Mouthpiece tip repair using CA glue and micro-abrasive glass

[windydankoff]

My headphone cable wound around my clarinet and brought the wrong end crashing to the floor. I broke the tip of a vintage hard rubber mouthpiece that is one of my favorites. I dried my tears, then fixed it in about 1/2 hour. Next day, as proof of my faith (in super-glue), I used it in recording a Sabbath video. It worked fine.

On a great MP, the facing is sacred. Here is a method to restore the facing without altering it - not even by a fraction of a hair. I also use this method to restore old MPs with chips and dents in the facing, and to do re-facing.

Epoxy or CA (super-glue) generally work fine for joining breaks. I used Starbond rubberized CA glue because it bonds incredibly well to hard rubber, but doesn't get brittle-hard. It can be trimmed with a blade or by abrasive. I had two gaps to fill in this piece. They required several applications because CA shrinks as it hardens. If gaps had been larger, I would have used epoxy putty instead (J-B Weld or J-B Kwik). Photos show the damage, the initial bonding, gap filling, and the restoration of the facing.

Excess filler must be finished to conform exactly to the original facing. There must be NO removal of original material. The usual method, using abrasive paper on a flat surface, makes it impossible to see exactly where you are cutting. I found a way to SEE exactly where I'm cutting, by using frosted glass as a transparent abrasive. It's much safer and easier.

I have a piece of translucent frosted (etched) glass that is commonly used for bathroom shelves. It feels like about 800 grit abrasive. It's not as sharp as a true abrasive. It removes material gently, and leaves a smooth finish. By using glass grit-side down and wet, I can see exactly the location and progress of the cut.

I got the idea to use glass to survey the facing surface from a Ridenour YT video. I would use plain glass and fog it with my breath, and see exactly how the facing rolls on the flat surface. I changed to frosted glass because it holds the film of moisture longer. THEN I discovered that it is a perfect abrasive. I can inspect and grind simultaneously!

Photos show the stages of the process - the original break, the initial bond, the filled gaps, then use of the abrasive glass to restore the damaged tip and side rail. It's ... like ... miraculous!

[windydankoff]

continuing ... frosted glass abrasive revealing slight remains of a high spot of filler material, then finally showing the restored surface. I am whole and happy once again!

[LarryS]

Very interesting!

[modernicus]

Very nice work, thanks for sharing all your tips here.
I've several times run across the section of Brad Behn's website where he shows a bit of his process for mouthpiece repair:
https://www.clarinetmouthpiece.com/repairs-restorations-mouthpiece
I haven't broken a mouthpiece myself...yet.  I'm sure it'll happen someday.  What I do have is a pile of broken ones from old caseless clarinets that were probably standing on display and knocked over, or dropped, breaking the beak.  Most are wood.  I wonder if there would be a way to repair them without a donor
piece that wouldn't be too ridiculous?

[DaveLeBlanc]

Beautiful. Would you believe that I actually THREW AWAY a broken mouthpiece about a decade ago because I deemed it "irreparable." It was the original mouthpiece (far as I could tell) to an ultra-rare Bottali plateau metal clarinet.
I was a dumb kid.

[windydankoff]

The last photo shows a little too much water on the glass, implying that a long section of the tip is flat. It is not. I had forgotten that I sometimes use light lubricating oil on the glass. It gives a more consistent viewing result, because it isn't constantly evaporating.

[Windsong]

Bravo.  I am impressed with the technique you have developed.  Ingenious and resourceful.  Ironically, I watched a Youtube video earlier, where a technician repaired an ivory guitar saddle with bone dust and CA, and also demonstrated the strength of baking soda and CA, equating it characteristically to glass, with good shaping capabilities.

[windydankoff]

Powder with typical CA glue forms a solid that is much harder than hard rubber, and sets up instantly. For this purpose, epoxy putty like J-B Weld or J-B Kwik is probably the best choice all-around. No fumes, not even a mild odor. Doesn't shrink. Can be trimmed and sanded before or after it's fully hard. It's a gray-black color. Best way to make it fully black is to mix in fine carbon-black (soot).

[kewald]

Gonna have to find a piece of frosted glass.  Great technique!

[Airflyte]

Gonna have to find a piece of frosted glass.  Great technique!

Hi Ken,

 A Tempered Glass Foot File / Pedicure Rasp is what ordered from a very popular online retailer. Good quality with a fine grit side and a rougher side.

Suitable for conditioning reeds and filing things that need a perfectly flat surface.

http://www.montbleu.eu/crystal-glass-nail-files/Plain_glass_nail_files/Foot_glass_nail_files/BSF_mix/

[windydankoff]

Good for other flattening requirements, but don't confuse it with what I used, which feels like maybe 1000-grit abrasive. I wouldn't use anything more coarse for a MP touchup.

[kewald]

While they don't provide the visibility of glass that Windy uses, When reworking the table and facing of mouthpieces, I use DMT diamond honing plates which I've had for woodworking for many years.  Very flat, and do not wear out.  I have four grits on two plates: Extra Coarse (60 micron/220 mesh), Coarse (45 micron/325 mesh), Fine (25 micron/600 mesh) and Extra Fine (9 micron/122 mesh). 


If a mouthpiece table/facing's initial measurement shows any waviness, I'll run it over every grit, cleaning between grits.  My purpose isn't to change the facing, but rather smooth it out to minimize waviness and also to make the rails co-planar to one another.  Sometimes the process ends up reshaping the facing and changing the tip opening.  Out of about 15 mouthpieces that I've acquired with vintage clarinets, only one didn't need work.  Many wouldn't play at all (at least for me), and all improved in playability.  Now, that doesn't mean much as I know very little about the physics of a mouthpiece - only that when I'm done I like the way they play.

[polemonium]

Neat. If you ever need a piece of fine frosted (ground) glass, it is easy to grind it yourself. I have done this to make a replacement ground glass for a camera.  You just need two flat pieces of glass (even picture frame or window glass), and some abrasive of the desired grade. I used 600 grit silicon carbide from a local tool shop that supplies jewelry makers, rock hounds / polishers, etc; you can also buy grit online.  A pound of SiC grit cost $8 and is a lifetime supply. You mix a little bit of grit with water between the two pieces of glass, and grind them against each other patiently - there are videos demonstrating it.

[windydankoff]

That's great information, to take it to a more precise, or more defined level. Thanks!