OK, so I've started my tunneling project (3" * 12', 5' below grade)
mentioned a few weeks back. The pipe is not comng for a week or so, but I
thought I would start to see what I was getting in to.

I cored drilled the block (2 x 4" holes) last week in 'anticipation' of the
chunnel. I assembled a few tools based on your comments last time, garden
auger, pressure washer, telescoping wand. I decided to start the hole using
my 5' installer's bit to try and get a straight line and see if there were
any obstacles 'out there'? The bit stopped at about 2'+. Damn. Next I got
out the garden auger (3"x3') to see it it was a small object I could grind
out. Nope. So I put the pressure washer to use to see what was impeding my
process? I was hoping it was a soft brick, but it appears to be part of a
concrete block at an angle to the hole.

I've tried cracking the block with a piece of rebar and a 3lb hammer, but it
just breaks little chucks off. I don't have a lot of room to swin, so it's
difficult to use a sledge hammer. Also if I just lay the rebar in the hole
it will skip over the top of the block due to the angle it's positioned. I
don't know if I can dig it out or sink it, as I'm not sure how big it is. I
guess I need a better chisel so I can really smack it. Perhaps some kind of
air chisel for my compressor.



All useful suggestions on a better approach for breaking up the obstruction
would be appreciated.

"Bill Stock" writes:

OK, so I've started my tunneling project (3" * 12', 5' below grade)
mentioned a few weeks back. The pipe is not comng for a week or so, but I
thought I would start to see what I was getting in to.

I cored drilled the block (2 x 4" holes) last week in 'anticipation' of the
chunnel. I assembled a few tools based on your comments last time, garden
auger, pressure washer, telescoping wand. I decided to start the hole using
my 5' installer's bit to try and get a straight line and see if there were
any obstacles 'out there'? The bit stopped at about 2'+. Damn. Next I got
out the garden auger (3"x3') to see it it was a small object I could grind
out. Nope. So I put the pressure washer to use to see what was impeding my
process? I was hoping it was a soft brick, but it appears to be part of a
concrete block at an angle to the hole.

Start making the hole wider.

Make sure you're not breaking into some utility line.

"Dan Espen" wrote in message
...
"Bill Stock" writes:

OK, so I've started my tunneling project (3" * 12', 5' below grade)
mentioned a few weeks back. The pipe is not comng for a week or so, but I
thought I would start to see what I was getting in to.

I cored drilled the block (2 x 4" holes) last week in 'anticipation' of
the
chunnel. I assembled a few tools based on your comments last time, garden
auger, pressure washer, telescoping wand. I decided to start the hole
using
my 5' installer's bit to try and get a straight line and see if there
were
any obstacles 'out there'? The bit stopped at about 2'+. Damn. Next I got
out the garden auger (3"x3') to see it it was a small object I could
grind
out. Nope. So I put the pressure washer to use to see what was impeding
my
process? I was hoping it was a soft brick, but it appears to be part of a
concrete block at an angle to the hole.

Start making the hole wider.

Make sure you're not breaking into some utility line.

Yeah, except my exit hole is only 4". So even if I can free 'the object' it
may not come out of the hole. I don't want to make too big a cavern in any
event, as I don't want to sink the paving stones above.

I can tell you that it's some kind of concrete and it's HARD. Likely an old
piece of wall or foundation. If it were block or brick I would have smashed
it by now. I bought a long 60" hard, heavy, pointy thing to hit it with, but
it won't budge. I think the pointy thing is a digging/rock bar. I think if I
could really swing at it, might make some progress.

My next step is to drill it and then hit it with the pointy thing again.

"Bill Stock" writes:

"Dan Espen" wrote in message
...
"Bill Stock" writes:

OK, so I've started my tunneling project (3" * 12', 5' below grade)
mentioned a few weeks back. The pipe is not comng for a week or so, but I
thought I would start to see what I was getting in to.

I cored drilled the block (2 x 4" holes) last week in 'anticipation' of
the
chunnel. I assembled a few tools based on your comments last time, garden
auger, pressure washer, telescoping wand. I decided to start the hole
using
my 5' installer's bit to try and get a straight line and see if there
were
any obstacles 'out there'? The bit stopped at about 2'+. Damn. Next I got
out the garden auger (3"x3') to see it it was a small object I could
grind
out. Nope. So I put the pressure washer to use to see what was impeding
my
process? I was hoping it was a soft brick, but it appears to be part of a
concrete block at an angle to the hole.

Start making the hole wider.

Make sure you're not breaking into some utility line.

Yeah, except my exit hole is only 4". So even if I can free 'the object' it
may not come out of the hole. I don't want to make too big a cavern in any
event, as I don't want to sink the paving stones above.

Mainly I think you want to figure out what it is.

I can tell you that it's some kind of concrete and it's HARD. Likely an old
piece of wall or foundation. If it were block or brick I would have smashed
it by now. I bought a long 60" hard, heavy, pointy thing to hit it with, but
it won't budge. I think the pointy thing is a digging/rock bar. I think if I
could really swing at it, might make some progress.

Rock bar would have been my next suggestion.
I wasn't sure you had room to use it.
They're much easier to use vertically of course.

My next step is to drill it and then hit it with the pointy thing again.

An electric hammer (like a jack hammer) is another possibility.
Rental places have them.

core drill the obstruction...........

use extensions

wrote in message
oups.com...
core drill the obstruction...........

use extensions

Yeah, I think that's my conclusion now too, but it's a $100 a shot to rent.

I discovered tonight that my 18" masonry bit would reach the obstruction,
since the nose of my hammer drill will squeeze through the hole in the
block. I managed to drill about 4 3/4" holes through it, but still can't
crack it with the rock digger. If I pound it four about ten minutes I get to
break off a small chunk. Woohoo! :-) Not to mention, the bit is now dull,
the chuck is slipping and I smacked my head on the block wall when the bit
skittered. It's OK though, both my head and the block are hollow.

On the bright side I discovered the enemy is about 4" thick and made of
fairly dense concrete, 30+ years old.

"Dan Espen" wrote in message
...

Rock bar would have been my next suggestion.
I wasn't sure you had room to use it.
They're much easier to use vertically of course.

My next step is to drill it and then hit it with the pointy thing again.

An electric hammer (like a jack hammer) is another possibility.
Rental places have them.

I wondered about an air chisel, but I did not see any bits long enough. I
guess an electric hammer is the next step up. I'll have to price them versus
a core drill (again).

"Bill Stock" wrote in message
...

"Dan Espen" wrote in message
...

Rock bar would have been my next suggestion.
I wasn't sure you had room to use it.
They're much easier to use vertically of course.

My next step is to drill it and then hit it with the pointy thing again.

An electric hammer (like a jack hammer) is another possibility.
Rental places have them.

I wondered about an air chisel, but I did not see any bits long enough. I
guess an electric hammer is the next step up. I'll have to price them
versus a core drill (again).


I guess abandoning that hole and starting another nearby is not an option?
You should be able to fill up the original hole okay.

Don Young

"Bill Stock" wrote:

-snip-
I wondered about an air chisel, but I did not see any bits long enough. I
guess an electric hammer is the next step up. I'll have to price them versus
a core drill (again).


Old concrete should yield fairly easily. Any chance of welding up
some long bits for your air chisel from rebar and some sacrificial
chisels? [you mentioned you had a compressor earlier- and if you
don't have an air chisel, Harbor freight sells them for less than $20
with a 1/2 dozen chisels]

Jim