 The Clarinet BBoard
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Author: Philip Caron
Date: 2025-07-09 02:52
For years the tenon between the two sections of my Bb has been slightly loose at the bottom, leading to some wobble between the sections if left unaddressed. My repair people, two different ones over the years, have corked that tenon so that the cork extends all the way to the bottom, somehow manually thinning the edge of the cork that overlaps the tenon rim so that, once installed, the external cork surface is smooth from edge to edge. The thinned cork edge adds diameter enough to avoid the wobble.
Problem is, no matter how carefully I put those sections together, and how diligently I grease the cork, eventually the thinned edge starts to fray and lose bits of coverage, and that process continues until the cork no longer adds enough diameter, and the wobble resumes. Every couple years I have to get it replaced again.
Is there a more permanent way to fix that tenon?
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Author: Chris P
Date: 2025-07-09 03:07
Attachment: tenoncork2.png (1042k)
Yeah - have the tenon rings rebuilt so they fit much better in the sockets so they're neither binding nor wobbling.
I rebuild the tenon rings so they provide a rock solid fit in the sockets even without the tenon cork fitted. There's loads of different ways to do this - the usual being:
- Machine down the tenon rings, rebuild them with superglue and wood dust, then machine them down to size and recut the slot.
- Machine down the tenon, sleeve it with wood, ebonite, plastic or metal, then machine it down to size and recut the slot.
Tenons with metal tenon rings can either be removed and replaced with new ones fabricated, fitted and machined down to fit the socket, or the end of the tenon could be machined down and fitted with a solid metal ring that's machined down to fit the socket.
Or if you're daring enough, metal tenon rings can be shimmed by first skimming down the existing tenon ring by just enough to make it smooth and even (without going through it), cutting a strip of thin brass or nickel silver sheet to form a ring (which holds itself in place or wired onto the tenon ring), then carefully soft soldering it on and machining down to size.
And make the tenon ring at the shoulder longer so it has more purchase in the socket compared to short ones. Many makers lave that tenon ring too short and some machine it off completely (eg. 1960s B&H clarinets).
No amount of cork will cure a wobbly tenon - the stability is down to the fit of the tenon rings in the socket.
I'm pretty sure I've talked at length about tenon fit in the past on here and elsewhere as it's an ongoing issue. You want the fit to be as good as tuning slides, flute headjoints and sax crooks in their sockets.
Former oboe finisher
Howarth of London
1998 - 2010
Independent Woodwind Repair Specialist
Oboes, Clarinets and Saxes
NOT A MEMBER OF N.A.M.I.R.
The opinions I express are my own.
Post Edited (2025-07-10 02:03)
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Author: clarnibass
Date: 2025-07-09 09:25
I suggest the same as Chris, to build the tenon to a better fit, and I'd use the same methods he suggested.
One thing though, it might depend on local climate, but I don't fit the tenons to be very tight without cork like Chris described in the last paragraph. If I did this here then it would very quickly bind once the clarinet is played. Maybe this kind of fit works better in more humid areas, but here it could even be fit looser than that and still bind when played, so you have to take conditions and climate into account.
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Author: Philip Caron
Date: 2025-07-10 00:06
Thanks Chris P and clarnibass.
I worked for decades in factories full of special purposed machines, yet I never operated one in the sense of doing a job with it, I only ran the grinding machines we made in order to test the software in them that I helped write. The idea of measuring and setting up and machining and rebuilding and re-machining a tenon to fit sounds impossibly daunting to one lacking equipment, training, experience and temperament, but it also sounds like the kind of job any of many machinists I've known would take in stride. I highly admired those people; some were true wizards.
When I first visited my current repair tech, he described a rebuild option, which maybe I didn't pay close attention to, but the modified cork fix I'd previously been using was ok with him too. Maybe my wobble is moderate enough to allow the lesser fix, though of course I periodically need to have it redone. I'll do some math and decide what to tell him next time around.
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Author: JTJC
Date: 2025-07-10 17:12
How did the tenon get like that?
Long ago, I didn't pay much attention to fitting tenons together. That is until it was pointed out to me that care was needed. I think i just used to do it casually, perhaps rolling the joint around until it found it's position. This was especially the case during quick changes of clarinet in the orchestra. Of course, the result was tenons with badly rounded corners. I take more care these days and try to maintain the crisp, factory edge on the tenons. Of course, the corners can't be kept 100% like that, but at least I haven't ruined any more clarinets.
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Author: Chris P
Date: 2025-07-10 21:52
Probably always been like that, or a previous repairer was a bit cack-handed when they removed the old tenon cork and gouged up the tenon rings and sanded their handiwork smooth, or was a bit over zealous with the sanding down of the new tenon cork and took the tenon rings down along too. I see that all the flipping time here and hardly any repairers I've seen tend to address wobbly tenons - only bunging on extra cork in a bid to make them fit.
And if that never happened, it was most likely like that from the factory as many clarinet tenons aren't even a good fit from the word go, eg. many Buffet Prestige tenons, although they have sort of improved things recently in that department.
Wobbly tenons also cause far more damage to sockets than tight fitting tenons as they can rock in the socket which can in turn crack sockets from the inside because of the force applied to one spot against the socket wall - especially the lower joint socket as there's a tonehole immediately below it and that's right inline where the lower tenon ring will apply force to the inside of the socket. Socket rings only reinforce the end of the socket and not anything below it, so socket cracks can still happen and spread from below the socket ring even if the socket ring is well fitted.
Former oboe finisher
Howarth of London
1998 - 2010
Independent Woodwind Repair Specialist
Oboes, Clarinets and Saxes
NOT A MEMBER OF N.A.M.I.R.
The opinions I express are my own.
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Author: Philip Caron
Date: 2025-07-11 05:47
I probably caused the tenon issue, many years ago during my first "incarnation" as a clarinetist. That would have been during high school and for a couple years afterward. The cork had worn enough that the joint was a little unstable, and I used a lot of unnecessary force in fingering. Just playing under those conditions no doubt gradually rounded the tenon. Back then, the idea of physical weak points was one I tended to underappreciate, and the joint wobbling didn't concern me much.
Then, after a little break of 33 years or so and having to start all over, I realized the wobble was an issue that would worsen. I visited a local repair person who replaced the worn cork with a new one, modified as described above. That was in 2007. Wow, I've been practicing on my own for 18+ years.
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Author: clarnibass
Date: 2025-07-11 08:42
>> Of course, the result was tenons with badly rounded corners. <<
This is not that rare but usually on clarinets that are at least several decades old. I mean very significantly round, even tapered throughout the length of the shoulder.
>> The idea of measuring and setting up and machining and rebuilding and re-machining a tenon to fit sounds impossibly daunting to one lacking equipment, training, experience and temperament, but it also sounds like the kind of job any of many machinists I've known would take in stride. <<
In the world of machining for woodwind instrument repair, let alone the machining world as a whole, it's a relatively simple job.
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