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testing an oboe seal

Author: Bobo
Date: 2007-04-29 16:05

What does the group think is an acceptable standard for testing the seal of the oboe's top joint?

To get started, I'll volunteer the following:

1. I test the top joint seal by covering the three tone holes with my left hand, covering the tenon with my right index finger, and sucking the air out of the top until the tip of my upper lip is stuck in the reed well...then i depress the g sharp key with my pinky and wait to see how long it takes for the g-sharp vent to open up as the internal vacuum gives way to the external air pressure.

2. I find that if my oboe hasn't been played on for many days (and is cold), I achieve almost no seal.

3. But with a recently played and especially a properly warmed up oboe, I can achieve a seal of anywhere from 15 to 23 seconds.

4. My oboe has two quite lengthy cracks along the sides of the top joint (not running through any holes), that were pinned shortly after i originally bought the oboe 32 years ago at Loree. The cracks are clearly visible on the outside but looking inside the bore I see no evidence of a crack through to the bore.

5. An "expert" repair person with a very good reputation blew smoke through the top joint and told me it was shot and the keys needed transferring to a newly tooled top joint (Loree apparently still has the reamers and blueprints for this operation and would do it for a hefty fee, merci beaucoup)...

6. I'm extremely skeptical since the oboe still plays quite nicely and as I said can hold a seal at least for some length of time.

So, the question is...what is the best way of testing the seal and what is an acceptable seal? I'll note that over 70 years ago, Marcel Tabuteau, according to an old IDRS article, required the top joint to hold a seal for over 30 seconds using the technique described above! The same article says that many current manufacturers only require a seal of up to 5 seconds; this i find hard to believe...

This very interesting article can be found at...

http://www.idrs.org/WWW.IDRS/Publications2/DR2/DR22.1/102.great.pdf

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testing an oboe seal new

Bobo

2007-04-29 16:05