 The Clarinet BBoard
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Author: corks&pads
Date: 2006-05-10 16:18
Even if you don't plan to repair clarinets, having a leak light handy is a good thing for anyone who plays. Someone recently posted a thread about a new clarinet not playing well. I'll bet one of these would quickly explain to them why it isn't.
The first leak light that I bought was cobbled together by a supply company from a decorative lighting "snake." It was too thick, clumsy, and downright dangerous (voltage involved and not built safely).
You probably have most of the stuff for making this in your basement or closet, or you can find it at a hardware store / electronics store / or yard sale.
This stuff doesn't require a degree in electrical engineering, but if you aren't entirely sure what any of these components are, ask your Mom to help!
LIGHTS
The little MINI Christmas tree lights come in a couple of different voltages. The most common ones are about 3 volts, but the ones used in latern strings (chili peppers, Winnie the Pooh characters, etc) are 12 volts. Spare white 12 volt lamps can be bought at Ace hardware stores (or other chains).
SOCKET
Nearly everyone has a string of mini Christmas tree lights that aren't working. Clip three or four sockets from one of those, leaving the two wires about 4" long, and either give the rest to a friend or toss them out.
POWER
I'll bet that you have an old portable phone, tape player, game, or other broken electronic device that came with a power supply -- one of those things that usually has a black plastic box that plugs into the wall, with a cord and jack that plugged into the device. Those have voltage ratings written on them. Anything from about 9 to 13 volts will work. The key is not to use something that has an output higher than that, or to use standard 3 volt tree light bulbs with 9-13 volts of power (there will be brief, bright, light...then the lamp is gone!).
Cut the jack off the end of the supply wire, leaving as long a wire as you can.
ASSEMBLY
If you want to be neat about it, strip about 1/2" of wire off all four cut ends (2 on socket, 2 on the power supply wires). Slip a 1" piece of shrink tubing over each of the socket wires and slide them to the socket, twist the 2 power wires onto the 2 socket wires (doesn't matter which is on which...lamps don't really care), solder the things together, slip the shrink tube over the bare wire, heat until shrunk, and you are there.
If you don't have soldering gear and shrink tube, twist the wires together and tape over the connections liberally with electrician's tape. If you are using the correct power supply, we aren't talking about voltage that's going to zap you anyway.
USE
Go into a room that you can make dark, taking your joints with you (Can I say that, Mark?). Plug the power supply in and stick the light inside one of the joints. Turn off the room lights. Maneuver the lamp so it is under one of the closed pads, then look carefully around the edges of the pads where they contact the tone hole.
Skin-covered felt pads will glow pleasantly. Leather pads won't glow so much.
If there's an obvious leak, you'll see a little sliver of brighter light at some point around the circumference of contact than elsewhere on that pad. In less conspicuous cases, the glow will appear brighter in one area than others on that same pad.
That will be at least some of your problem, and maybe all of it. Take it to your repair tech unless you know how to replace the pad yourself.
Post Edited (2006-05-10 16:25)
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Author: tictactux ★2017
Date: 2006-05-10 16:38
Cool, that really sounds do-able.
Alternatively, you can use a bright LED, a resistor and a 9V block battery. (They have the advantage of not getting hot while lit and use a whole lot less power. But you need a soldering iron)
Here's a short page including a how-to-calculate the suitable resistor value
http://www.kpsec.freeuk.com/components/led.htm
--
Ben
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Author: corks&pads
Date: 2006-05-10 17:00
Good point about the heat, Ben, but I've run one of the 12 volt mini lights on a 12 volt power supply for 20 minutes+ and it was only slightly warm to the touch--certainly not enough to come near hurting anything.
Another advantage over LEDs is that the mini lamps give off light in almost all directions, where LEDs tend to be more directional...might have to "bend" the LED about 90 degrees to get it to shine directly through the tone hole.
Yet another possible advantage is that the "white" light of the mini may be easier to see coming through a leak than the bluish-tinted light produced by the stronger LEDs that I've seen. Not at all sure about this one, though.
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Author: stevensfo
Date: 2006-05-10 17:24
I cannot see what's so good about leak lights. The one time I tried one, I noticed that in any case, some light does come through the edge of the pad. Also, it doesn't show how 'strongly' the pad is sealing.
Thus, a leak light may indicate that there is no leak, but as soon as you blow, the pressure may force its way past a pad.
I prefer to simply seal the end of each joint with something and blow, while feeling for escaping air. Then a quick tour with some cassette tape.
But I'm willing to be corrected on this. I'm certainly not an expert! ;-)
Steve
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Author: Chris P
Date: 2006-05-10 17:38
I'm using a 12" fluorescent tube for saxes which was originally an inspection lamp used in car engine bays - this gets warm through use, but still only warm enough that it can be hand held without being uncomfortable if you want to re-enact Star Wars with it.
I've rewired it to a 12 volt adaptor that can be bought from any electrical supplier, but it still needs the starter to get it working, and this is easy enough to connect up to the power lead between the adaptor and the tube, then connect the terminals but tape one wid=re down the length of the tube to reach the far end terminal, then cover the ends with amalgamating tape to keep them insulated. Replacement tubes are easy enough to buy - minicabs use the same tubes in their roof signs.
I'd like a high powered LED rope light so I can use it in baritone saxes where a glass tube won't go inside unless the bell is taken off - but only if the bell can be taken off, so Conn X-Bars are a pain unless the top U-tube is taken off.
However, I don't use leak lights on flutes, oboes, clarinets or bassoons.
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Author: David Spiegelthal ★2017
Date: 2006-05-10 17:50
Leak lights work much better on instruments equipped with opaque pads such as leather or cork -- another of the multiple reasons I prefer leather pads to bladder (a.k.a. 'fishskin').
For instruments of larger diameter than soprano clarinets (for which the inward-protruding register vent tube impedes passage of the leak light), the cheap decorative rope lights sold in hardware and department stores work fine -- great for instruments with 'loops' such as bari saxes and contra clarinets.
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Author: Gordon (NZ)
Date: 2006-05-10 23:50
Random thoughts and experiences:
1. A leak light needs high LOCAL brightness, right beneath the tone hole. Strip lights and fluoros are poor at providing this, compared with say a 4.5 volt, .75 amp torch bulb. Without strong LOCAL brightness, a lot can be missed.
2. "Krypton" (a type, not a brand) torch bulbs are brighter and last a lot longer than standard torch bulbs, although krypton is gradually becoming more standard.
3. I agree that leaks can be missed unless the room is darkened. I agree that LED's - all the ones I have met - are too directional.
4. I agree that they are poor for detecting leaks under bladder pads. This is because such pads are translucent, so the light leaks through them. Most technicians do not use them for bladder padded instruments.
5. I used mine only once ever on a clarinet. IMO they are all but useless on a wooden or plastic clarinet, because by the time the light has negotiated (in straight lines only, remember) up a relatively long, relatively narrow, very dark-and-rough--walled (hence non-reflective) tone hole, and then somehow turned a corner to exit under a pad, there is almost no light left.
I use them only for saxophones. I would use them on metal flutes and clarinets only if the pads were opaque. This may be an advantage of the "j L Smith" gold-covered membrane pads for flute. :-)
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Author: corks&pads
Date: 2006-05-11 17:02
The commericial one that I bought didn't work well at all on bladder pads, but the one that I described making does. (That's why I posted ithe "How To".) I wasn't posting this info for the well-equipped repair tech as much as I was for those of you who tend to acquire "new" instruments and want to see if it's likely that sending the thing out to a repair tech might improve how the new horn plays.
On the other hand, since this is made with a different sort/size of light source than others here have described, maybe the size and intensity of this one will work better than what you have experienced.
Maybe I'm just particulalry good at discerning subtle differences in light intensity, but I doubt it. This has worked pretty well for me on wooden and metal horns. Because the lamp and socket are small, I can maneuver the lamp directly under the tone hole and light it up pretty effectively. Sometimes a problem is readily apparent. Sometimes it just looks a little suspicious, so I dig out the cassette tape leader strip. In any case, it only takes about 10 minutes to check the pads out on a clarinet.
No, it's not a perfect diagnostic tool, but it's cheap, and it's better than nothing. Works for me ... your own mileage may vary ... and you certainly can't argue about the price for the design and directions for construction.
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Author: tictactux ★2017
Date: 2006-05-11 18:41
No, it's not a perfect diagnostic tool, but it's cheap, and it's better than nothing.
The good old bicycle tube test (aka watch the bubbles!) is even cheaper. 
--
Ben
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Author: BobD
Date: 2006-05-11 23:01
I haven't thought much of leak lights for clarinets and thought it was just me. Darkening the room adequately is a problem.
Bob Draznik
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