 The Clarinet BBoard
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Author: knotty
Date: 2015-05-10 20:34
Before I took a few year haitus from learning clarinet repairing, I was working on finding airleaks. Have used various methods, string of lights, cigarette/mylar strips, blowing in the joints. I found generally the cigarette paper the most helpful.
Do you use multiple methods to find leaks or rely on just one?
Thanks!
~ Musical Progress: None ~
Post Edited (2015-05-10 20:37)
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Author: BartHx
Date: 2015-05-10 21:17
I use cigarette paper when seating the pads and double check with vacuum when the joint is finished. It is rare that suction finds a leak that I missed with the paper.
On the other hand, I live in the Sierra foothills to the east of you (where pot farms are found in the national forests). The last time I purchased a pack of cigarette papers was during a short break I took while working on one of our cars. I went into our local two pump gas station with a small convenience store wearing my dirty coveralls. I did get some strange looks when I asked for cigarette papers.
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Author: Tony F
Date: 2015-05-10 21:33
I use a leak light to sort out the major leaks and then mylar film and/or cigarette papers to fine-tune. I don't have a vacuum rig but I find I can generally get it right. Porous wood can sometimes be a problem, but rubber bungs in the bore and tone holes and a blow in soapy water will generally find it.
Tony F.
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Author: Caroline Smale
Date: 2015-05-10 23:52
After cig papers I use a suction test (very light vacuum) to help assess leaks but when all else fails removing keys one by one and sealing the tonehole(s) with blutack (or other bung material) is sometimes needed. This is especially case when leak turns out to be actually past a tonehole bush e.g. thumb or speaker tube and also some instruments have separate tonehole chimneys.
On one accasion it even showed up a small wood crack invisible underneath a tenon cork.
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Author: Johan H Nilsson
Date: 2015-05-11 01:56
I use a MAG machine. That's the only way to quantify the leakage and follow it up. I can also plugin a clarinet and instantly know if it needs to be fixed.
It also helps finding leaking pads. Just press them gently one by one and see if the value on the MAG changes.
In the rare cases I cannot find leaks this way I plug the finger tone holes and submerge the clarinet a few seconds into room-temperatured water with the MAG going.
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Author: knotty
Date: 2015-05-11 04:11
Thanks all for the replies. I found my box of repair things today, quite a few pad sets from Musicmedic so won't be needing pads for a while. A few years ago, I got repair practice clarinets from that auction site, no high end clarinets but a few Bundy's, Vito's, Selmer Signets, Yamaha's, and a number of others.
As I recall now, polishing keys, dis-assembly, re-assembly was pretty straight forward but a more difficult phase was adjusting them, finding air leaks etc.
Thanks!
~ Musical Progress: None ~
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Author: Paul Aviles
Date: 2015-05-11 05:48
Of course for pesky problems that you just can't seem to diagnose, the last ditch effort would be to take off all the keys of the offending joint, tape the holes (plastic tape; electrical tape) and check that first, then start adding keys from the top going down (one tape off, one key on). That method NEVER fails.
..........Paul Aviles
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Author: cyclopathic
Date: 2015-05-11 07:01
In this order: light, paper strips and blowing test (good bell plug rules!). If there are still issues blowing test + mic.
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Author: Chris P
Date: 2015-05-11 08:42
On clarinets, oboes and piccolos which I use cork pads on as standard, I use feeler gauges cut from the finest weight cigarette papers (I use silver Rizlas which are half as thick as the blue ones) to check the pads are seating all around their respective toneholes and do a suction test to be certain - if the vacuum holds for well over ten seconds then that's what I want. It's saddening to find some brand new clarinets will barely hold a vacuum for three seconds if that - and that's only the top joint.
In isolating leaky pads or other hidden leaks I plug up all the toneholes with Blu-Tack and install the keys one at a time and do a vacuum test to find the culprit if it's a leaky pad. If the joint leaks with all toneholes plugged up, then a pressure test with the aid of soapy water will show where the leak is if it's a pillar leak, slot leak or tenon leak.
I have used mag machines in the past, but to be honest if I can get a vacuum to hold that exceeds ten seconds on a joint or an instrument that's cork padded, then to me that's as near to a 0 reading on the mag machine as it gets.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: clarnibass
Date: 2015-05-11 11:04
I use all the methods mentioned so far. I don't use a smoke test since I wouldn't want a clarinet to smell of smoke.
A light is good for some more obvious leaks, or when pads are not transparent, or when the leak is not on the top/bottom of the tone hole (in relation to the clarinet length) where the walls of the coutnersunk area block the view, or when another key doesn't block the view.
I've tried many feelers. I prefer under 0.015mm thickness. Paper tends to tear or get ruined more easily. Cassette tape tends to curl. Some plastics (e.g. mylar) tends to get an annoying static charge (including types advertised as static resistant). Some other plastics I've tried (many) have a too smooth feel. So I choose the best compromise of these options... after years I'm still undecided...
A feeler is good to find most leaks but not ones that are thinner than the width of the (already very thin) feeler.
A magnehelic isn't really quntify the leak in the usual sense. It's only compared with itself. Two mag machines, even the exact same model, can show differences even with a slight difference in set up (even when they are set up to the same specs).
The main reason I use one is to not put my mouth against so many clarinets.
I consider that the "squirting air" method, as opposed to sucking/vacuum or blowing, is very accurate and can replace a mag machine in accuracy, as long as the person doing it is sensitive enough to feel it. You squirt air from your mouth/throat without blowing up your cheeks. This can be tiring quickly, which another reason to use a mag.
To find some body leaks and many other difficult ones, there's the method Paul mentioned, except I use silicone or rubber plugs instead of tape. If the joint shows a leak with all keys off, this method can show it, but you need to do something else to find where it's coming from.
Submerging the joint in water can do that and unlike what some people tend to think, it doesn't damage anything.
Sometimes the leak is from a key but still difficult to find using one of the above method. One thing that you can do is close all the holes and keys and fill the joint with water, so it doesn't get to the outside. Empty the joint (from the same top hole you filled it from), making sure no water gets on the outside. Then squirt/blow air into it and it will bubble from the leak, sometimes getting a bit of water from it too.
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Author: Lelia Loban ★2017
Date: 2015-05-11 16:13
BartHx wrote,
>I did get some strange looks when I asked for cigarette papers.
>
Yup -- and a a student might get much worse than strange looks for carrying cigarette papers on school grounds. A good alternative to cigarette papers: camera lens-cleaning papers. They're about the same size and thickness.
Lelia
http://www.scoreexchange.com/profiles/Lelia_Loban
To hear the audio, click on the "Scorch Plug-In" box above the score.
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Author: Chris P
Date: 2015-05-11 16:26
The last time I used a mag machine was simply to pressurise a leaky oboe top joint to find a leak - by submerging the joint in a glass of water and watching where the bubbles emerge from. I've since used a piece of plastic tubing with an oboe staple fitted to the end and a bike pump to do the same thing without the expense of a mag machine. So a mag machine would just be an expensive bit of redundant kit to me.
On saxes I use a leak light down the bore to check and adjust pad seatings and regulation.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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