Philip wrote with some good questions about finishing the tip rail.  I 
have posted some of this before, but here it is all together:

--- Philip  wrote:

 > Hi Paul, I was wondering about the formation of the
 > tip rail on HR mpcs.  
 > When cutting them down it lengthens and I understand
 > (assume) that it has to
 > be trimmed a bit if that occurs.  What I dont know
 > is the formation of the
 > inner tip rail.  

These are MY methods, others may do it differently:

Whether metal or HR, does not matter... the tip rail widens.  If you 
trim the outside, you are back to where you started more or less.  You 
have reduced the tip opening.  That may be your goal... to clean it up.

The common practice is to then file the baffle so that the 
chamber/baffle flows smoothly into the tip, and forms the inside of tip 
rail.  

The file I use is about 1/4" wide in the middle, and tapers to a point.  
It is flat on one side (which is the side I use against the mouthpiece, 
and slighty curved on the other (which I don't use at all).  I have a 
little blue plastic handle that the file is inserted into.

If you lay the mouthpiece flat on its back, the conical shape of the 
body will make the centerline of the mouthpiece angled down.  And the 
tip rail will be even more angled down.  If you will hold your file at a 
contant angle (I do this by holding it, and dragging a knuckle lightly 
on the table) or even resting the end of the file handle on the table or 
sometimes on my glass work surface, a fixed minimum angle is 
established.  I move the file in a circular motion.  The part of the 
file that actually contacts the baffle is about 1/2" - 3/4" from the tip.  

So, I do the inside of the tip rail first, the most shallow angle to the 
tip rail.  Then I work about 1/8"-1/4" back into the mouthpiece, raising 
the back of the file a bit and file another flat, in effect, making 
another angle where the first flat cut into the baffle.  

Then I blend it all together.

Once this is done, the mouthpiece is playable, but not pretty.

I wrap a pc of 600 silicon carbide paper around the file and sand the 
filed area.  If you will observe file angle, keeping the end of the 
handle at the same angle as your first cut, or slightly higher, you can 
never hit the tip rail!

Finally, tear a strip of sil carbide paper about 1/4" wide by 1 1/2" 
long.  Place this in the chamber, and lighly push against it with your 
thumb, holding the body of the mouthpiece in the palm of that hand.  
Pulling the sandpaper out from under, drawing it toward the tip, but at 
an angle slightly greater than the tip rail angle, you can sand the 
baffle without touching the tip rail itself.

Do this, working back and forth across the baffle until you have removed 
file marks.  

Then repeat with a few strokes of 800 paper.  Repeat with a few strokes 
of 1000 paper.

NOW, check this out...

Get a wood dowel 1/4" or 5/16" dia.  Grind or cut a flat for about 1 
1/4" on one end, nearly to half the diameter.  Glue on, with CA or 
contact, a pc of 1/16" cork.  Then on top of that, glue on a pc of 
chamois.  This is your baffle polishing tool.

Dip this in Kit ScratchOut plastic polish.  Kit makes car wax and car 
detailing products, you get this plastic polish at Autozone or other 
auto parts places.

Polish the baffle, again, observing the angle of the tip rail, and do as 
you did with the file and don't get on the tip rail itself.

You can put a nice polish, so good it looks like it was not touched.

This is NOT necessary, but looks good to your customer.  On the other 
hand, it probably helps droplets of moisture to move away from the tip, 
rather than gripping on the rough surface.  Maybe it is better?

For the final touch, again, purely cosmetic, but looks good to your 
customer, polish the table and facing.  Here is a VERY easy way.

Turn your silicon carbide paper over, paper side up, on your glass work 
surface.  Draw the mouthpiece over the paper side just as you did to 
flatten the table, just a few light stokes.  Then repeat with a light 
lift, polishing the side and tip rails, just once or twice.  

There is just enough "dust" from the silicon carbide in the paper to put 
an almost mirror finish on the table and rails.

Finally, again using the Kit ScratchOut, and a soft cloth, by hand, 
polish the outside of the mouthpiece.  Buff to a shine, and then wash 
away any remaining polish in the chamber and bore.  Wipe clean and dry, 
and it will have a nice glow.  THIS looks professional to your customer, 
and is easy to do.  I apply a thin, clear patch to the beak.

 >
 > One other thing...on the runyon mpcs with the very
 > thick rail....It becomes
 > extremely wide when opening up...how does one remedy
 > this...?  remove
 > material from the outside of the piece?

On the Model 22's the side rails are quite wide.  Santy called this the 
"Squeek-proof Facing".  It allowed beginning students to place the reed 
quite crookedly and still work well.

Generally, material is filed from the outside.  You may place an old 
reed on the mouthpiece, and with a scriber, the tip of a sharp pocket 
knife, Xacto blade, etc, mark along the edge of the reed on both sides.  
Then file away excess material.  Of course, you will have to sand out 
file marks, polish the sanded area.  This is done before you do all of 
the polishing work described above.

 >
 > thanks
 > Philip

Any time!

I'll post this on the mouthpiece work group.

Paul