amount of air space by its nature, and is rarely stronger than, say,
4,000 psi in compression, and generally not that strong. I get the idea
that the nail, driven at much higher pressure than that, easily compresses
the concrete in the proximity of the nail. When you get the desired
results, the nails hold quite well, so I can't help but think I'm on the
right track with my thinking. Do bear in mind you're talking to a high
school graduate with no mathematical training, and no engineering schooling.
It will be interesting to hear from those in the know.

Harold

Apart from the other answers it may also be down to the strain rate
sensitivity of the nail material. Although I don't know much about it
its basically that under a high rate of strain the material may behave
as though it stiffer than you would normally expect. This was mentioned
to me regarding armour piercing shells and the like.

Ignoramus677 wrote:

I am confused as to what happens when concrete nails are shot into
concrete with nail shooting guns. Why don't the nails get bent? Where
does the concrete that is displaced from the hole, go? Why would the
incompressible nail hold in incompressible concrete and not fall out
of its hole?

i

"Ignoramus677" wrote in message
. ..
| I am confused as to what happens when concrete nails are shot into
| concrete with nail shooting guns. Why don't the nails get bent? Where
| does the concrete that is displaced from the hole, go? Why would the
| incompressible nail hold in incompressible concrete and not fall out
| of its hole?
|
| i

If the concrete is a day or two old you can use a regular carpenter's
hammer, and for the next three weeks or so a power nailer will do just fine,
but after a few years you'd likely be better off boring holes. That's
pretty much been my experience, but YMMV.

carl mciver wrote:

"Ignoramus677" wrote in message
...
| I am confused as to what happens when concrete nails are shot into
| concrete with nail shooting guns. Why don't the nails get bent? Where
| does the concrete that is displaced from the hole, go? Why would the
| incompressible nail hold in incompressible concrete and not fall out
| of its hole?
|
| i

If the concrete is a day or two old you can use a regular carpenter's
hammer, and for the next three weeks or so a power nailer will do just fine,
but after a few years you'd likely be better off boring holes. That's
pretty much been my experience, but YMMV.



Yeah, you ain't kidding! I have some of the hardest concrete I've ever
seen.
Powder-actuated nailers do NOTHING to this stuff except chip the surface
a little. This place is now 30 years old, and the aggregate is all Jasper,
a round, reddish rock that is slightly less hard than diamond, apparently.
Carbide drills bounce off it, and follow a meandering path between the
jasper rocks. If you want to set an anchor in it, you have to stop drilling
every 30 seconds, squirt water to remove the dust, figure out which piece
of stone is deflecting the drill and smash it with a star drill and a 5 Lb
hammer, and then drill a little more. It is a royal pain. I've even been
trying to make my own diamond core drills to make anchor holes less than
an all-day project PER HOLE! (Some people have said to rent a Hilti or
Bosch professional-grade drill, and I will have to try that the next time
I need to mount something on the wall.)

Jon

On Fri, 19 Aug 2005 20:03:58 GMT, carl mciver wrote:

If the concrete is a day or two old you can use a regular carpenter's
hammer, and for the next three weeks or so a power nailer will do just fine,
but after a few years you'd likely be better off boring holes. That's
pretty much been my experience, but YMMV.

I've power-nailed into 5 year old Spancrete without trouble.

"Dave Hinz" wrote in message
...
On Fri, 19 Aug 2005 20:03:58 GMT, carl mciver
wrote:

If the concrete is a day or two old you can use a regular carpenter's
hammer, and for the next three weeks or so a power nailer will do just
fine,
but after a few years you'd likely be better off boring holes. That's
pretty much been my experience, but YMMV.

I've power-nailed into 5 year old Spancrete without trouble.

Dave, I go ya one better. We re-modeled a thirty year old poured-in-place,
three story IBEW building into a computer programmer's office farm.
Power-nailed all the plates. No problems, but we did have to use heavy
loads.

The bigger problem was core-drilling all the beams to route network wiring!


LLoyd

As others have stated, the nails are heat-treated for this specific
application. Don't try it with common bright nails. Older concrete
does tend to spall or shatter, making hole-drilling preferable. A
rotary hammer is then the preferred tool.
I once had to mount PT 2x4 to steel pipe (approx. 1/4" wall) that
appeared to be used drill stem. As long as I used the heaviest loads,
a washer to limit penetration and hit the pipe squarely, it would
secure the 2x4 to the pipe in order to mount a gate latch. There was
nowhere else to go - the existing gate ended at the pipe and the pipe
was at the corner of the fence line. It worked fine with about 1/2"
penetration.

On Fri, 19 Aug 2005 17:13:50 GMT, Ignoramus677
wrote:

I am confused as to what happens when concrete nails are shot into
concrete with nail shooting guns. Why don't the nails get bent? Where
does the concrete that is displaced from the hole, go? Why would the
incompressible nail hold in incompressible concrete and not fall out
of its hole?

i

carl mciver wrote:
"Ignoramus677" wrote in message
. ..
| I am confused as to what happens when concrete nails are shot into
| concrete with nail shooting guns. Why don't the nails get bent? Where
| does the concrete that is displaced from the hole, go? Why would the
| incompressible nail hold in incompressible concrete and not fall out
| of its hole?
|
| i

If the concrete is a day or two old you can use a regular carpenter's
hammer, and for the next three weeks or so a power nailer will do just fine,
but after a few years you'd likely be better off boring holes. That's
pretty much been my experience, but YMMV.

Yea tell me about it. :-) While at the university I had the unplesant
task of "trying" to mount a few brackets to a poured concrete wall.
It was in the chemistry building, about 50 yrs old. I think they
must have used better concrete mix back then also. :-) Couldn't even
drill 1/4 in. holes with a hammer drill.
...lew...

"Thomas Kendrick" wrote in message
news:1124485789.b992f196925bf9b7d5b8e542557ea88c@t eranews...
As others have stated, the nails are heat-treated for this specific
application. Don't try it with common bright nails. Older concrete
does tend to spall or shatter, making hole-drilling preferable. A
rotary hammer is then the preferred tool.
I once had to mount PT 2x4 to steel pipe (approx. 1/4" wall) that
appeared to be used drill stem. As long as I used the heaviest loads,
a washer to limit penetration and hit the pipe squarely, it would
secure the 2x4 to the pipe in order to mount a gate latch. There was
nowhere else to go - the existing gate ended at the pipe and the pipe
was at the corner of the fence line. It worked fine with about 1/2"
penetration.


I've done commercial renovations where these are used alot ! There is a
large difference in the hardness of the concrete from job to job. These
same guns ( different pins ) are also used to shoot things onto steel, for
example to shoot a 2x plate onto the top or bottom flange of an I
beam.....They go right through 3/8" steel with a hell of a clang....


Jeff

On Fri, 19 Aug 2005 23:23:20 GMT, the opaque Ignoramus677
clearly wrote:

On Fri, 19 Aug 2005 19:13:03 -0400, Jeff Sellers wrote:
I've done commercial renovations where these are used alot ! There is a
large difference in the hardness of the concrete from job to job. These
same guns ( different pins ) are also used to shoot things onto steel, for
example to shoot a 2x plate onto the top or bottom flange of an I
beam.....They go right through 3/8" steel with a hell of a clang....

I own a Mosin Nagant rifle, and it easily shoots holes in railroad tie
support plates (about 1/2").

Hey, that's a pretty good $79.95 hole hawg, ain't it?


-----------------------------------------
Jack Kevorkian for Congressional physician!
http://www.diversify.com Wondrous Website Design
=================================================

Lew Hartswick wrote:
carl mciver wrote:
"Ignoramus677" wrote in message
. ..
I am confused as to what happens when concrete nails are shot into
concrete with nail shooting guns. Why don't the nails get bent?
Where does the concrete that is displaced from the hole, go? Why
would the incompressible nail hold in incompressible concrete and
not fall out of its hole?

i

If the concrete is a day or two old you can use a regular
carpenter's hammer, and for the next three weeks or so a power
nailer will do just fine, but after a few years you'd likely be
better off boring holes. That's pretty much been my experience, but
YMMV.
Yea tell me about it. :-) While at the university I had the unplesant
task of "trying" to mount a few brackets to a poured concrete wall.
It was in the chemistry building, about 50 yrs old. I think they
must have used better concrete mix back then also. :-) Couldn't even
drill 1/4 in. holes with a hammer drill.
...lew...

Concrete (good concrete that is) never stops getting harder. My first real
job, somewhere back before the last ice age was with a concrete pipe and
beam manufacturer.
The plant engineer managed to destroy a huge hydraulic test press when he
got the idea to put one of the old (25 year plus) test cyinders in to see
how hard it was (compressive strength).
On the subject of 'concrete' nails - they make handy little center punches
and scribers.

Ken.

In article ,
Ignoramus677 wrote:

On Fri, 19 Aug 2005 19:13:03 -0400, Jeff Sellers
wrote:
I've done commercial renovations where these are used alot ! There is a
large difference in the hardness of the concrete from job to job. These
same guns ( different pins ) are also used to shoot things onto steel, for
example to shoot a 2x plate onto the top or bottom flange of an I
beam.....They go right through 3/8" steel with a hell of a clang....

I own a Mosin Nagant rifle, and it easily shoots holes in railroad tie
support plates (about 1/2").

i


Mine's a Remington. Drills real pretty .30 holes in those plates. Kinda
noisy, though...

--
Don Bruder - - New Email policy in effect as of Feb. 21, 2004.
Short form: I'm trashing EVERY E-mail that doesn't contain a password in the
subject unless it comes from a "whitelisted" (pre-approved by me) address.
See http://www.sonic.net/~dakidd/main/contact.html for full details.

"Ken Davey" wrote in message
...
SNIP
| Concrete (good concrete that is) never stops getting harder. My first real
| job, somewhere back before the last ice age was with a concrete pipe and
| beam manufacturer.
| The plant engineer managed to destroy a huge hydraulic test press when he
| got the idea to put one of the old (25 year plus) test cyinders in to see
| how hard it was (compressive strength).
| On the subject of 'concrete' nails - they make handy little center punches
| and scribers.
|
| Ken.

That's a good idea for a punch!

Those familiar with concrete know that there are a hundred different
kinds, and each batch could be different from the next. How "hot" the mix
was, what the humidity and temperature was the day it was poured and for
awhile after, the content of the different fillers such as ash, sand, gravel
and the size of each. Slump is a way to measure how thick it is at pour.
The test is to put some in a skinny little can and lift the can away. If
the mix stands up it has low slump, and if it runs out like water its high
slump. Various engineering requirements define the mix as well as the
slump. Government projects demand low slump concrete usually, but it's a
mother to get spread properly, hence some huge vibrators used by some very
tired crews! The higher the slump the higher the water content, which
controls cure time and how soon you can use the concrete to its rated load,
as well as a number of other features. Water will spend years leaving the
concrete, so that's why the strength continues to increase. My father
informed me that when the Hoover Dam was being poured they had to pipe
chilled water through the dam for many, may years afterwards or the dam
would have exploded from the heat and steam created inside the massive
concrete layers. That boggles my mind!
I'm far from an expert on concrete, but I know just enough to get
someone else to work it for me unless I'm feeling masochistic or stupid, or
it's a tiny job. Doing concrete is a young man's game, and I'm just a bit
older than that.

"carl mciver" wrote in message
nk.net...
"Ken Davey" wrote in message
...
SNIP
| Concrete (good concrete that is) never stops getting harder. My first
real
| job, somewhere back before the last ice age was with a concrete pipe and
| beam manufacturer.
| The plant engineer managed to destroy a huge hydraulic test press when
he
| got the idea to put one of the old (25 year plus) test cyinders in to
see
| how hard it was (compressive strength).
| On the subject of 'concrete' nails - they make handy little center
punches
| and scribers.
|
| Ken.

That's a good idea for a punch!

Those familiar with concrete know that there are a hundred different
kinds, and each batch could be different from the next. How "hot" the mix
was, what the humidity and temperature was the day it was poured and for
awhile after, the content of the different fillers such as ash, sand,
gravel
and the size of each. Slump is a way to measure how thick it is at pour.
The test is to put some in a skinny little can and lift the can away. If
the mix stands up it has low slump, and if it runs out like water its high
slump. Various engineering requirements define the mix as well as the
slump. Government projects demand low slump concrete usually, but it's a
mother to get spread properly, hence some huge vibrators used by some very
tired crews! The higher the slump the higher the water content, which
controls cure time and how soon you can use the concrete to its rated
load,
as well as a number of other features. Water will spend years leaving the
concrete, so that's why the strength continues to increase. My father
informed me that when the Hoover Dam was being poured they had to pipe
chilled water through the dam for many, may years afterwards or the dam
would have exploded from the heat and steam created inside the massive
concrete layers. That boggles my mind!
I'm far from an expert on concrete, but I know just enough to get
someone else to work it for me unless I'm feeling masochistic or stupid,
or
it's a tiny job. Doing concrete is a young man's game, and I'm just a bit
older than that.

We use a concrete contractor who's about 73- still working the concrete
himself. Not all by himself, but does a significant portion of the manual
work. Don't know how he does it.

I was on a siezmic upgrade to a control tower and when I saw how they put
the cladding on the outside I stayed well away. The nails they used pierced
the columns and 3/8 wall tubes like nothing.
I was told that if the shot is not square they will shoot the nail sideways
which could kill a bystander.
Concrete nails also make good divider and trammel points. I have brazed
them onto my large homemade dividers.
Randy


"Jeff Sellers" wrote in message
...



I've done commercial renovations where these are used alot ! There is a
large difference in the hardness of the concrete from job to job. These
same guns ( different pins ) are also used to shoot things onto steel, for
example to shoot a 2x plate onto the top or bottom flange of an I
beam.....They go right through 3/8" steel with a hell of a clang....


Jeff

On Sat, 20 Aug 2005 03:28:11 GMT, the opaque Ignoramus677
clearly wrote:

On Fri, 19 Aug 2005 17:29:14 -0700, Larry Jaques novalidaddress@di wrote:
On Fri, 19 Aug 2005 23:23:20 GMT, the opaque Ignoramus677
clearly wrote:

On Fri, 19 Aug 2005 19:13:03 -0400, Jeff Sellers wrote:
I've done commercial renovations where these are used alot ! There is a
large difference in the hardness of the concrete from job to job. These
same guns ( different pins ) are also used to shoot things onto steel, for
example to shoot a 2x plate onto the top or bottom flange of an I
beam.....They go right through 3/8" steel with a hell of a clang....

I own a Mosin Nagant rifle, and it easily shoots holes in railroad tie
support plates (about 1/2").

Hey, that's a pretty good $79.95 hole hawg, ain't it?


I love it, it cost me just $70 and shoots relatively well and has mild
recoil. It is a finnish M39.

Good price! Here's a link to a MN site with lots of info.
http://www.surplusrifle.com/russianm...9130/index.asp
The Huber ball trigger mod looks like a good idea, and that
Vulcan V50 rifle on his page looks like fun.

I've been thinking it might be time to get one of these long guns to
replace Grandpa's old single-shot, bolt-action Winchester 22.

Oregon just outlawed my sinus medicine (It now takes a doctor's visit
and a prescription to get Tylenol Allergy/Sinus medicine) and with
the threat of Homeland Security, the political climate is ominous.
Ayup, we civilians will need more personal security and protection.

What do multiple case lots of 7.62x54 cartridges for that baby cost?


-----------------------------------------
Jack Kevorkian for Congressional physician!
http://www.diversify.com Wondrous Website Design
=================================================

Randy Zimmerman wrote:

I was on a siezmic upgrade to a control tower and when I saw how they put
the cladding on the outside I stayed well away. The nails they used pierced
the columns and 3/8 wall tubes like nothing.
I was told that if the shot is not square they will shoot the nail sideways
which could kill a bystander.
Concrete nails also make good divider and trammel points. I have brazed
them onto my large homemade dividers.
Randy


"Jeff Sellers" wrote in message
...

I've done commercial renovations where these are used alot ! There is a
large difference in the hardness of the concrete from job to job. These
same guns ( different pins ) are also used to shoot things onto steel, for
example to shoot a 2x plate onto the top or bottom flange of an I
beam.....They go right through 3/8" steel with a hell of a clang....


Jeff




In the High school in Arlington Texas - oh maybe in 70 or 75 - sometime in there -
they replaced the 'old' lights with the long tube lights to save money.

A week after Christmas break the lights began to tumble down. On top of students.

It seemed the standard load on the 22 shell nail guns wasn't set for the very old
and very hard concrete.

So it seems those that do it simply best pick the correct load or get the job over.

No telling who paid for it - insurance maybe.

Martin

--
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

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Had that problem in an old school building. Had to put in the anchors for a
drop ceiling, Ended up drilling every one.
Karl


"carl mciver" wrote in message
ink.net...
"Ignoramus677" wrote in message
. ..
| I am confused as to what happens when concrete nails are shot into
| concrete with nail shooting guns. Why don't the nails get bent? Where
| does the concrete that is displaced from the hole, go? Why would the
| incompressible nail hold in incompressible concrete and not fall out
| of its hole?
|
| i

If the concrete is a day or two old you can use a regular carpenter's
hammer, and for the next three weeks or so a power nailer will do just
fine,
but after a few years you'd likely be better off boring holes. That's
pretty much been my experience, but YMMV.