 The Clarinet BBoard
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Author: Campana
Date: 2012-07-31 19:13
I suspect that my register vent tube is slowly sinking into the clarinet body.
Investigating a suspected leak from the register key I found that the circular edge of the pad was bottoming on the clarinet body due to a depressed ring being formed in the cork by the end of the tube.
i.e. as the end of the tube sunk into the cork, the rest of the cork pad touched the body of the upper joint.
Later I realised that the cork pad was nearly new and that the depressed ring was no deeper that one would expect.
Further observation showed there was hardly any projection of the tube above the surface.
Can anyone advise an average height of projection and how these tubes are secured.
B&H Edgeware/Bb/wooden/cork pad.
Many thanks
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Author: Caroline Smale
Date: 2012-07-31 19:48
On B&H instruments the vent tube externally has a very slight taper and is usually held in position with shellac.
A projection of about 1.5 - 2 mm should be OK.
If it does too far into the body this can be rectified by heating and removing the vent and then refitting with a little more shellac on it's exterior.
An alternative, if you don't want to remove the tube, is to carefully pare down the wood around the vent to increase clearance for the pad.
Beveling the circumference of the cork pad should also be done so that only the small area needed to close the vent projects down.
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Author: vljenewein
Date: 2012-08-01 01:05
Yep, I've got a Boosey & Hawke Edgeware grenadillia wood clarinet and I see the same thing. I was a bit concerned about it as well, but didn't know quite how to raise it without putting undue pressure on the wood body lifting it. Since it is shellac and heating it might loosen it. I would think that :
a] remove the key
b] heat the register with a soldering iron and genly raise it a bit from the inside and allow to cool back down.
Is this right?
Vernon
Jenewein Duduks Manufacturing & Research
www.duduk.us American made Duduks
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Author: Campana
Date: 2012-08-01 08:56
If the tube is on the move it probably means that the shellac seal is already broken and will not require heat to move it, only to re-seal it afterwards.
I have just measured mine's projection and it is down to 0.2 mm.
Also I don't like the sound of my clarinet anymore, the notes seem more lifeless/less vibrant than what I was achieving in the past. I am hoping that this is caused by too much tube projecting into the bore and will be corrected at the same time when I reposition the tube.
Post Edited (2012-08-01 08:59)
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Author: Campana
Date: 2012-08-01 14:00
I have just removed the vent tube, it removed easily without the application of heat.
"Tidemarks" on the tube suggested it had spent years with approx 2 mm protusion externally and approx 4 mm protusion internally...about right???
Advice about the repair would be appreciated. I am starting from scratch as I have no shellac available.
Do I need to purchase shellac in flake form?
Can I use clear nail varnish?
Anything else?
How do I apply it...tube only, bore only, or both.
It seems to me that with such a relatively tight fit the adhesive is going to be pushed off. Applying to the tube only will ensure that the surplus ends up on the outside for easy access to clean up...
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Author: vljenewein
Date: 2012-08-01 14:23
I would think either use low temp hot melt glue, add to vent tube after you've pulled it up too far, and press down to right depth before the hot glue cools down and should work....
Or, raise the tube, use Gorilla super glue and add it same way and press down to proper depth immediately and leave alone for a few mintues. If ever needed adjustment, acetone would loosen it... probably heat as well.
Vernon
Jenewein Duduks Manufacturing & Research
www.duduk.us American made Duduks
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Author: Mark Charette
Date: 2012-08-01 14:34
vljenewein wrote:
> If ever needed adjustment, acetone would loosen
> it...
and of course any finish around it would be destroyed as well. While Gorilla Glue has its (many) uses, I think this isn't one of them.
Shellac or beeswax is generally a good choice to use for register tubes.
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Author: vljenewein
Date: 2012-08-01 16:36
I would think that shellac would be the better of the two. If the clarinet were in a hot car for very long the pressure of the sping on the key would push the register tube back down further.
Vernon
Jenewein Duduks Manufacturing & Research
www.duduk.us American made Duduks
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Author: Caroline Smale
Date: 2012-08-01 18:44
Shellac stick is best but you could also use sealing wax (if they still use that in the USA).
I have several steel mandrels variously shaped to fit inside the speaker tubes I come across which I use to hold the tube during removal and replacement.
Any metal rod of approx size should be OK for replacement.
Place tube on mandrel and heat tube (I use spirit lamp but cigarette lighter flame should do trick) and wipe the shellac / wax stick over the exterior of tube and quickly slip it into vent hole and press gently until it seats at required depth then let it cool.
The excess wax/shellac can easily be chipped off once cold.
For tube removal I made a wooden lever that is sized to pivot in the bore and far end rests on inside end of tube.
Heat mandrel and place inside the vent tube then apply gentle leverage on inside end of tube, it should slip out quite easily.
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Author: Campana
Date: 2012-08-02 09:40
I repositioned the vent tube using hot glue ( because it was available) and mainly using the procedure outlined by Norman. I found loads of spindles and things that could be used as mandrels in my Dremel tool box.
I tried 2 mm but it didn't look right and the key didn't sit right. I reset it to 1.6 mm and everything looked perfect.
It now plays a lot better than it has for the last 3 months. It's as I remember it. After 6 months of steady progress, I felt that I was going backwards these last 3 months and was despairing. Thank you all for your input, much appreciated.
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