Free Fowing 3rd Valve Slide

Discussion in 'Trumpet Discussion' started by stepjazz63, May 23, 2015.

  1. nordlandstrompet

    nordlandstrompet Forte User

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    Well..... compression, compression, compression...

    Guess what? There is also a common device called water clef/spit valve on the slide..
    This has a piece of cork..
    Guess what II? Cork is not 100,5% air tight....
     
  2. Dennis78

    Dennis78 Fortissimo User

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    I keep my corks oiled for optimal seal. It may make sense what I say but I'm not a trumpet expert, repair tech, or builder. My compresion guess comes from my experience working on cars. I have been an electrician for the last 15 years, but I do really think that I am right
     
  3. Sethoflagos

    Sethoflagos Utimate User

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    If there was a perfect seal between valve and casing, your valve oil would be unable to act as a lubricant, and your valve would seize permanently. Therefore the concept of 'compression' is only relative, not absolute. This is also true for piston rings.
     
  4. Dennis78

    Dennis78 Fortissimo User

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    Oil is part of the seal to my understanding. All I really know is some slides fall and some don't. If a given horn plays good for the operator then there is no problem
     
  5. Culbe

    Culbe Forte User

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    Normal

    My amando water keys are tight, I blew into the end of my slide, blocked the other end, and there was no leakage. So, I put my trumpet on it's end, and the third valve slide didn't go anywhere. After I gave it a tap, it slowly jolted down to the bottom. Now, I flipped my trumpet on end. My first valve slide with no key didn't go anywhere. But, when taped, it flew down instantly. Normally my first valve slide is faster, but not by that much.
     
  6. J. Jericho

    J. Jericho Fortissimo User

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    On my horns that don't have 3rd slide triggers, the slides stay in place, even with the valve depressed, yet they all move effortlessly when necessary. It just takes a bit of fine-tuning the inner-to-outer slide clearance and lubricant to make this happen. I would say that if gravity can move a slide, there is too much clearance, and there is a consequent and undesirable lack of compression, whether it's at the valve, the slide, or a combination of both. You can determine the source simply by plugging the bell with something that seals well (I use a handball, myself), blow into the horn, and listen to where the leak is. If you have trouble locating the leak, use a stethescope. Harbor Freight sells a ridiculously inexpensive one.
     
  7. Sethoflagos

    Sethoflagos Utimate User

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    If an oil film could supply an effective seal we would have no need of shaft sealing devices such as labyrinth seals etc., etc. And even these only reduce leakage to an acceptable minimum. Trumpet valves don't even have so much as a basic wiper seal. Just plain linear bearings relying on a partial hydrostatic seal from lubricant and minimum clearances.

    There is a compromise to be had. If you want ultra-slick valves and slides, you must keep everything scrupulously clean and use thin oils for lubrication to keep stiction to a minimum. But you must also accept a certain amount of air leakage (irrespective of the state of wear).

    If you want your slide to pass minimum air and move easily, but have just enough stiction not to fall under gravity, then the classic engineering approach would be not to use an oil, but an appropriate grease, which by definition doesn't begin to move significantly until a minimum threshold force is applied.

    Thicker oils (up to and including petroleum jelly) fall somewhere between. Less air bypassing than a thin oil, but more resistant to rapid movement.
     
  8. stumac

    stumac Fortissimo User

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    The best 3rd slide lubricant I have found after 30 years of trying all kinds is chain saw bar oil. I buy 5 liters at a time. If any one would like to try, PM me for my address and send an empty valve oil bottle, I will fill it and return at no cost.

    Regards, Stuart.
     
  9. tobylou8

    tobylou8 Utimate User

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    Most all of my horns 3rd slides fall when put on a stand and I want it that way. Those that don't, I work on until they do. Grease is thicker than oil, so if you want it to stop, use Hetmans #6 heavy slide oil. Mine are slick enough for me when I depress third valve and the slide falls quickly to the stop point. Same goes for 1st slide when equipped with a trigger/ring/saddle. Nothing to worry about.
     
  10. richtom

    richtom Forte User

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    This is not quantum physics. The slide should be loose enough to move easily but not so loose it would slide out when you are using a plunger mute and need to play any valve combination that requires the use of the third valve, like an Ab. Can anyone here actually hold the 3rd slide finger ring and a plunger mute with your left hand at the same time? Didn't think so.

    Unless, of course, you actually want to play a 1/2 step flat on that particular note.

    If the horn sits on a stand and the slide immediately slides to the stop, it is slightly too free and should be greased/lubed/oiled so it moves only a little or not at all. Using a plunger with this type of slide movement would be a very iffy event.

    This also has nothing to do with compression in the valve or a water key.

    There are many products actually designed for slides which can be bought in most music stores or on line. These products, when used properly, will not gum up your valves like products that are designed for an entirely different usage.

    Rich T.
     

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