It can work, because what you are trying to do is not to move a
lot
of air and sand, but try to make some noise. And you don't have to
move a whole lot of sand to do that. As long as the pipes stay
together, some air will make it out of the open end and make some
noise.


Yes, making noise was key in locating my underground PVC. In my case,
I was able to locate the end by listening closely NEAR where I thought it
should have been while someone else was running a snake fully inserted in
the pvc back and forth a few inches.... the noise it made at the last
sweep was evident with no other background noise to interfere with it.

Ed K7AAT

Ed wrote:
It can work, because what you are trying to do is not to move a
lot
of air and sand, but try to make some noise. And you don't have to
move a whole lot of sand to do that. As long as the pipes stay
together, some air will make it out of the open end and make some
noise.


Yes, making noise was key in locating my underground PVC. In my case,
I was able to locate the end by listening closely NEAR where I thought it
should have been while someone else was running a snake fully inserted in
the pvc back and forth a few inches.... the noise it made at the last
sweep was evident with no other background noise to interfere with it.


And if Jimmie will let us borrow his dog, we'll be all set!

- 73 de Mike N3LI -

After making a post early on this topic, what goes around came around
and I had to identify a coax that passed under the driveway... Ye old
wire tracer and 30 seconds is all it took to find it...

denny - k8do

On Oct 23, 12:02*am, "Jerry" wrote:
"JIMMIE" wrote in message

...
On Oct 15, 1:17 am, Ed wrote:





I know this is slightly off topic, but since I am intending to run
some RF cable in the conduit, and since there are a lot of intelligent
hams on this group, I will proceed anyway:

Last year at the beginning of construction of a new house I buried
about 50 feet of 3/4" Sched. 40 PVD between the house and a location on
the property perimeter. Now that I am ready to use it, I can not
locate the perimeter end.... it is somewhere in about a 10' area, and the
end curves up to probably about a foot underground.

The ground is nearly pure sand, and is well landscaped now to the
point that I do not want to randomly dig it up.

The end terminated in an elbow curving up and is well duct taped
shut.

Can anyone suggest a method or equipment I might use to locate that
far end?

Tnx.

Ed K7AAT

I have some pipe that I had run for an outdoor spigot that I never
finished installing. *To test a method of finding it I shot some air
into it the other end was pretty easy to find by listening. I could
hear the rush of air and a lot of gurgling. My dog actually found it
in the roses bushes before I did.

Jimmie

* Hi Jimmie

* That "air" idea wont work, Jeff told me so

* Quote Jeff --

"Welcome to rec.radio.amateur.antenna.physics

Ok, let's do the math. *Dry sand weighs 100 lb/cubic-foot. *There's
about 1 ft of sand above the end of the 3/4" conduit. *The weight
action is roughly conical, so the volume of sand involved is (my
guess) about:
* 100 lbs/ft^3 * 1/3 = 33 lbs of sand.
All that it acting on a 3/4" diameter pipe, with a cross sectional
area of about:
* Pi * 0.75" = 2.4 in^2
Therefore, the pressure exerted by the sand is:
* 33 lbs / 2.4 in^2 = 14 PSI
So, if he can pressurize the pipe to more than 14 PSI, he can lift the
column of sand sufficiently to keep it from dribbling into the pipe.

Of course, it's not that simple. *Laminar air flow, pressure gradients
across the conduit, and the effects of the duct tape will ruin my
simplistic guesswork. *Worse, the back pressure created by the
immovable column of sand will force some sand particles into the
conduit around the edges with the "reflected" air pressure. *In the
middle of the conduit, the air flow is all out of the conduit, but
near the edges, it could easily be the other direction. *I'm also
assuming that the sand is a perfect air seal, which it's not. *To
prevent all this from happening, the minimum air pressure should be
about twice the 14 PSI, which is easily achievable with an air
compressor, but not a vacuum cleaner.

I'm also trying to imagine how the process will work. *I see an air
compressor pumping madly away as the neighbors kids furiously dig
around the resultant sand volcano, as sand rapidly refills the conical
hole. *In my never humble opinion, there's no way to prevent sand from
dropping into the conduit if the duct tape seal is broken before
excavating the end of the conduit.

Once the sand is in the conduit, just blowing air through the pipe
isn't going to magically elevate the sand particles 1ft or more in the
air. *The air does not have sufficient mass to convey enough momentum
to move the sand particles, much less eject them vertically. *For
that, one needs a denser medium, such as water. *Shoving a plunger
through might work, but it's equally likely to jam sand particles into
the PVC conduit walls.

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558"

* * * * *Jerry * KD6JDJ- Hide quoted text -

- Show quoted text -

Obviously you're an engineer. LOL

Jimmie

"Michael Coslo" wrote in message
...
Jerry wrote:
"JIMMIE" wrote in message

...
On Oct 15, 1:17 am, Ed wrote:
I know this is slightly off topic, but since I am intending to run
some RF cable in the conduit, and since there are a lot of intelligent
hams on this group, I will proceed anyway:

Last year at the beginning of construction of a new house I buried
about 50 feet of 3/4" Sched. 40 PVD between the house and a location on
the property perimeter. Now that I am ready to use it, I can not
locate the perimeter end.... it is somewhere in about a 10' area, and
the
end curves up to probably about a foot underground.

The ground is nearly pure sand, and is well landscaped now to the
point that I do not want to randomly dig it up.

The end terminated in an elbow curving up and is well duct taped
shut.

Can anyone suggest a method or equipment I might use to locate that
far end?

Tnx.

Ed K7AAT

I have some pipe that I had run for an outdoor spigot that I never
finished installing. To test a method of finding it I shot some air
into it the other end was pretty easy to find by listening. I could
hear the rush of air and a lot of gurgling. My dog actually found it
in the roses bushes before I did.

Jimmie

Hi Jimmie

That "air" idea wont work, Jeff told me so

Quote Jeff --

"Welcome to rec.radio.amateur.antenna.physics

It can work, because what you are trying to do is not to move a lot
of air and sand, but try to make some noise. And you don't have to move
a whole lot of sand to do that. As long as the pipes stay together, some
air will make it out of the open end and make some noise.

And where is the air going to escape? He said he duct-taped the end shut.
With enough pressure, he'll have a blow-out, but that could also result in
getting dirt inside the pipe, which I believe wouldn't be good. However,
short of that, there's no hole for the air make noise....

He knows the length and direction. He should be able to make an educated
guess as where to dig.

"D. Stussy" wrote in message
...
"Michael Coslo" wrote in message
...
Jerry wrote:
"JIMMIE" wrote in message

...
On Oct 15, 1:17 am, Ed wrote:
I know this is slightly off topic, but since I am intending to run
some RF cable in the conduit, and since there are a lot of intelligent
hams on this group, I will proceed anyway:

Last year at the beginning of construction of a new house I buried
about 50 feet of 3/4" Sched. 40 PVD between the house and a location
on
the property perimeter. Now that I am ready to use it, I can not
locate the perimeter end.... it is somewhere in about a 10' area, and
the
end curves up to probably about a foot underground.

The ground is nearly pure sand, and is well landscaped now to the
point that I do not want to randomly dig it up.

The end terminated in an elbow curving up and is well duct taped
shut.

Can anyone suggest a method or equipment I might use to locate that
far end?

Tnx.

Ed K7AAT

I have some pipe that I had run for an outdoor spigot that I never
finished installing. To test a method of finding it I shot some air
into it the other end was pretty easy to find by listening. I could
hear the rush of air and a lot of gurgling. My dog actually found it
in the roses bushes before I did.

Jimmie

Hi Jimmie

That "air" idea wont work, Jeff told me so

Quote Jeff --

"Welcome to rec.radio.amateur.antenna.physics

It can work, because what you are trying to do is not to move a lot
of air and sand, but try to make some noise. And you don't have to move
a whole lot of sand to do that. As long as the pipes stay together, some
air will make it out of the open end and make some noise.

And where is the air going to escape? He said he duct-taped the end shut.
With enough pressure, he'll have a blow-out, but that could also result in
getting dirt inside the pipe, which I believe wouldn't be good. However,
short of that, there's no hole for the air make noise....

He knows the length and direction. He should be able to make an educated
guess as where to dig.

Hi D

You and Jeff may know something I didnt realize about sealing. I cant
imagine being able to make duct tape seal off the open end of a PVC pipe
with tuct tape, How much pressure can be sealed with the tape on the side
of the PVC? I would have expected the tape to have been applied to prevent
sand from entering. That wouldnt seal against much air pressure.
Furthermore, it is very easy to apply only adequate pressure to initiate
some air flow , not a sudden blast at high pressure to cause a crater. As
you know, a small amount of air flowing thru a small passage can produce
plenty of sound.
You are right, he has found the end of the pipe. I am curious to know
why it is necessary to write that the air leak method *wont* work when I am
sure it will work, Jimmy has demonstrated that.

Jerry

On Oct 23, 7:02*pm, "Jerry" wrote:
"D. Stussy" wrote in message

...





"Michael Coslo" wrote in message
...
Jerry wrote:
"JIMMIE" wrote in message

....
On Oct 15, 1:17 am, Ed wrote:
I know this is slightly off topic, but since I am intending to run
some RF cable in the conduit, and since there are a lot of intelligent
hams on this group, I will proceed anyway:

Last year at the beginning of construction of a new house I buried
about 50 feet of 3/4" Sched. 40 PVD between the house and a location
on
the property perimeter. Now that I am ready to use it, I can not
locate the perimeter end.... it is somewhere in about a 10' area, and
the
end curves up to probably about a foot underground.

The ground is nearly pure sand, and is well landscaped now to the
point that I do not want to randomly dig it up.

The end terminated in an elbow curving up and is well duct taped
shut.

Can anyone suggest a method or equipment I might use to locate that
far end?

Tnx.

Ed K7AAT

I have some pipe that I had run for an outdoor spigot that I never
finished installing. *To test a method of finding it I shot some air
into it the other end was pretty easy to find by listening. I could
hear the rush of air and a lot of gurgling. My dog actually found it
in the roses bushes before I did.

Jimmie

* Hi Jimmie

* That "air" idea wont work, Jeff told me so

* Quote Jeff --

"Welcome to rec.radio.amateur.antenna.physics

It can work, because what you are trying to do is not to move a * lot
of air and sand, but try to make some noise. And you don't have to move
a whole lot of sand to do that. As long as the pipes stay together, some
air will make it out of the open end and make some noise.

And where is the air going to escape? *He said he duct-taped the end shut.
With enough pressure, he'll have a blow-out, but that could also result in
getting dirt inside the pipe, which I believe wouldn't be good. *However,
short of that, there's no hole for the air make noise....

He knows the length and direction. *He should be able to make an educated
guess as where to dig.

* Hi D

* You and Jeff may know something I didnt realize about sealing. * I cant
imagine being able to make duct tape seal off the open end of a PVC pipe
with tuct tape, * How much pressure can be *sealed with the tape on the side
of the PVC? * I would have expected the tape to have been applied to prevent
sand from entering. That wouldnt seal against much air pressure.
Furthermore, it is very easy to apply only adequate pressure to initiate
some air flow , not a sudden blast at high pressure to cause a crater. *As
you know, a small amount of air flowing thru a small passage can produce
plenty of sound.
* You are right, he has found the end of the pipe. * I am curious to know
why it is necessary to write that the air leak method *wont* work when I am
sure it will work, Jimmy has demonstrated that.

* * * * * * * *Jerry



- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

I must admit that sand could get into the pipe but I cant see that
would be all that bad. My pipe had water in it that is really why I
was able to find it. If i want to clean it out I would just blow some
strips of cloth through it or in the case of sand rinse it out with
water then dry it out with warm air. Shop vacs are great for this. I
should have left the damned thing alone. Now my wife wants me to
finish putting in the spigot. She gave me a Thanksgiving suspense
date.


Jimmie

"Jerry" wrote in message
...
"D. Stussy" wrote in message
...
"Michael Coslo" wrote in message
...
Jerry wrote:
"JIMMIE" wrote in message


...
On Oct 15, 1:17 am, Ed wrote:
I know this is slightly off topic, but since I am intending to run
some RF cable in the conduit, and since there are a lot of
intelligent
hams on this group, I will proceed anyway:

Last year at the beginning of construction of a new house I buried
about 50 feet of 3/4" Sched. 40 PVD between the house and a location
on
the property perimeter. Now that I am ready to use it, I can not
locate the perimeter end.... it is somewhere in about a 10' area,
and
the
end curves up to probably about a foot underground.

The ground is nearly pure sand, and is well landscaped now to the
point that I do not want to randomly dig it up.

The end terminated in an elbow curving up and is well duct taped
shut.

Can anyone suggest a method or equipment I might use to locate that
far end?

Tnx.

Ed K7AAT

I have some pipe that I had run for an outdoor spigot that I never
finished installing. To test a method of finding it I shot some air
into it the other end was pretty easy to find by listening. I could
hear the rush of air and a lot of gurgling. My dog actually found it
in the roses bushes before I did.

Jimmie

Hi Jimmie

That "air" idea wont work, Jeff told me so

Quote Jeff --

"Welcome to rec.radio.amateur.antenna.physics

It can work, because what you are trying to do is not to move a lot
of air and sand, but try to make some noise. And you don't have to move
a whole lot of sand to do that. As long as the pipes stay together,
some
air will make it out of the open end and make some noise.

And where is the air going to escape? He said he duct-taped the end
shut.
With enough pressure, he'll have a blow-out, but that could also result
in
getting dirt inside the pipe, which I believe wouldn't be good.
However,
short of that, there's no hole for the air make noise....

He knows the length and direction. He should be able to make an
educated
guess as where to dig.

Hi D

You and Jeff may know something I didnt realize about sealing. I cant
imagine being able to make duct tape seal off the open end of a PVC pipe
with tuct tape, How much pressure can be sealed with the tape on the
side
of the PVC? I would have expected the tape to have been applied to
prevent
sand from entering. That wouldnt seal against much air pressure.
Furthermore, it is very easy to apply only adequate pressure to initiate
some air flow , not a sudden blast at high pressure to cause a crater. As
you know, a small amount of air flowing thru a small passage can produce
plenty of sound.
You are right, he has found the end of the pipe. I am curious to know
why it is necessary to write that the air leak method *wont* work when I
am
sure it will work, Jimmy has demonstrated that.

Well, let's see:

3/4" pipe, and duct tape is usually 2" wide. That means the entire end will
be covered with a single piece with its sides folded down. Duct tape is
designed NOT to let air pass. That means there's a good chance that the
seal was air-tight.

Yes, making noise was key in locating my underground PVC. In my
case,
I was able to locate the end by listening closely NEAR where I thought it
should have been while someone else was running a snake fully inserted in
the pvc back and forth a few inches.... the noise it made at the last
sweep was evident with no other background noise to interfere with it.

Ed K7AAT

Congrats!

That's probably the best answer, as you are going to fish something or not
and it's always more expedient to use the most handy tool first before
hauling out the hardware store or the drawing board. This is how it usually
plays out, that there is plenty of noise when you are trying to bang the
fishtape past the 90's. This is how I learned to use 45 degree sweeps and
pull boxes at every opportunity. Anything to avoid the frustration of
breaking wire or fish tape and wasting my own time.

You and Jeff may know something I didnt realize about sealing. I
cant
imagine being able to make duct tape seal off the open end of a PVC
pipe with tuct tape, How much pressure can be sealed with the tape
on the side of the PVC? I would have expected the tape to have been
applied to prevent sand from entering. That wouldnt seal against much
air pressure.

For the record, I duct taped the end well, when it was initially
buried, in order to keep out sand and even water. It was applied well
enough to prevent any reasonable air pressure from moving it, in my
opinion. Duct Tape is awful sturdy stuff, and sticks quite well, too.

As I already said earlier, a bunch of you guys posted some excellent
ideas I could have used.... and I probably would have if my first simple
try with making noise with my fish tape hadn't worked.

Thanks again to all.

Ed K7AAT