 The Clarinet BBoard
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Author: Clarineteer
Date: 2016-03-07 00:20
Why are the R13 tenons not designed smooth instead of the way they are with the ridges.
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Author: Paul Aviles
Date: 2016-03-07 00:28
If you mean the grooves under the cork, that is more surface area for adhesive to hold the cork. Otherwise I don't follow.
..............Paul Aviles
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Author: Tony F
Date: 2016-03-07 00:53
The idea of more surface area to hold adhesive doesn't stand up. It's a hangover from the days before cork, when twine was used to seal joints. Joint corks today are secured with contact adhesive which as its name suggests relies on contact between surface for its strength. With contact adhesives a smooth surface holds the cork much more efficiently whereas a grooved surface only contact on the top of the ridges. On my own instruments, whenever I come across a grooved tenon I turn it down smooth and use slightly thicker cork.
Tony F.
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Author: Caroline Smale
Date: 2016-03-07 01:33
This wavy groove style is only one of at least 3 I have seen on R13s. Fortunately they later stopped doing it.
When I meet this style I usually take off the very high points and bind and glue thread to fill the remaining cavity.
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Author: BartHx
Date: 2016-03-07 01:37
The sine wave pattern also makes it harder to fit a cork to the tenon. If you are going to compress the cork for full surface contact and then sand the surface of the cork flat after it is secure, the cork strip has to be cut just a bit wider than the recess measures. The wave pattern makes the actual surface slightly longer than the distance between the shoulders. I have only found that wave pattern on relatively newer Buffets. The older ones I have worked on have tended to have the more traditional narrow grooves.
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Author: Chris P
Date: 2016-03-07 02:03
Also, do Buffets have tapered middle tenons and sockets?
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: Caroline Smale
Date: 2016-03-08 00:38
Every Buffet I have worked on has had tapered tenons on upper, centre and bell tenons.
To date my attempts to get Buffet to explain their reason for this have been fruitless.
I can understand why it can be a good idea on the long joint tenon where it fits into the boot/butt joint of a bassoon but on a clarinet no, just an increasing pain as the tenon cork hardens and takes a matching taper profile.
Resultant attempt to tune by pulling the joints by a mm or so and everthing becomes wobbly.
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Author: clarnibass
Date: 2016-03-08 10:04
>> If you mean the grooves under the cork, that is more surface area for adhesive to hold the cork. <<
Only very long ago when shellac (or similar) was used to glue the corks. Now almost everyone (including the companies) use contact glue and the grooves are just not really helping in any way.
There are at least a few different types of grooves on Buffet clarinets. The wavy grooves, which are two or three "scoops", the sharper tiny grooves and somewhat thicker grooves. The "waves" are the worst and are best filled and turned to smooth. With the other types, maybe the cork digs enough into them to give more contact area... or not. A rough smooth surface is probably best.
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Author: Chris P
Date: 2016-03-08 14:31
Also on Buffet Prestiges, the metal tenon tip rings are too narrow to be a suitable fit in the sockets - tapered or otherwise, they should still be a good wobble-free fit without the tenon cork fitted.
Well fitting parallel sided tenons and sockets should be standard across the board on all clarinets (and oboes) as the tenon should telescope in the socket like a slide as a tapered tenon and socket arrangement will wobble if the joint is separated even by 0.5mm.
Bassoon bass joints definitely need a tapered tenon at the narrow end due to the bore taper which will make the tenon very thin at the shoulder if it's made parallel and the joints are thin walled. I've seen a broken one and there was only around 1mm thickness of maple at the tenon shoulder, so an inherent weakness in that design (can't remember what make it was).
Maybe it's about time I got a parallel sided socket reamer and sorted out Buffet middle tenons (and the tenons as well) so they fit correctly. Nearly every Buffet I've worked on has a rocking middle tenon.
But they can definitely do without the wavy and grooved tenon slots as they're not suitable for purpose considering the contact/impact adhesives we use nowadays that require a close fit. I've no idea what the logic is behind the wavy tenon slot design, but I take delight in machining them flat - likewise with grooved tenon slots. If the tenon cork had the same profile on it, then that would be fine as it will mesh in with no voids. But that's never going to happen and the cost of profiling cork strips with grooves or waves specifically for Buffets will be prohibitive.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: MichaelW
Date: 2016-03-08 20:01
I suppose the tradition of grooving tenons originates from the time before tenon corks came into use. With some of my older clarinets I still use coiled thread instead, and here indeed the grooves are necessary. See also the older thread: http://test.woodwind.org/clarinet/BBoard/read.html?f=1&i=401373&t=401246
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Author: Chris P
Date: 2016-03-08 21:11
Binding/lapping tenons with thread and also glueing tenon corks on with shellac may benefit from having deeply grooved tenon slots to provide good anchorage, but companies have for decades been using contact adhesives to make these throwbacks to the dark ages redundant long ago. So it's a wonder why some still insist in using this practice to this very day.
All the Buffets I've seen with the wavy tenon slots have had voids in the troughs and the contact point is only at the peaks, so far from ideal. Some makers have barrel shaped tenon cork slots so the cork strip will go on with little shaping/sizing done once in place which is alright so long as the surface is smooth and not deeply combed like on Leblanc clarinets that have both combed and barrel shaped tenon slots. And just like Buffets, I've machined them flat whenever I replaced the tenon corks on them.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: Clarineteer
Date: 2016-03-09 01:53
Also the shoulder on the bottom tenon of the top joint and the tenon on the lower joint bottom that fits into the bell were swollen so I had to remove some wood to attain the correct fit.
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