Polishing a Vintage Hard Rubber Mouthpiece

I've seen a lot of posts on various saxophone websites about how to clean up an old oxidized hard rubber mouthpiece.  Hard rubber, if left in the sun or put under hot water, can quickly oxidized and leave a dull finish.  Sometimes leaving a ligature on the piece and leaving it out in daylight can "print" the shape of the ligature on to the mouthpiece.  Just look at "vintage hard rubber mouthpieces" on Ebay and you can see what I mean.

The oxidation is often accompanied by a sulfur smell.  The smell can be removed without cleaning up the mouthpiece, but I'm going to do both.  I know that I can polish for hours with a commercial polish like Simichrome or Flitz to remove the oxidized layer, but that is extremely slow.  It is also possible to start with something like 1500 grit wet/dry sandpaper (using water) and quickly remove the oxidized layer, but that seems too aggressive.  

I decided to try inexpensive fingernail polishing and buffing blocks used by manicurists.  Type in something like "nail polishing block" on Ebay and you will see what I mean.  They tend to have 4 sides with different grades of "sand paper" (it isn't really sand paper, it's way less aggressive).  They are about $1 each and one can do several mouthpieces.

I first tried it just on the beak to see how aggressive the roughest (#1) side was.

I used water here because I was concerned that the little sanding block would load up with ebonite.  Turns out that it works better without water.

You can see there is some brown residue on the block and the mouthpiece.  It seemed to be working.

 I continued to work through the rest of the abrasive levels and finished with #4.  Above is a picture where the polisher was only used in front of the ligature lines, so you can see how bad this mouthpiece was oxidized.  I can't reface a mouthpiece and have it look like that.

 Now I'm getting close.

I couldn't get the block in to the spot right in front of the bulb on the shank.  I'll have to use a string there.  But overall it worked just fine.  I still think that finishing with Simichrome will really get this to shine like new.  And, the sulfur smell is gone.  

After going through all of this with the fingernail polisher, I took out my old bottle of Brasso.  Yes, the bottle says that it is for brass, copper, stainless, aluminum, etc.  All metals.  How does it work on ebonite?  Very, very good.  It contains ammonia (so don't drink it) and a very mild abrasive.  The label says to avoid contact with skin and to wash it off of your hands if you get it on yourself.  That being said, I've never had any reaction to it.  You will see it quickly remove the brown oxidized ebonite, which will stain the polishing clothe (to the point that it can't be washed out).  So use a rag.  And wash off the mouthpiece before using it (quick rinse in cold water and dry it off).  It will not remove scratches, only the brown oxidized layer.

To keep it shiny, and prevent it from oxidizing again, I recommend wax.  There are lots of food grade waxes, like the black wax used on some cheese (although you might get a funky smell again).  I prefer to rub it down with plain old wax paper.  It is definitely food grade, but getting harder to find.

After all of this experimentation, I tried Brasso polishing compound.  It appears to be a mixture of kerosene and clay.  While it isn't anything that you would want to put in your mouth, it sure works.  Just make sure to wipe it clean when you are done polishing.  I've tried washing with cold soapy water after polishing a mouthpiece and even that can make a dull finish reappear.  Now I wipe really good and then use black food grade wax to seal it.