Re: Drilling for conduit

[Lewis Gardner <lgardner@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Bill Stock wrote:
> I'd like to run some 2" flexible conduit from the basement to the second
> floor (possibly attic). I've already got several smaller holes drilled
> through the first and second floors in this wall. I've also got two access
> panels on the 'inside' of this center wall. But a recent wiring experience
> convinced me that I need a better solution.
>
> I've read that a forstener bit with a right angle adapter is the best tool
> for the job. But considering I need to drill about 12", I'm wondering how
> difficult it is to control this beast and keep the hole close to straight. I
> know from my previous adventures that the three stud walls don't line up too
> well. I was hoping that there is some sort of guide that I could mount
> between the studs to keep the hole straight.
>
> Any insights appreciated.

For rough in work I prefer Milwaukee Selfeed bits like these:

www.mytoolstore.com/milwauke/accself.html

However for what you are trying to do they might not be the best choice.
First problem is cost. You only need to drill a couple of holes and $35
is fairly expensive. Second you are likely to hit some nails. In rough
in work you can see the likely nail locations and avoid them. A selfeed
will mangle it's way past a nail but you will need a stout drill motor
to do that. Third is the stout drill requirement, you will not be able
to drive a 2 9/16" selfeed with a homeowner type drill and right angle
adapter. You will need something like either of these:

www.mytoolstore.com/milwauke/3002-1.html
www.mytoolstore.com/milwauke/1670-1.html

My suggestion would be to use a bi-metal hole saw. Starrett makes the
best I have ever used:

www.mytoolstore.com/starrett/hole001.html

I also like the A2 arbor:

www.mytoolstore.com/starrett/arbors.html#A2

The advantages for your application are:

1. You can dill a pilot hole first with a 1/4" bit and see where it goes
then follow that hole with the hole saw. If you really want to be sure
you don't wander replace the arbor's pilot bit with a piece of 1/4" rod.

2. A bi-metal blade will cut through nails, gently.

3. Since you are not removing as much material a smaller drill motor can
be used.

It will be a slower process with the hole saw than with a selfeed but
you don't have that many holes...

If you are drilling through 12" of wood you will need some extensions
either way you go. Hopefully you have a 1/2" drill so you can use 7/16"
standard extensions. Here is a 12" but they come in various lengths:

www.mytoolstore.com/ideal/ide14-02.html

With a hole saw you will have to stop every inch or so and remove the
plug of wood from the hole (or saw). A stout screwdriver is good for
that task.


Good luck!



I have no connection to mytoolstore.com and I have never used them.
Their site came up quick on Google and their URLs were short...