I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter

On Mar 11, 10:48*pm, wrote:
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter

You would want to use an auger bit, but at that length you will be
looking at a custom bit. Not cheap but if you DAGS "custom made auger
bit", you will find some that make them. Why does your hole have to be
that big?

Allen

On Thu, 11 Mar 2010 22:48:43 -0500, the infamous
scrawled the following:

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What does the decking have to do with drilling joists? You don't want
to pull it?


What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.

Use a 12ga extension. HF has 25' x 12ga for $10 which are nice. I use
mine all the time for their 12" SCMS. YOu don't mean 12' metal
extension, do you?!?


I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?
Augers self-feed and don't break out as hard. There are short auger
sets available if you like 'em.


Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Oh, you do mean physical, not electrical. Why don't you just unscrew
the decking and have a friend help lift it? Or did some jerk just
nail it in? grrr Ooh, flooring might be glued, too, huh? Skilsaw,
cut a long slot, lift it, replace and reglue with caulk as an
adhesive. Cost: 1 sheet of flooring. Time saved: a day. Frustration
saved: Humongous amounts.


Forgot - the hole needs to be 1 1/2 inch diameter

I'd hold my light sabre down there for a couple quick punches through,
one from each side. No extension necessary.

--
There is no such thing as limits to growth, because there are no limits
to the human capacity for intelligence, imagination, and wonder.
--Ronald Reagan

"allen476" wrote in message
...
On Mar 11, 10:48 pm, wrote:
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter

You would want to use an auger bit, but at that length you will be
looking at a custom bit. Not cheap but if you DAGS "custom made auger
bit", you will find some that make them. Why does your hole have to be
that big?

A regular auger bit on extensions should do it. It only goes threw one board
at a time.

wrote in message
...
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter


Hole saw and angle drill. One joist at a time.

On 3/12/2010 1:08 AM, LDosser wrote:
wrote in message
...
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter


Hole saw and angle drill. One joist at a time.

If I understand correctly what he wrote, he doesn't have any access--he
has to drill the first joist and then drill the second one through the
hole in the first, and so on. The difficulty seems to be the 12 feet of
extension--not extension _cord_ but bit extension.

On 3/11/2010 10:06 PM Lew Hodgett spake thus:

wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull
cable across to the center of the floor). The joists are sitting
directly on concrete, and the decking is 1 1/2" (you read that
right) plywood.

This is a TOTAL PITA solution, but it will get the job done.

Drill a 1/4" dia pilot thru every 2x8, then it is time for a 1-1/2"
hole saw AND a 1/2" right angle drill.

I wonder if you really read the OP's post. Otherwise, the only way he'd
be able to use your suggestion would be if he could scrunch his body
down to fit in a 7-1/2" high space between a concrete slab and the
decking. Quite a trick, that.

What I don't understand is when he says the joists are "only accessible
from the one side". What does this mean? That the openings between
joists are only accessible from one side of the house? I'm having a hard
time picturing this. And how the hell would he get in there in the first
place--drill a hole from the outside through the rim joist, then each
joist in turn after that?


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

On 3/11/2010 10:08 PM LDosser spake thus:

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only
from the one side. They are spaced 2 feet on centers. (need to
pull cable across to the center of the floor). The joists are
sitting directly on concrete, and the decking is 1 1/2" (you read
that right) plywood.

Hole saw and angle drill. One joist at a time.

So I'll ask you the same question I asked the other fellow who suggested
a hole saw: how the hell is this guy supposed to get into that 7-1/2"
high space to use it? You must think he's some kind of Houdini.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

"J. Clarke" wrote in message
...
On 3/12/2010 1:08 AM, LDosser wrote:
wrote in message
...
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter


Hole saw and angle drill. One joist at a time.

If I understand correctly what he wrote, he doesn't have any access--he
has to drill the first joist and then drill the second one through the
hole in the first, and so on. The difficulty seems to be the 12 feet of
extension--not extension _cord_ but bit extension.



On re-reading, it appears you are correct and I am wrong. I'd pull the
plywood!

"David Nebenzahl" wrote in message
.com...
On 3/11/2010 10:08 PM LDosser spake thus:

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only
from the one side. They are spaced 2 feet on centers. (need to
pull cable across to the center of the floor). The joists are
sitting directly on concrete, and the decking is 1 1/2" (you read
that right) plywood.

Hole saw and angle drill. One joist at a time.

So I'll ask you the same question I asked the other fellow who suggested a
hole saw: how the hell is this guy supposed to get into that 7-1/2" high
space to use it? You must think he's some kind of Houdini.


Buy a Boa?

LDosser wrote:

On re-reading, it appears you are correct and I am wrong. I'd pull the
plywood!

Or cut a strip out the entire length, and re-lay it afterwards.

--

-Mike-

On Mar 12, 12:56*am, "CW" wrote:
"allen476" wrote in message

...
On Mar 11, 10:48 pm, wrote:



On Thu, 11 Mar 2010 22:46:55 -0500, wrote:
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter

You would want to use an auger bit, but at that length you will be
looking at a custom bit. Not cheap but if you DAGS "custom made auger
bit", you will find some that make them. Why does your hole have to be
that big?

A regular auger bit on extensions should do it. It only goes threw one board
at a time.

But 10' of extensions will be the real PITA. If you don't get the set
screws tight, you'll be ripping up the floor.

Did 6' like that once. Never again.

Allen

On Fri, 12 Mar 2010 00:30:52 -0800, the infamous "LDosser"
scrawled the following:

"David Nebenzahl" wrote in message
s.com...
On 3/11/2010 10:08 PM LDosser spake thus:

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only
from the one side. They are spaced 2 feet on centers. (need to
pull cable across to the center of the floor). The joists are
sitting directly on concrete, and the decking is 1 1/2" (you read
that right) plywood.

Hole saw and angle drill. One joist at a time.

So I'll ask you the same question I asked the other fellow who suggested a
hole saw: how the hell is this guy supposed to get into that 7-1/2" high
space to use it? You must think he's some kind of Houdini.


Buy a Boa?

Yeah, a boa contractor.

--
There is no such thing as limits to growth, because there are no limits
to the human capacity for intelligence, imagination, and wonder.
--Ronald Reagan

On Fri, 12 Mar 2010 06:47:26 -0800, Larry Jaques saw and angle drill.
One joist at a time.

So I'll ask you the same question I asked the other fellow who suggested a
hole saw: how the hell is this guy supposed to get into that 7-1/2" high
space to use it? You must think he's some kind of Houdini.

How about a flex shaft driving the bit?

"Larry Jaques" wrote in message
...
On Fri, 12 Mar 2010 00:30:52 -0800, the infamous "LDosser"
scrawled the following:

"David Nebenzahl" wrote in message
rs.com...
On 3/11/2010 10:08 PM LDosser spake thus:

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only
from the one side. They are spaced 2 feet on centers. (need to
pull cable across to the center of the floor). The joists are
sitting directly on concrete, and the decking is 1 1/2" (you read
that right) plywood.

Hole saw and angle drill. One joist at a time.

So I'll ask you the same question I asked the other fellow who suggested
a
hole saw: how the hell is this guy supposed to get into that 7-1/2" high
space to use it? You must think he's some kind of Houdini.


Buy a Boa?

Yeah, a boa contractor.


No a feather boa, and take up dancing.

A spade bit might have a rough punch-through, so go slow and have
patience at the end point. Make sure the bit is sharp. I think I
would try welding a spade bit onto a 1/2" pipe and make a separate
chuck insert (fitted/welded onto a 1/2" sleeve, for the pipe) for
fitting into the drill chuck. A spade bit is a lot cheaper than an
auger bit for a one-time use (once welded).

If access space, in starting, is limited, also, the 1/2" pipe can be
in successive 24" - 36" sections. Any connecting sleeves will pass
through the 1-1/2" holes and the chuck insert fitting can be moved
back, as each successive pipe section is attached. Save the set-up
for future use (???, LOL) and use the pipe sections for pipe clamps.

Sonny

wrote in message
...

I've drilled some long applications. About 8' is the longest, and never
with the size cutter you are talking about. Depending on what you are using
for extensions gravity can be a factor also. Break out may not be all that
important depending on the application, but all bits I have used experience
break out in wood. Some worse than others.

I have lost bits and extensions inside walls and other spaces. That is
something to be avoided if you can, but there are a few of my bits still in
some of those places.

Given that you are making multiple holes through 2 by you will want to
consider that the bit will dull slightly after each penetration. To
minimize breakout you will want to have a couple bits or atleast the ability
to sharpen the cutting edges.

You may want to consider some kid of sleeve and a helper to hold the sleeve
level (or slightly above level) while you work. If you are on the clock it
may be cheaper and faster to just remove decking as some have suggested.
Even if you have to replace some of it.

wrote in message
...
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

I don't see any drill working, as the shaft diameter is always much smaller
than the drill bit. To drill 6 joists with a 1 1/2" bit means the bit will
drop about 5/8" with each hole as the shaft rests on the previous hole
bottom, 5/8" x 5 joists (I am assuming the first hole will be accurate) = 3
1/8", so you will either have to start real high on the first hole or hit
the concrete with the last hole. I cannot think of any way of getting such a
large hole drilled through so many joists in one go. Can you not go around
the ends and come in from there some how?

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

We had to drill out a boat hull for a prop shaft and ending up welding
an auger bit to a metal shaft. Had a jib for rolling the shaft and
bit to get a good weld and hold everything true. A heavy wall pipe
might work ok but we used solid. Did some grinding to be able to get
a lot of fill.

Mike M

On 3/12/2010 12:17 AM Lew Hodgett spake thus:

wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers.

"David Nebenzahl" wrote:

I wonder if you really read the OP's post. Otherwise, the only way
he'd be able to use your suggestion would be if he could scrunch his
body down to fit in a 7-1/2" high space between a concrete slab and
the decking. Quite a trick, that.

Depends how you interept thev above phrase:

" I need to drill through 6 2X8 joists which are accessible only from
the one side."

I interept that to mean he has access to one side such as floor joists
in a house with a basement.

Yabbut right after that he wrote:

The joists are sitting directly on concrete, and the decking is 1
1/2" (you read that right) plywood.

Guess you missed that part, eh?


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

On 3/12/2010 12:53 PM, EXT wrote:

wrote in message
...
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

I don't see any drill working, as the shaft diameter is always much
smaller than the drill bit. To drill 6 joists with a 1 1/2" bit means
the bit will drop about 5/8" with each hole as the shaft rests on the
previous hole bottom, 5/8" x 5 joists (I am assuming the first hole will
be accurate) = 3 1/8", so you will either have to start real high on the
first hole or hit the concrete with the last hole. I cannot think of any
way of getting such a large hole drilled through so many joists in one
go. Can you not go around the ends and come in from there some how?

Just needs a steady rest.

On Mar 11, 7:46*pm, wrote:
*I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use

Well, a drill that makes minimum sawdust uses lowest power; I'd
consider a length of black iron pipe with a tack-welded hole
saw on the end. If you support the iron pipe outboard of your
deck to be level, it should shoot straight enough to get to the
destination.

Just get a (disposable) hole saw and a 20' length of pipe, fit 'em
together and put a T handle or brace-and-bit on the drive end.
One or two supports to keep the shaft level (you can drill the
first hole with a standard setup, the shaft will rest in that hole
and you will want to level it carefully before doing the second).

After each punch-through, retract the drill and pull out the
wood plug.

It'll take a half day.

Subject

After rereading and hopefully understanding the problem, short of
opening a seam thru that 1-1/2" plywood, as others have suggested, you
can't get there from here.

Unless.....................

You approach this problem like drilling a well, only horizontally
which will require significant cost to built all the componet parts.

Opening up a seam will probably less costly.

Back to basics, why is drilling necessary?

What is the purpose?

Lew

On Thu, 11 Mar 2010 20:31:01 -0800 (PST), allen476
wrote:

On Mar 11, 10:48Â*pm, wrote:
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter

You would want to use an auger bit, but at that length you will be
looking at a custom bit. Not cheap but if you DAGS "custom made auger
bit", you will find some that make them. Why does your hole have to be
that big?

Allen
Have to pull 4 #12 BX cables through it

Above the edge of each joist, drill (4) 1/2" holes centered over
the joist and approximately 4" OC parallel to the joist and 2" OC
across (spanning) it. Insert a saber saw with 1-3/4"
long blade through the hole and cut across the joist and alongside
it, connecting the holes. Pry the 1-1/2" plywood out of the hole
and set aside. This will expose approximately 4" of the joist.
Using a longer blade in the saber saw, cut a 1-1/2" to 1-3/4" wide
slot in the joist, breaking the piece out. This will leave you
with a rectangular cut in the joist adequate for your 1-1/2" pipe
or conduit.

Glue and screw the removed plywood flooring back over the joist
after you've run the pipe, leveling it with floor patching
compound.

--
Nonny
When we talk to God, we're praying,
but when God talks to us,
we're schizophrenic.
What's the deal?

On Thu, 11 Mar 2010 21:15:07 -0800, Larry Jaques
wrote:

On Thu, 11 Mar 2010 22:48:43 -0500, the infamous
scrawled the following:

On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What does the decking have to do with drilling joists? You don't want
to pull it?

It is gled and screwed to the joists so it can not be removed without
destroying both.


What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.

Use a 12ga extension. HF has 25' x 12ga for $10 which are nice. I use
mine all the time for their 12" SCMS. YOu don't mean 12' metal
extension, do you?!?

Yes TWE:LVE FEET.

I did it this afternoon. bought a 12 inch 7/15 AF extension and cut
it in half. Banged the cut end of each peice into a 1.4 to 3/8 NPT
bushing and mig welded it in. Put that bushing into a 1/2 to 3/8NPT
reducer and threaded it onto each end of a 4 ft piece of 1/2"
galvanized water pipe. Chucked a 1 1/2" forstner bit into the hex bit
holder end, and chucked the other end into a 450RPM half inch drill.
When I got in 4 feet, I took off the drive end with s pipe wrench and
using a pipe couipling, added another 4 feet, and so on untill I was
in all the way.


I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?
Augers self-feed and don't break out as hard. There are short auger
sets available if you like 'em.


Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Oh, you do mean physical, not electrical. Why don't you just unscrew
the decking and have a friend help lift it? Or did some jerk just
nail it in? grrr Ooh, flooring might be glued, too, huh? Skilsaw,
cut a long slot, lift it, replace and reglue with caulk as an
adhesive. Cost: 1 sheet of flooring. Time saved: a day. Frustration
saved: Humongous amounts.


Did you read ONE AND A HALF INCH THICK PLYWOOD????

Doing it with the water pipe took almost half an hour for the first
hole, and 10 minutes for the second one. Making the tool took 1/2 hour
at the "borg" getting parts, and half an hour at the fabricating shop
cutting and welding.

Forgot - the hole needs to be 1 1/2 inch diameter

I'd hold my light sabre down there for a couple quick punches through,
one from each side. No extension necessary.

On Thu, 11 Mar 2010 22:08:42 -0800, "LDosser"
wrote:

wrote in message
.. .
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter


Hole saw and angle drill. One joist at a time.

Got a midget to go with the drill? Deck is 16 inches from the floor,
joists are 16 inches high. No access from the sides.

On Fri, 12 Mar 2010 01:43:17 -0500, "J. Clarke"
wrote:

On 3/12/2010 1:08 AM, LDosser wrote:
wrote in message
...
On Thu, 11 Mar 2010 22:46:55 -0500, wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter


Hole saw and angle drill. One joist at a time.

If I understand correctly what he wrote, he doesn't have any access--he
has to drill the first joist and then drill the second one through the
hole in the first, and so on. The difficulty seems to be the 12 feet of
extension--not extension _cord_ but bit extension.


Give the man a medal - HE can read!!!!!

On Thu, 11 Mar 2010 23:04:31 -0800, David Nebenzahl
wrote:

On 3/11/2010 10:06 PM Lew Hodgett spake thus:

wrote:

I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull
cable across to the center of the floor). The joists are sitting
directly on concrete, and the decking is 1 1/2" (you read that
right) plywood.

This is a TOTAL PITA solution, but it will get the job done.

Drill a 1/4" dia pilot thru every 2x8, then it is time for a 1-1/2"
hole saw AND a 1/2" right angle drill.

I wonder if you really read the OP's post. Otherwise, the only way he'd
be able to use your suggestion would be if he could scrunch his body
down to fit in a 7-1/2" high space between a concrete slab and the
decking. Quite a trick, that.

What I don't understand is when he says the joists are "only accessible
from the one side". What does this mean? That the openings between
joists are only accessible from one side of the house? I'm having a hard
time picturing this. And how the hell would he get in there in the first
place--drill a hole from the outside through the rim joist, then each
joist in turn after that?


OK - not in a house. Raised floor in what WAS an auditorium (theatre).
Being made into office space.. The "face" of the platform (raised
seating area) is all that is accessible. Need to get power and data
into the center of that raised floorspace for 6 work-stations.

Make more sense now??

On Fri, 12 Mar 2010 00:29:51 -0800, "LDosser"
wrote:



On re-reading, it appears you are correct and I am wrong. I'd pull the
plywood!
You'd pull 1 1/2 inches of glued and screwed plywood? Destroying both
the plywood and the joists?????..

It took me just over an hour to manufacture the tool and do the job.
With no damage to the structure.

On Fri, 12 Mar 2010 06:35:21 -0800 (PST), allen476
wrote:

On Mar 12, 12:56Â*am, "CW" wrote:
"allen476" wrote in message

...
On Mar 11, 10:48 pm, wrote:



On Thu, 11 Mar 2010 22:46:55 -0500, wrote:
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

Forgot - the hole needs to be 1 1/2 inch diameter

You would want to use an auger bit, but at that length you will be
looking at a custom bit. Not cheap but if you DAGS "custom made auger
bit", you will find some that make them. Why does your hole have to be
that big?

A regular auger bit on extensions should do it. It only goes threw one board
at a time.

But 10' of extensions will be the real PITA. If you don't get the set
screws tight, you'll be ripping up the floor.

Did 6' like that once. Never again.

Allen
I know, I bought a couple of 18" extensions to drill down the wall in
my daughter's townhouse to install wiring for bedroom ceiling lights.
Paid $18 each for the extensinsa, and stripped one on the first hole.
Thanfully the second didn't need as much length.

This time I used 1/2" water pipe, threaded together with pipe
couplings.

On Fri, 12 Mar 2010 09:51:35 -0500, Upscale
wrote:

On Fri, 12 Mar 2010 06:47:26 -0800, Larry Jaques saw and angle drill.
One joist at a time.

So I'll ask you the same question I asked the other fellow who suggested a
hole saw: how the hell is this guy supposed to get into that 7-1/2" high
space to use it? You must think he's some kind of Houdini.

How about a flex shaft driving the bit?
The half inch water pipe was almost too flexible.

On Fri, 12 Mar 2010 07:11:15 -0800 (PST), Sonny
wrote:

A spade bit might have a rough punch-through, so go slow and have
patience at the end point. Make sure the bit is sharp. I think I
would try welding a spade bit onto a 1/2" pipe and make a separate
chuck insert (fitted/welded onto a 1/2" sleeve, for the pipe) for
fitting into the drill chuck. A spade bit is a lot cheaper than an
auger bit for a one-time use (once welded).

If access space, in starting, is limited, also, the 1/2" pipe can be
in successive 24" - 36" sections. Any connecting sleeves will pass
through the 1-1/2" holes and the chuck insert fitting can be moved
back, as each successive pipe section is attached. Save the set-up
for future use (???, LOL) and use the pipe sections for pipe clamps.

Sonny
I tried the spade bit first ( on a test piece, out in the open) and
the breakthrough was BRUTAL. The forstner is self guiding and worked a
real treat.

On Fri, 12 Mar 2010 12:53:21 -0500, "EXT"
wrote:


wrote in message
.. .
I've got myself into a situation -
I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.

What is the lowest power-requiring type of drill to use/ since it
needs to be run on a 12 foot long extension-----.
I tried a speed-bore type spade bit, but it has a bad habit of
"catching" just as it breaks through - putting a severe strain on the
connection between the bit and the extension.

Would a forstner type work better? Or an auger?

Still looking for a viable bit extender setup as well - thinking I
might need to go to 1/2" steel waterpipe with a 7/16 or 1/2" hex shaft
welded into the one end for the chuck to grab. In 3 or 4 foot length
with couplers it should be handleable?

I don't see any drill working, as the shaft diameter is always much smaller
than the drill bit. To drill 6 joists with a 1 1/2" bit means the bit will
drop about 5/8" with each hole as the shaft rests on the previous hole
bottom, 5/8" x 5 joists (I am assuming the first hole will be accurate) = 3
1/8", so you will either have to start real high on the first hole or hit
the concrete with the last hole. I cannot think of any way of getting such a
large hole drilled through so many joists in one go. Can you not go around
the ends and come in from there some how?

Absolutely no way.

And I did it today. Started with the first hole just clear of the
decking - ended up abot 3 inches down from the decking at the other
end.. And I had something like 15 inches of joist to play with.

On Fri, 12 Mar 2010 13:08:28 -0800, "Lew Hodgett"
wrote:

Subject

After rereading and hopefully understanding the problem, short of
opening a seam thru that 1-1/2" plywood, as others have suggested, you
can't get there from here.

Unless.....................

You approach this problem like drilling a well, only horizontally
which will require significant cost to built all the componet parts.

Opening up a seam will probably less costly.

Back to basics, why is drilling necessary?

What is the purpose?

Lew



Ended up using 3 lengths of 1/2 inch pipe @ $7.50 each, 2 of 1/2 inch
pipe couplings @ $1.24 each, 2 of 1/2 to 3/8 reducers @ $1.35 each,
and 2 of 1/2 to 3/8 NPT bushings @ $0.89 each, plus a $16? 12 inch
extension bit (7/16" hex both ends).

Half an hour of labour welding two halves of the extension int the
pipe bushings and the extension was done.

Total cost less than $50.

Rented a 450 RPM drill and a 1 1/2" forstner bit for $14 for a half
day - so total outlay still under $65.
Half an hour to set up and drill the first set of holes and cut an
access hole in the floor where the cables will come out, and just over
10 minutes to drill the second set of holes.

Labour included still under a hundred to get the job done. The boss is
happy.

On Fri, 12 Mar 2010 15:10:36 -0600, Dave Balderstone
wrote:

In article , Larry Jaques
wrote:

Skilsaw, cut a long slot, lift it, replace and reglue with caulk as an
adhesive. Cost: 1 sheet of flooring. Time saved: a day. Frustration
saved: Humongous amounts.

I'm with you on this one, C-less.

He gets through 4 of the 6 joists, and whatever rig he's using snaps
somewhere between #3 and #4, with the bit embedded in #5 becuase he's
hit a knot... Start again.

How many times, and at what cost?

Clare... Don't be stupid. take the easy way.
I did take the easy way.
The dang carpet is worth something like $50 a yard.
The plywood is glued and screwed to the joists. Cannot remove it
without doing significant damage. And remember i it is ONE AND A HALF
INCHES THICK.

I made the tool to do the job and got the job done. Including my time
the cost was just around the hundred bucks (they pay me $35 an hour)

On 3/12/2010 6:05 PM, wrote:
On Fri, 12 Mar 2010 15:10:36 -0600, Dave Balderstone
wrote:

In , Larry Jaques
wrote:

Skilsaw, cut a long slot, lift it, replace and reglue with caulk as an
adhesive. Cost: 1 sheet of flooring. Time saved: a day. Frustration
saved: Humongous amounts.

I'm with you on this one, C-less.

He gets through 4 of the 6 joists, and whatever rig he's using snaps
somewhere between #3 and #4, with the bit embedded in #5 becuase he's
hit a knot... Start again.

How many times, and at what cost?

Clare... Don't be stupid. take the easy way.
I did take the easy way.
The dang carpet is worth something like $50 a yard.
The plywood is glued and screwed to the joists. Cannot remove it
without doing significant damage. And remember i it is ONE AND A HALF
INCHES THICK.

I made the tool to do the job and got the job done. Including my time
the cost was just around the hundred bucks (they pay me $35 an hour)

That's not bad at all--there's a guy who makes 10 foot extensions and
gets something like 100 bucks a shot for them.

On Mar 12, 4:48�pm, wrote:
On Fri, 12 Mar 2010 07:11:15 -0800 (PST), Sonny
wrote:

A spade bit might have a rough punch-through, so go slow and have
patience at the end point. �Make sure the bit is sharp. �I think I
would try welding a spade bit onto a 1/2" pipe and make a separate
chuck insert (fitted/welded onto a 1/2" sleeve, for the pipe) for
fitting into the drill chuck. �A spade bit is a lot cheaper than an
auger bit for a one-time use (once welded).

If access space, in starting, is limited, also, the 1/2" pipe can be
in successive 24" - 36" sections. �Any connecting sleeves will pass
through the 1-1/2" holes and the chuck insert fitting can be moved
back, as each successive pipe section is attached. �Save the set-up
for future use (???, LOL) and use the pipe sections for pipe clamps.

Sonny

�I tried the spade bit first ( on a test piece, out in the open) and
the breakthrough was BRUTAL. The forstner is self guiding and worked a
real treat.

Glad the pipes/extensions worked. That seemed the logical approach.
I didn't think of using a forstner bit and I'll remember the lesson of
that big of spade bit. I've never had to use one that big. And you
still have the pipes for clamps!

Sonny

wrote in message
...
On Fri, 12 Mar 2010 00:29:51 -0800, "LDosser"
wrote:



On re-reading, it appears you are correct and I am wrong. I'd pull the
plywood!
You'd pull 1 1/2 inches of glued and screwed plywood? Destroying both
the plywood and the joists?????..

It took me just over an hour to manufacture the tool and do the job.
With no damage to the structure.


Your Original Post:

[I need to drill through 6 2X8 joists which are accessible only from
the one side. They are spaced 2 feet on centers. (need to pull cable
across to the center of the floor). The joists are sitting directly on
concrete, and the decking is 1 1/2" (you read that right) plywood.]

See anything about plywood Glued to Joists there? See anything about $50/yd
Carpet there?