 The Clarinet BBoard
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Author: WoodsyBloom
Date: 2022-07-26 01:29
My friend was playing his bass clarinet next to me at marching band camp today. He complained about his C#/G# sounding funny and a minute later he discovered a massive crack in the area that quickly expanded and rendered the instrument unplayable. The crack was at the lower part of the upper joint and ran parallel to the ring where the joints meet. I've only seen cracks running up and down an instrument before and only in wooden instruments. The school has us playing Yamaha YCL-221 low Eb's for marching band specifically because they're not supposed to crack. My band directors are convinced the crack is his fault and that he dropped or didn't take care of it properly. I, however, witnessed the event and and know this is not the case. I'm hoping for a reason that this can happen to present to my directors so they don't charge him $3,000 to replace the instrument.
Information about the bass clarinet:
The school has had it for about six years.
It's played heavily August through December and hardly at all the rest of the year.
We live in Texas. It's hot.
It's also gotten to experience 30/40 degree weather.
We do choreo in our marching shows that require putting it down on pavement very quickly and roughly.
So how does this kind of thing happen to a plastic instrument?
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Author: Hank Lehrer
Date: 2022-07-26 02:16
Hi Woodsey,
In aviation, we call that a "Brute force disconnect."
Hank
CFII & ME, ATP:C500
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Author: Tony F
Date: 2022-07-26 03:25
Almost any of the circumstances you mention could result in a fracture as you describe. They are musical instruments, not a piece of sports equipment. As to
"not supposed to crack", that is what I would expect if they were used as intended. I've seen several bass claris cracked exactly as you describe. They were all school band instruments. It's a relatively easy fix, though. The damaged tenon can be re-sleeved with Delron, I have such a repair on my Noblet bass clari.
Tony F.
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Author: Steven Ocone
Date: 2022-07-26 16:03
Common issue. There is a lot of leverage operating at that joint. There doesn't have to be a lot of force to break the clarinet. Delrin isn't the best material to used to fix it. ABS is preferable. (Delrin doesn't bond well with glue.)
Steve Ocone
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Author: SunnyDaze
Date: 2022-07-26 18:57
Woody - if you printed the thread and took it in, do you think that would help?
Or do you need us to write a more diplomatic version, so as not to put the band directors in an awkward spot that makes it hard for them to back down? Giving the band directors a way to back down without looking weak is an important part of solving this problem, I would think.
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Author: Hunter_100
Date: 2022-07-26 19:38
There is a type of failure called a fatigue crack that does not require a "drop" or large impact to break the instrument. Essentially what happens is a very small defect or microscopic crack gets formed in the plastic at some point, and slowly expands every time the instrument is handled. It could take years for such a crack to expand to the point of causing a noticeable failure. Since the instrument has been in use for 6 years, the original damage could have been from an earlier student user or even a manufacturing defect. Fatigue failures don't usually happen in wood, but they are very common in plastic and metal parts.
If you can provide a good quality picture of the fracture surface, it would help with a diagnosis.
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Author: kdk
Date: 2022-07-26 19:40
It sounds from Tony and Steve's comments as though this is a common
and perhaps relatively inexpensive repair. So, to prevent the band director from reactively replacing the instrument as destroyed, your friend should get a local repair person (or two if they're available) to give an estimate for the repair and take that to the director. That should at least whittle the cost down significantly.
But to play Devil's advocate at least in part:
When we in my school district lent out district-owned instruments, we included an agreement that the parents signed taking responsibility for the instrument and promising, in place of paying any rental charge for the instrument's use, to have it repaired if necessary at the parents' expense. Since most of the kids in the program were either buying or renting their own instruments, this was considered a fair trade-off for use of an instrument at no cost.
In practice we never charged a family anything unless damage was caused by really clear negligence on the part of the student or the parents, like driving over the instrument or trying to repair something at home and making things significantly worse instead.
Karl
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Author: Chris P
Date: 2022-07-26 20:31
While plastic instruments are 'not supposed to crack', that only means the top joints won't develop cracks when subjected to sudden or extreme temperature and humidity changes which wooden instruments often suffer.
Only those cracks or splits run along the natural line of the grain and not against it and mostly affect the upper end of the top joint from the top end and can run through and terminate in toneholes.
While plastic or composite instruments (including Greenline as it's essentially wood dust mixed with glue) are impervious to this kind of cracking/splitting as they don't have the same natural grain structure that wood has, but they do have an inherently weak area which is the middle tenon where the plastic is at its thinnest and subjected to a lot of undue stress.
Some plastic basses (eg. some Vitos) have metal reinforced middle tenons to give this weak area the strength it needs, but on an unlined/non-reinforced tenon, it doesn't take much for them to shear off through stress either through a simple knock or from a fall.
One-piece body plastic basses will be stronger as they don't have the weak middle tenon or socket, but they do have a couple of weak points where the three Eb/Bb toneholes (side and LH3 Eb/Bb toneholes and the LH2 tonehole), or where the two F# toneholes (LH thumb hole and side F# key) are located which are in the same plane.
The options are a replacement tenon and preferably one with a metal reinforcement extending several inches along the length of the bore, or replacing the top joint (and transplanting the existing keywork onto it) depending which is more cost effective. Simply gluing the snapped tenon back on won't work, unless it's pinned with several stainless steel or carbon fibre pins which has also been done successfully and is the least costly repair compared to the last two.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: davyd
Date: 2022-07-29 00:15
What is ABS in this context?
I'm siding with Super20Dan. The bass clarinet has no place on the marching field. (When I was in HS marching band in Texas, all the double reed & low clarinet players were put on the flag line.)
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Author: Hunter_100
Date: 2022-07-29 03:36
ABS is a type of plastic used instead of wood or hard rubber. It stands for acrylonitrile butadiene styrene. It is not the same material as Delrin (which is a brand name of polyacetal).
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