 The Clarinet BBoard
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Author: Dan
Date: 2002-11-21 14:52
Maybe the following will bring a chuckle or two but it sure saved my day.
Not too long ago, I decided to repad my own trusty Vito. Before repadding, I always pressure check the section to make absolutely sure that it is solidly air tight. I began with the upper section first.
After plugging all of the holes except one with neoprene plugs, I pressurized the section and watched in amazement as the pressure needle slowly descended to zero! I couldn't believe it. I rechecked all the plugs and made sure the tape over the register key hole was secure. While checking it again, I put my thumb over the taped register hole to "make sure" that no air was coming out from it. The pressure needle again slowly descended to zero. I didn't have a leak light and besides, I didn't really think it would help me on this one. I thought for a while and then I visualized a technique I used to use when I was a kid for finding leaks in bicycle inner tubes.
I figured, hey, this is a plastic clarinet, why not do the same thing? So, I filled the bathroom sink with luke warm water, submerged the upper section, pumped in the air and started looking.
Yep, I saw the air bubbles!! Have you figured it out yet???
The air bubbles were coming from AROUND the register tube... in between the tube and the clarinet body.
After thoroughly drying it off, I sealed around the metal tube with epoxy, repressurized it, and the needle stayed solidly at 3oz per sq. in. for a long, long time.
Any other stories someone would like to share?
Dan
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Author: Wes
Date: 2002-11-21 15:15
Yes, the register tube is often suspect for leaks. I recently found a loose one on a new Buffet A clarinet. After sealing, the clarinet played great. The bubble test is very important for checking for leaks in oboes. Good luck.
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Author: David Spiegelthal
Date: 2002-11-21 15:19
Not so unusual --- a few months ago my trusty Kohlert bass clarinet seemed to get more and more resistant, although I couldn't find any leaks with the leak light --- played a concert and had a real tough time, even squeaked once (which I never do any more) --- got the horn home after the concert, took the upper register key off on a whim, and lo and behold the register tube fell out --- it had come loose within its tapered hole and had been shifting up and down unnoticed for some time, creating an intermittent leak right in the worst place (the very top of the instrument) which wasn't detectable with the leak light. Generally these tubes are tapered and are just press-fit into their hole --- clearly they can and do come loose occasionally.
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Author: William
Date: 2002-11-21 15:20
George Jamieson (noted accoustician and co-designer of the famed NX clarinet) once made a surprising statement to me to the effect, "a clarinets playing should not be affected by small leaks." He let me try the proto type NX in his home. It was in a hand made wooden box and lots of extra rods for the lower pad mechanisms, and didn't particularily play that well given my mpc and reed set up. But I what I remember most was that statement of his about leaks. It was made it reference to the NX clarinets accousical properties (which he would not specifically share with me). "Small leaks should not affect a clarinets playing"--amazing statement by a master accoustician, to say the least.
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Author: Bob
Date: 2002-11-21 18:29
Reminds me of the time my Dad and I spent a long day and night replacing our well pump and it wouldn't work after the electrical box was installed. Late night we accidently discovered that one of the insulated wires in the pump electric box was broken inside the intact insulation....a manufacturing defect most certainly. We replaced the wire and went to bed. Oh for those old balloon tire days.....enjoyed your story.
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Author: DougR
Date: 2002-11-21 23:31
My Selmer tenor (super balanced) has had weird stuffiness and gurgles in the lower register, and every repair guy I took it to SWORE the horn was tight. Finally, one of them discovered a pinhole leak in the solder on the neck octave key tube, and fixed it, and the horn is 99.9% improved (there's still a trace of that gurgle/stuffiness, but I'm thinking, there's gotta be another microscopic leak someplace). So, clarinets may or may not play OK with small leaks (see above) but my tenor most certainly does NOT!!
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Author: Karel
Date: 2002-11-22 09:50
What would be a good, safe material to use for sealing around the register tube, i.e. something that can be easily undone? I have used "plumber's tape", but wonder how reliable it is? I am reluctant to submerge my R-13 for a bubble test. Any advice please.
Karel.
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Author: Bob
Date: 2002-11-22 11:30
DAP makes a product called "Fun Tak", a reusable adhesive that you might consider. It's usually use as a replacement for tape and tacks for wall hangings. I use it for lots of stuff...especially good for keeping external drives etc from getting knocked off the desk
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Author: Mark Charette
Date: 2002-11-22 11:51
Karel wrote:
>
> What would be a good, safe material to use for sealing
> around the register tube, i.e. something that can be easily
> undone?
IIRC wax is used for Buffet tubes.
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Author: Karel
Date: 2002-11-22 13:22
Thanks Bob. Mark, I am sorry but I don't know what IIRC wax is or where to get it?? Karel.
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Author: Gordon (NZ)
Date: 2002-11-22 13:57
What is IIRC wax?
Beeswax would probably do. It has a slightly gooey quality.
Shellac is often used, but it is really quite brittle.
BTW leaks sometimes exist around glued-in tone hole insterts for ring keys (on the models that have these inserts), particularly for lower quality manufacturers. On Chinese instruments these leaks can be severe.
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Author: Matt Locker
Date: 2002-11-22 13:58
Additional questions for this great thread:
How does one seal the register tube &/or thumb pipe?
Do you seal on the outside of the instrument or in the bore?
Would bee's wax work for this purpose or is there some other wax that's better?
How about hot glue?
I have a Vito with a leaky thumb pipe so this is definitely of interest. The clarinet plays fine but it's irritating to get a wet thumb after 15 minutes of playing.
Thanks,
Matt
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Author: David Spiegelthal
Date: 2002-11-22 14:17
I would seal the register tube within the body of the clarinet with a thin coating of silicone glue (aka "RTV") around the outside of the register tube. Seals well, adheres just enough but not too much.
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Author: Bob
Date: 2002-11-22 21:26
The silicone sounds like a good idea to me. I now can see that the DAP stuff is probably too "heavy".
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Author: ron b
Date: 2002-11-22 21:33
Karel -
The ideal glue you seek, "...a good, safe material to use for sealing around the register tube, i.e. something that can be easily undone? ", has been around for centuries
When a register tube is so loose it will pop out with moderate pressure (use a wooden dowel) most techs I know heat the tube to apply a thin coating of [stick] shellac and reinsert while the shellac is still quite soft. The tube can be reheated with a resistance device if necessary to insure a total seal. The tube is easily removed by the same method; just reheat it. The shellac may become brittle in extreme low temperature conditions, too cold for serious playing anyway, but probably won't fail unless it's somehow bumped or jarred severely. The nice thing about shellac is that it's easy to repair and most shops have an ample supply of it. Sticks are easier to use for this procedure but any shellac will work.
Super glue is very difficult to undo. Wax has a reputation for failing in warm/hot conditions. Maybe Buffet uses wax, but they've also been using other questionable materials of late -- in my opinion :
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Author: Willie
Date: 2002-11-23 00:39
I had an old Vito that would not play hardly at all though it had all new pads and new, tight fitting corks. It passed the pressure/suction test with no problem. I then starting with the mouthpiece tenon, "over gooped" the tenons and tested one at a time. It seems the upper tenon cork, though new was sanded to an oval shape rather than round. I recorked it and was good as new.
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Author: Wes
Date: 2002-11-23 05:24
Yes, George Jamison was quite an expert on woodwinds. As I understand it, the NX clarinet was designed so that there were fewer or no toneholes directly beside each other. It was my understanding that Arthur Benade did the acoustical design and George built it. The toneholes would be located as far from one another as possible by angularly rotating their position around the clarinet tube. George demonstrated it, saying that the low register notes did not vary much in pitch with volume level as on most regular clarinets. The reason for this is not clear to me.
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