 The Clarinet BBoard
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Author: kdk
Date: 2022-09-03 21:04
Experienced repairer friends,
Is there a way to definitively test the quality of the seal between the mouthpiece tenon and the barrel socket?
Karl
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Author: Paul Aviles
Date: 2022-09-03 21:40
I don't see why you can't just do a positive/negative pressure test with just the mouthpiece on the barrel. I can block the mouthpiece opening with the fleshy part of palm just under the fingers and apply the lips to the bottom of the barrel. Test this seal with the mouthpiece alone first!
............Paul Aviles
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Author: kdk
Date: 2022-09-03 22:00
I'm hoping for something more sensitive than that. That's about the equivalent of testing pad seal by blocking the open tone holes with fingers and one end of the section with your palm (or thigh) and sucking from the other. It works, but the vacuum measurement isn't as precise as a Magnahelic with rubber stoppers in each opening.
Karl
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Author: jdbassplayer
Date: 2022-09-03 22:30
Paul is right on the money. You can get very precise with the vacuum test when pads are taken out of the equation. Just count the number of seconds the mouthpiece/barrel combo holds a vacuum. If it is more than 10 seconds then you are fine.
If you are looking to get more precise than that I would say just replace the cork for your own piece of mind. No reason to go crazy with super accurate measurements when cork is $12 a sheet.
-JDbassplayer
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Author: stevesklar
Date: 2022-09-03 23:07
Pads can have porosity (and leaks) thus the reason for the magnehelic.
A mouthpiece and barrel have no pads (with a few exceptions like a Marchi).
A simple vacuum or pressure using your mouth test should tell you all you need to know (use thicker plastic wrap to help with the mouthpiece window opening if you are having problems). if you want, use a rubber stopper on the lower barrel open end.
If you want to see if the mouthpiece tenon has any gaps you'll have to check the length of the tenon and compare to the depth of the socket (also width and how nicely it fits in the socket before cork). You can also use a probe to see how much space between the two exists.
As you add more sensitivity, the question about your budget and experience of equipment and techniques comes into play. As you mention, you could use a Magnehelic - large rubber stopper w/Mag hose in the barrel, and plastic wrap closing out the mpc window.
For the inexperienced installing a cork, the important factor can be checked visually. Is the cork a smooth transition where it is wrapped. If there is a large bulge there then that can be an issue. Is there no rocking of the mouthpiece in the barrel, etc. Is it a loose fit, or tight, or too tight and requires a lot of cork grease.
We may ask for what purpose you are asking this question to assist more.
The brand and make of mouthpiece (some cheap mouthpieces may not have a nicely round socket) and brand, condition etc of barrel; tightness of fit, etc.
==========
Stephen Sklar
My YouTube Channel of Clarinet Information
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Author: kdk
Date: 2022-09-03 23:33
stevesklar wrote:
> As you add more sensitivity, the question about your budget and
> experience of equipment and techniques comes into play.
This isn't something I'd try at home - a mouth test is all I'm equipped to do at home. I'm not curious enough to buy sophisticated equipment for this one use.
> As you
> mention, you could use a Magnehelic - large rubber stopper
> w/Mag hose in the barrel, and plastic wrap closing out the mpc
> window.
Plastic wrap closing the window is an idea I hadn't thought of. I think that would seal the window more reliably than any part of hand could.
> We may ask for what purpose you are asking this question to
> assist more.
I am deliberately avoiding explaining the purpose of my question. But thank you very much for the plastic wrap suggestion.
Karl
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Author: Paul Aviles
Date: 2022-09-04 00:15
Yup, sideways works great. Never thought of that one.
..............Paul Aviles
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Author: Dan Shusta
Date: 2022-09-04 04:22
kdk, interesting inquiry...
Firstly, my disclaimer: I am not an experienced repairer.
Now, concerning any possible air leakage between the mpc tenon and barrel socket, may I suggest the following (and I feel pretty sure I'm not the first person to recommend this): Why not just place a very thin to thin, soft, "O" ring with an outside circumference diameter equal to the barrel socket inner diameter?
This way, when the mpc is pushed into the barrel socket, any microscopic irregularities in the barrel top inner surface and the mpc bottom tenon surface will be corrected by the soft rubber.
If you can't push the mpc tenon all the way in, simply insert a slightly thinner "O" ring.
I can't see how any air could possible leak past the "O" ring.
I don't know...maybe this idea is just too simplistic...
However, it just might work.
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Author: kdk
Date: 2022-09-04 04:45
Dan Shusta wrote:
> Why
> not just place a very thin to thin, soft, "O" ring with an
> outside circumference diameter equal to the barrel socket inner
> diameter?
>
> This way, when the mpc is pushed into the barrel socket, any
> microscopic irregularities in the barrel top inner surface and
> the mpc bottom tenon surface will be corrected by the soft
> rubber.
Great suggestion - if O rings are available in enough different sizes to find one that fits that closely.
Thanks,
Karl
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Author: Chris P
Date: 2022-09-04 10:32
If you can see your mouthpiece tenon cork is in good condition, is well greased and the fit in the barrel socket is good, then why are you even needing to prove it's sealing when you already know it is?
You're overthinking things far too much and I'm sure there are loads of other things you should be concerning yourself with instead of this complete non-issue.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: kdk
Date: 2022-09-04 17:28
Chris P wrote:
> You're overthinking things far too much and I'm sure there are
> loads of other things you should be concerning yourself with
> instead of this complete non-issue.
>
I'm very grateful for the couple of constructive suggestions that have been made. Respectfully, I did not ask for comment on the importance of the issue. As I've already said once, I specifically, deliberately, did not address why I asked the question and I will not despite being goaded a little by posts like this one.
I've been posting for many years -decades - on this BBoard and I think I've established at least a minimal level of competence where things clarinet are concerned. This question of mouthpiece tenon seal may in fact be a trivial one even in the situation I have at hand. But that's not at all what I asked about. I only asked a technical question about how to do something, not if it needed to be done.
And, whether or not I have loads of other things with which I should be concerning myself is, frankly, irrelevant (and given my history here, a little insulting). Whether or not this is a non-issue in a context I have not shared is a non-issue as far as my question is concerned.
Karl
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Author: Ed
Date: 2022-09-04 21:10
There have been a few times over the years where I have started to feel that my tone seemed a little diffuse or was missing some resonance and I found that the problem was the seal of the mouthpiece cork. I generally would do a short term fix with teflon tape where I was able to compare with the exact same set up and reed within a few seconds.
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Author: stevesklar
Date: 2022-09-04 22:41
thickness is 1.03 Millimeters
stated on the page to the right at "Item Thickness"
> May I suggest to you and others to try and use "real cork" tape? It's retally
> available at Amazon. In the ad below, the thickness isn't mentioned so I'll need to
> do some more research. It's appearance makes it look quite thin and you would
> be able to use your cork grease in your normal manner.
> https://www.amazon.com/Duck-1-88-Inch-5-Yard-Single-
> 284879/dp/B00T59NFRM/ref=sr_1_2?
> keywords=cork+tape&qid=1662276313&sr=8-2
> Just a thought...
==========
Stephen Sklar
My YouTube Channel of Clarinet Information
Post Edited (2022-09-04 22:42)
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Author: Dan Shusta
Date: 2022-09-04 23:22
Thanks, stevesklar, for finding and revealing the thickness of the cork tape.
Interesting...I have just looked, again, numerous times trying to find "Item Thickness" and the ad on my computer doesn't show that. Under "About This Item" is listed Brand, Color, Material, Number of items, and Size.
I looked again several time on the right side of the page and still couldn't find it.
I just don't understand why I'm not seeing it.
Anyway, as I looked at the questions and answers, I was curious as to the tape's effectiveness at "sticking". The answer about this stated that if you press it gently against a wall, it can be repositioned. However, if you press "hard", if you try to remove it, in doing so "it will peel the paint off of the wall". I liked that answer.
IMO, this Duck Brand "Real Cork Tape" may be a better substitute than Teflon tape.
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Author: stevesklar
Date: 2022-09-04 23:34
I'd be hesitant in using that cork tape though.
It appears to be "chunky cork" or left-over pieces that are glued and compressed together to create a product. In looking at the examples they give for the cork tape none of it is taking a compression or any potential tearing motions.
it's uses is defined as "Ideal for décor"
But it may be good enough for some quick test.
==========
Stephen Sklar
My YouTube Channel of Clarinet Information
Post Edited (2022-09-04 23:34)
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Author: kdk
Date: 2022-09-05 00:51
stevesklar wrote:
> I'd be hesitant in using that cork tape though.
>
> it's uses is defined as "Ideal for décor"
> But it may be good enough for some quick test.
>
I'm not sure it would be good for a quick test. Sounds like it either can move around if applied with light pressure or stays put more or less permanently (or at least as permanently as contact cement) with firm pressure. Not much good for a quick test if it moves or if you can't get it off afterward.
But it does sound like a possible candidate for a medium-term first-aid fix if a cork comes loose or tears. Teflon tape slides around and bunches up - the cork tape might be a more reliable fix until you can get the cork replaced.
Karl
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Author: Micke Isotalo ★2017
Date: 2022-09-05 12:33
Not an answer to the OP, but when I test a mouthpiece-barrel seal I simply put the mouthpiece inside my mouth deep enough to cover the whole window, seal my lips around it the same way as when playing, press the open barrel end against my palm - and then blow as hard as I can. Thus just a simple positive pressure test, with no plastic wrap, rubber plugs, or flute-like sideways blowing involved (and I don't think my mouth is any bigger than on other adults ).
I understand the reason for a negative pressure test (suction or vacuum) on the joints, and especially the lower joint where the low g#-pad kept closed only by its spring tends to open at pressure - but what's the advantage of a suction test of a mouthpiece-barrel seal, over a positive pressure test?
By the way, on an upper joint and by just blowing in at one end and closing the other with my palm, I've never been able to "blow open" any key that is kept closed just by spring force (not even on a bass clarinet). If there has been a leak, it has always been a pad in need of replacement.
Personally I would never rely only on a suction test of the joints, since at least to me, a pad holding vacuum perfectly may not do so for the opposite (for instance if a key spring isn't strong enough). After all, when playing we do not suck in air but we are blowing (as also Morrie Backun commented on one of his videos). Nevertheless, I do not deny that a combination of both methods could be useful, at least to some extent and especially on the lower joint.
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Author: donald
Date: 2022-09-05 15:32
The actual amount of air we blow into the clarinet when playing is very little once diffused in the bore. To demonstrate this, play middle C with just the mouthpiece/barrel/upper joint and then experiment with putting your finger over the end of the joint. The pitch will be affected as your finger will interfere with the pressure wave, but you can feel very little actual air-flow. People on this board (and Borry Mackoon) constantly perpetuate the myth that we are blowing a significant flow of air through the clarinet (though, it is useful to imagine you ARE doing so when playing).
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Author: stevesklar
Date: 2022-09-05 16:57
The upper joint throat Ab key
and the lower joint pinky Eb/G# key
are two keys where spring tension can get a tad soft over time.
When this happens, just with blowing pressure they can open while playing.
Of course, a pianissimo may not do this and require more pressure such as double fortissimo. So one may dismiss bore pressure, but it can be significant enough.
==========
Stephen Sklar
My YouTube Channel of Clarinet Information
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Author: Arnoldstang
Date: 2022-09-05 19:42
Water! Dip the cork end of the mouthpiece in water or just coat the cork. Put the mouthpiece on the barrel leaving 1-2 mm of space/gap. Close off the open part of the mouthpiece with your hand and blow strongly from
the barrel joint end. See if there are any bubbles. I used a mirror to see the gap area. There were no bubbles with my equipment.
Freelance woodwind performer
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Author: kdk
Date: 2022-09-05 20:20
Arnoldstang wrote:
> Water! Dip the cork end of the mouthpiece in water or just
> coat the cork. Put the mouthpiece on the barrel leaving 1-2 mm
> of space/gap. Close off the open part of the mouthpiece with
> your hand and blow strongly from
> the barrel joint end. See if there are any bubbles. I used a
> mirror to see the gap area. There were no bubbles with my
> equipment.
>
Good suggestion. Same principle as putting a tire in water and looking for bubbles to find a hard-to-find slow leak.
Thanks,
Karl
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Author: Fuzzy
Date: 2022-09-05 20:43
Donald,
I appreciate your post. I know the topic has often been touched on before - and the image of blowing an air stream through the instrument might help in some contexts for some people...but I found your wording and example to be thought-provoking.
The amount of air fitting between the reed and the mouthpiece (in total measure) couldn't be much more than what we could blow through a small drinking straw, could it? (Regardless of how hard we blow.)
At any rate - it can't amount to much measured volume.
I would think this to be true for most/all wind instruments - otherwise, how could a bass saxophone be played by a human? It must be the vibrating air column produced by the reed, right? (And not the air being "blown through" the instrument).
I don't want to derail this thread, but did want to thank you for the post - I think it addressed (what can be) a difficult topic and made it very easy to understand.
Thanks,
Fuzzy
;^)>>>
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Author: Paul Aviles
Date: 2022-09-05 23:48
Fuzzy is right about the air. I've posted this before and someone has already tried this on clarinet........no air needed to play wind instrument.
https://www.youtube.com/watch?v=WZvDvuxjHvU
The VIBRATION of the reed is merely an actuator for the air column already present in the horn. Of course the imagery we perpetuate does help get us to where we need to be in terms of the feel and effort to get the proper actuator going. But, no air necessary.
.............Paul Aviles
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Author: stevesklar
Date: 2022-09-06 00:26
yup. no air needed.
But many clarinet players tend use their air column to stimulate the reed. This air column tends to enter the clarinet itself and add another complexity that could cause issues. One could add a diaphragm to stimulate the clarinet bore itself and an air redirector to their clarinet to make everything easier.
==========
Stephen Sklar
My YouTube Channel of Clarinet Information
Post Edited (2022-09-06 00:29)
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Author: Dan Shusta
Date: 2022-09-06 01:14
Hey Karl,
Here's my way to definitively test the quality of the seal between the mouthpiece tenon and the barrel socket.
Using a modified version of Micke Isotalo's testing method, I inserted just "one" ring of my Prescott mpc into my barrel. Then I used Gordon (NZ)'s method of blowing wherein my cheeks are slightly bellowed out while blowing. While using both of these methods, I detected "zero leakage" from the single 0-ring. I figured if this method gave me "zero leakage", adding the two remaining O-rings would only certify "zero leakage" for my purposes.
As to the Riffault cork tenon mpc, I inserted just 1/3 of the cork section into the barrel. I did the same testing procedure as with the Prescott mpc. I, again, came up with "zero leakage". I figured, again, that pushing in the remainder of the cork would only certify that "zero leakage" would be the result for my purposes.
To sum it all up succinctly, if a small portion of the tenon material gives a person "zero leakage", inserting the remainder of the tenon material will just assure the continuance of "zero leakage".
I thought this was a neat, little experiment.
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Author: kdk
Date: 2022-09-06 02:28
Dan Shusta wrote:
> To sum it all up succinctly, if a small portion of the tenon
> material gives a person "zero leakage", inserting the remainder
> of the tenon material will just assure the continuance of "zero
> leakage".
Or, if any part of the tenon seals, all of it seals.
Karl
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Author: Steven Ocone
Date: 2022-09-06 17:16
Be aware that sockets are frequently not cylindrical (they can have a smaller diameter at the very end or visa versa). Also if you have o-rings instead of cork, check to see that they aren't abraded or have any small tears (I don't expect they would but I have run into this problem in other applications).
Steve Ocone
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Author: Micke Isotalo ★2017
Date: 2022-09-07 22:19
A truly fascinating experiment, the one linked to by Paul.
However, I hope it doesn't fool anyone to wrong conclusions - such as:
- "No matter if I use my diaphragm/abdominal muscles for breath support or not, since how I sound is not about how I blow into the instrument, but just about the vibrating air column inside the bore."
Or:
- "No matter if my clarinet is sealing well or is leaky like a sieve, since how it sounds and behaves is not about the air going in it and out, but just about the vibrating air column inside the bore."
All of us who have had even a tiny leak from a pad (and the actual airflow through it would probably be ridiculously small in quantity, if even measurable) can testify to its immense effect on the response of the instrument (on the tones below the leak, and the more the higher up it's located).
Let us also remember that even in that experiment, a continuous airflow is still needed - though it's diverted away from the bore and affecting the latter only through an airtight membrane. Block that airflow, and gone would be also the sound from the instrument.
Post Edited (2022-09-07 23:12)
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Author: clarnibass
Date: 2022-09-08 10:05
As mentioned in several replies above, you can easily test by plugging it with your hand, but you can also use tape, etc.
More accurate than suction is blowing, but don't just blow normally, you sort of "squirt" air from your throat. This is very sensitive in identifying leaks, and I have a magnehelic machine for comparison. For the part itself it doesn't matter how you do it, only the "strength" of how you blow, but pushing it from the throat this way is a lot more sensitive so you can feel it. The only thing is it takes some experience to get a feel for it, changing and controlling the amount you push. Maybe at first practice on just the barrel and then just the mouthpiece, so you have a comparison.
As someone suggested you can use a "medical" approach of just replacing the cork, assuming this is a regular tenon with a cork. The question is whether you want it to seal or just want to know if it is sealing now.
Here is another option that works great with clarinets in general. Plug one end, fill with water, make sure to not have any overflow and also that the water is at least higher than the area you want to check. Then dump the water, checking that it is not running back on the outside, and then blow into it (with one end plugged). Sometimes you would even see the water running out through the leak before you dump it. When blowing, you will hear air bubbles through water in the location of the leak, and often will see it too. You only need to not have water on the outside because then it's very hard to see where the leak is coming from, but I guess in the case of just a mouthpiece and barrel it's not really important anyway.
You can also just blow while in it's water, which is a little tricky with just your hands and mouth.
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