 The Clarinet BBoard
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Author: LJBraaten
Date: 2026-03-24 08:53
I finally broke down and replaced that loose tenon cork; I’ve been putting it off nearly a year! The most labor intensive and easy to botch up part for me is the sanding, getting that even bevel, or barrel shape on the cork. As I was preparing the strip of cork it occurred to me: Why wait to bevel it until after I install it? Why not now when it’s flat and unobstructed? So I did, and it saved a lot of labor. Here se the steps:
1 For a sander I used a standard emery board nail file.
2. I laid the cork strip flat and near the edge of 1” board. This gave me room to angle the file downward without scraping the working surface.
3. Occasionally place the strip in the tenon groove to check the edges for alignment with the tenon. The edges can go a little lower since the contact cement raise the cork a bit.
4. Glue on the cork and do final touch up sanding.
I didn’t think of step three until after I glue the cork down. I had not sanded it enough so my “touch up” involved a lot of sanding. Checking would have made the job easier.
Laurie (he/him)
Post Edited (2026-03-24 08:56)
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Author: clarnibass
Date: 2026-03-24 12:19
I do it somewhat similarly but with a few differences...
First, I prefer to not have a barrel shape to the cork, but just a sort of taper/curve to the edges to a degree. Especially the outer edge, so the socket doesn't collide with it and tries to peel it off. I prefer the overall feel and firmness of a more straight tenon cork as opposed to the "gradual" feel of the barrel shape so to speak.
As far as the steps...
1. Same. I mostly use a flexible nail file with two grits.
2. Pretty much the same. I sand the taper/curve of the edge before gluing the cork. For saxophone neck corks I sometimes sand a slight taper at the back, also before gluing, so the the result is more cylindrical before any sanding and curve/taper the back corner too. Basically I do any sanding that is possible before gluing.
3. I don't sand the edges to be lower than the shoulder. The glue only adds a minuscule insignificant amount to the thickness, nothing that really affects it. Some people use a very thick layer of glue, smeared with a brush, though even that would add only a tiny amount. I only smear a thin layer and there is an invisible difference between the cork and the shoulder heights before and after gluing.
Bonus 0 step: I measure the socket and the tenon to decide on the cork thickness to use, to prevent a lot of sanding and waste by using a thicker cork.
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Author: Chris P
Date: 2026-03-24 15:06
I sand my tenon corks down by spinning the joints in my lathe so they're a nice and even barrel shape. Make sure you have the overlapping end (which you'd trim off and smooth down beforehand) facing upwards so it doesn't get torn in the process.
I use 180 grit abrasive to get the initial shape, then finish with 400 grit if necessary.
Former oboe finisher
Howarth of London
1998 - 2010
Independent Woodwind Repairer
Single and Double Reed 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: LJBraaten
Date: 2026-03-25 06:09
Carnibass , I agree with you on the barrel shape, I only mention it because some here recommend it.
I should have been clearer with my remarks about going below the edge of the groove. I wouldn’t deliberately try to do that or recommend it. I only mention it as a consolation, to not think all is lost if the cork is accidentally sanded too much. I would tend to leave it a little high and touch it up after it’s installed.
On the other step, my measurement is to line up the edge of the cork in the groove to eyeball the height. I was generous this time because it always needs to be higher than I think. Espevially ifor my jinxed middle tenon, where even a slightly too thin cork has resulted in the clarinet coming apart while being played, especially in warmer weather. I’ve replaced lots of tenons in the past 15 years with no issues, but this one has been giving me fits. This is at least my thirff attempt in a few years, but I’m certain I got it snug this time!
Oh for a lathe! I could probably find a few uses for one!
Laurie (he/him)
Post Edited (2026-03-25 06:11)
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Author: clarnibass
Date: 2026-03-25 11:44
>> Make sure you have the overlapping end (which you'd trim off and smooth down beforehand) facing upwards so it doesn't get torn in the process. <<
Or use the reverse direction on the lathe, if it has it. That's what I do in the rare times I sand tenons on the lathe and forget to glue it in the "normal" direction (I prefer to sand them by hand anyway).
>> Espevially ifor my jinxed middle tenon, where even a slightly too thin cork has resulted in the clarinet coming apart while being played <<
The middle tenon is the trickiest because:
- It's usually short with the least support, not just the cork but also the tenon shoulders.
- It has the most force put on it, essentially trying to wobble it while playing.
- As a result of the above it tends to wear much more than the others, increasing those same issues, especially on old and very used clarinets.
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Author: Chris P
Date: 2026-03-25 18:24
I have the tenon on the tailstock end when sanding it down as that's far less dangerous than it being at the chuck end.
If I feel like living dangerously and I glued the tenon cork in the wrong orientation and just can't be arsed to simply lift the safety cover and flip the switch to reverse the motor, then I'd dance with death by sanding it at the chuck end while keeping an eye on the grim reaper stood there watching in the doorway.
Former oboe finisher
Howarth of London
1998 - 2010
Independent Woodwind Repairer
Single and Double Reed 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: clarnibass
Date: 2026-03-26 11:47
>> I have the tenon on the tailstock end when sanding it down as that's far less dangerous than it being at the chuck end. <<
Sanding the cork on the head stock side means either holding the section on the outer shoulder, or using some kind of center which would put pressure inside on both sides, and I wouldn't do either...
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Author: Chris P
Date: 2026-03-26 17:50
I use a wooden centre in the chuck and a live centre in the tailstock to hold the joints between and haven't died yet. The joints are mounted in this way during several manufacturing processes, so it's hardly an issue.
Former oboe finisher
Howarth of London
1998 - 2010
Independent Woodwind Repairer
Single and Double Reed 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: Paul H
Date: 2026-03-27 02:42
related question: How do you cut the cork precisely to the width of the tenon slot? Anyone offer their techniques?
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Author: Chris P
Date: 2026-03-27 04:00
Attachment: tenoncork2.png (1042k)
I measure the width of the tenon slot with Vernier callipers, then transfer that measurement to the sheet cork with the depth gauge end of it using a steel ruler as a cutting guide (placed against the end of the depth gauge and checked at several points to be sure it's parallel), then cut the strip with a sharp scalpel.
Always make the cork strip the exact same width as the tenon slot (or just a hair wider) as you don't want any gaps where cork grease and water can get in and under the tenon cork. Overlapping joints are always best as they ensure an airtight and watertight seal compared to butted joints which can separate and cause leaks.
One odd way I've seen and wasteful at that is someone I knew used to glue the cork strip to the entire tenon and sand away at it, but that doesn't allow the edges of the cork strip to bond to the edges of the slot, plus the risk of sanding the tenon rings is much greater, especially with all wooden tenons.
When I fit the cork strip to the slot (using contact adhesive), I roll the edges of it against the edge of my bench to be sure they're pressed down well to ensure a good bond. Then leave them for a day before sanding down to shape. It's not really necessary to leave them as contact adhesive is workable and forms a good bond once both the glued surfaces make contact and are pressed together, so emergency tenon corks (and sax crook corks) can usually be replaced in around half an hour.
Former oboe finisher
Howarth of London
1998 - 2010
Independent Woodwind Repairer
Single and Double Reed Specialist
Oboes, Clarinets and Saxes
NOT A MEMBER OF N.A.M.I.R.
The opinions I express are my own.
Post Edited (2026-03-27 04:09)
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Author: clarnibass
Date: 2026-03-27 10:26
>> How do you cut the cork precisely to the width of the tenon slot? Anyone offer their techniques? <<
Pretty similar to how Chris described, except the only difference is that after getting the channel width with the calipers, I use the same inside prongs to get the width of the cork. It doesn't really matter, I can just see it better this way rather than with the depth gauge. I eye ball probably about 0.2mm to 0.3mm extra width to make sure there is no gap between the cork and the shoulders, also accounting for the knife thickness itself (it will lose a minuscule amount even when right against the ruler).
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