Now I open the air hole at the stem end using a 1/16 inch bit mounted in a Dremel tool. Simply use the bit to fan out the opening. This is not as easy as it sounds and takes some practice to get a straight opening. Second picture shows stem after being opened with drill bit. Another option is to use a circular saw type bit to cut a slit in the end of the stem (picture 3).
I now use various small files to clean up and do a little more shaping inside the air hole.
Polishing the inside of the stem is next. I coat a pipe cleaner with brown buffing compound, then chuck it into my drill press and spin it at 1800rpm. Then simply feed the stem onto the cleaner. I like to start with the bristle type cleaner and then finish with the big soft pipe cleaners.
Now the shaping begins. I start by giving the stem some taper with the sanding disk.
I use a barrel shaped bit in the Dremel to start some buttons. As seen in picture 2 you can hold the end of the Dremel against the stem as you move it back and forth and this will act as a guide to give you perfectly straight buttons. The bit has a tendency to really grab hold and take off so hold on tight.
Now I do some basic shaping with an oval shaped burr. Take your time when you do this as it's real easy to take off too much.
I finish the rest of the shaping using various files. First I will use the file to flatten the top and bottom of the stem (area closest to the buttons) until I get the thickness I want. Next I round off the sides to make the stem feel more comfortable in the mouth. Finally I work on the buttons. In picture 2 the stem has been shaped and the sanding can begin.