 The Clarinet BBoard
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Author: Tony F
Date: 2015-12-27 10:08
A while back I bought a lovely old JTL clarinet. Comparing it with the catalogue it looks to be around the beginning of the 20th century. The pads were a bit elderly, but the wood and keywork were perfect. It's obviously been used but not abused. It's Bb, low pitch.
I noticed that when playing at the bottom end of the chalameau register it would occasionally switch to clarion register without any action on my behalf. I figured there was a leak somewhere in the upper joint, and that is what prompted me to repad it. It's not a squeak as such, it's just as though I had pressed the register key.
Today I repadded it with good quality double bladder pads, but after fixing the odd leak it still jumps to the clarion register. I went back to leak-chasing, but to no avail. I've tried different reed/mouthpiece combinations and even a different barrel, but it still persists. The wood is dense and in perfect condition and both joints now hold a vacuum when doing the suck test. The cork joints are good.
I've about run out of ideas now. Can anybody suggest anything I may have missed, or is this a characteristic of old narrow-bore instruments?
Tony F.
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Author: Ken Shaw ★2017
Date: 2015-12-27 10:20
Tony -
You obviously have a leak. If the top and bottom joints hold a vacuum, then there could be a crack in the barrel. Another possible problem is a misadjusted bridge key or a leak around the register vent.
Ken Shaw
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Author: clarnibass
Date: 2015-12-27 11:15
How did you check for leaks that are not from the pads? There are many possibilities.
First, when it happens, try to see what part of the range it affects. Unless you stop playing, start the same note again and it suddenly works fine...?
- Pad swelling and leaking only sometimes
- Almost invisible chips and cracks/grain in the tone hole seats
- Register vent or thumb tube leaking
- Leaks from under posts or any other metal parts, even if they are not drilled into the bore
- Any drilled or cut areas in the body, like blind holes for flat spring screws, etc. can sometimes leak
- Random holes in the body itself (I've seen this, barely visible with a magnifier)
- Grooves or deep grain in the tenons/sockets
- Mechanical leak (e.g. friction in the throat A flat spring, trill key touchpieces touching, any key rubbing against another, etc.)
Post Edited (2015-12-27 11:20)
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Author: Tony F
Date: 2015-12-27 13:10
Thanks Guys,
This thing is driving me slowly nuts.
The problem shows as thus. playing is normal until suddenly, with no warning and no change of embouchure it jumps into clarion register. It mostly seems to happen around G below the stave. The instrument seems to be very sensitive to slight changes in embouchure. I don't suspect the barrel, as I've tried several, likewise the mouthpiece.
I tested for leaks initially using cigarette papers and a leak light. With all of those set up it would hold a vacuum for several seconds, which is better than most of my other instruments and they work. All pads are new, so its probably not a pad, although it can't be excluded. I checked each individual tonehole/pad by sliding pieces of cling-wrap under the pads. I've found this to be a good way to isolate leaks and check tone-hole condition. The bridge adjustment is OK.
Tomorrow I'll remake the joint corks, and if that doesn't fix it I'll strip the keys off and pressure-test it underwater with plugs in the holes. This should show any body porosity or other leakage. It will also allow me to check the condition of the tone-holes, although they looked OK when I repadded it.
Tony F.
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Author: Clarineteer
Date: 2015-12-27 16:10
Use someones Mag Machine and you will find out which pad or pads are leaking immediately.
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Author: Chris P
Date: 2015-12-27 19:26
I'd ditch the skin pads in favour of leather pads on a clarinet of this age as they will take into account imperfections and unlevel toneholes much better than skin pads, plus they're much harder wearing than skin pads. But ultimately with any clarinet overhaul, the toneholes do need to be addressed and all the tiny nicks and surface vessels running across them need filling in, then the whole tonehole levelled so you can seat a pad on there with no leaks.
But choose good quality leather pads that aren't too soft and aren't porous - while saxes really suffer with sticky pads due to them being made with plastic coated leather (and sax pads have more contact area for each pad compared to clarinets), it's much less of a problem on clarinets provided the toneholes are cleaned and degreased before installing leather pads.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: Tony F
Date: 2015-12-27 20:02
I think I've nailed it. The A pad cup had cracked where it joins the key arm. The key cups on this clarinet are much thinner than on modern instruments. In this case, when the pad,key were static it sealed well, but dynamically as soon as you played the key the cup flexed and leaked. A dab of silver solder sorted it. Unfortunately I can't test it until tomorrow, as my other half has a very low tolerance for clarinet players after midnight, but I have great confidence. Thanks for the suggestions, some very useful stuff there.
Tony F.
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Author: LarryBocaner ★2017
Date: 2015-12-28 02:25
I had the same problem with my c.1897 JTL clarinet, the weekend before a recording session. Turned out I had a crack in the upper joint that opened up only after several minutes of playing -- otherwise virtually invisible. Fortunately for me, my favorite tech, Tony Valenti, finished pinning the crack just hours before the first session -- instrument stayed tight for a whole week of recordings.
Incidentally, this CD is the end result -- just released last month. If you want to experience 19th Century American band music played on all original instruments -- I'm sure it's worth your money.
http://www.amazon.com/Thomas-Coates-Father-America-Instruments/dp/B017GEAOSU/ref=sr_1_1?ie=UTF8&qid=1451254925&sr=8-1&keywords=thomas+coates+the+father+of+band+music+in+america
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Author: Ken Shaw ★2017
Date: 2015-12-28 04:47
Larry -
On the album cover photo, the clarinets are Albert system. Is yours Albert or Boehm? Also, HP or LP?
Ken Shaw
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Author: Tony F
Date: 2015-12-28 08:35
Just a follow-up on the problem. When I tested it this morning it worked fine, so the cracked pad cup seems to have been the problem. Larry, as a matter of interest I have in my "get around to it one day" box a nice old JTL high pitch Albert Bb.
Tony F.
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Author: clarnibass
Date: 2015-12-28 08:50
>> Use someones Mag Machine and you will find out which pad or pads are leaking immediately. <<
I have a mag machine and that's only true sometimes. It essentially tells you if there's a leak or not, which you can tell with the "air squirt" test pretty much the same. The mag itself doesn't tell you where a leak is coming from, it just makes it easier to check.
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Author: Tony F
Date: 2016-01-13 02:37
Larry Bocaner wrote
"Incidentally, this CD is the end result -- just released last month. If you want to experience 19th Century American band music played on all original instruments -- I'm sure it's worth your money.
http://www.amazon.com/Thomas-Coates-Father-America-Instruments/dp/B017GEAOSU/ref=sr_1_1?ie=UTF8&qid=1451254925&sr=8-1&keywords=thomas+coates+the+father+of+band+music+in+america"
Hi Larry,
Just received the CD. Some nicely played music of the 1800's.
Tony F.
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Author: LarryBocaner ★2017
Date: 2016-01-13 19:42
Thanks, Tony; glad you enjoyed it. Hope some other BBoard members will also get the CD.
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