Looking for Besson Meha piston (Kanstul)



  • I have a Meha where the first valve piston is shot. My tech says it's smaller than the other three, that's why it sticks on the way up - someone must have replaced it or honed it down too much.
    Since it's Monel, adding more material by plating would be hit-or-miss, it might come unstuck eventually, he says.

    Does anyone have a junker lying around? Maybe one where the red rot has eaten away everything but the pistons... 😄

    Kanstul, being in the process of closing shop, were not able to help me. They just have a sales guy and a lady doing the books, apart from Jack. They're selling off surplus mouthpieces at the moment, looks like.


  • Qualified Repair Techs Credentialed Professional

    Don't know why your tech says by hit-or-miss. The majority of valves are monel and the experts have no difficulty plating them. Unusual for the piston to wear so much, normally the majority of the wear is in the casing. BAC in Kansas City bought all the Kanstul stock, they might have something. But you might want to get a clearer diagnosis and have the casings and piston dimensions mapped out before shelling out on a new piston.



  • @Trumpetsplus Thanks for your viewpoint.
    I guess it partly comes down to how much a piston would cost, if it's worth taking a chance on it.
    Re-plating is quite expensive in my locale (Sweden) so I'm hesitant to do it even if it usually works well. The horn is really nice though, if only that valve worked... Plays excellently up high, more nimble than my Xeno somehow.



  • @Jolter said in Looking for Besson Meha piston (Kanstul):

    Re-plating is quite expensive in my locale (Sweden) so I'm hesitant to do it even if it usually works well. The horn is really nice though, if only that valve worked... Plays excellently up high, more nimble than my Xeno somehow.

    Wat do you find quite expensive?

    A few years ago (november 2017) I shipped an Olds Super to Charlie Melk in the USA, he did a valve job for the 3 valves, minor dent work and aligning the 3nd tube. It costs me all together €550.- that is incl. shipping. If just one valve needs replacing I bet it will cost you less

    The Olds returned technically like new 🙂


  • Qualified Repair Techs Credentialed Professional

    I am still interested in knowing the dimensions.



  • Trumpetsplus (maker Ivan Hunter) and Charlie Melk and James Becker at Osmun music might be able to advise you best as to how to proceed.


  • Qualified Repair Techs

    Dan Oberloh in Seattle, who I apprenticed with, also does a lot of valve jobs with plenty shipped from overseas. You could contact him as well.



  • @Trumpetsplus said in Looking for Besson Meha piston (Kanstul):

    I am still interested in knowing the dimensions.

    Good call.
    My tech tells me (my translation: "Your horn has probably had an accident and someone replaced valves 1 and 2. I feel there is too much play in 1 & 2, at 0,05 mm compared to only 0,02 on number 3"

    Actually only valve 1 sticks, number 2 seems to work fine.

    There is corroborating evidence that there was an accident: when I got the horn off eBay, the bottom valve caps were replaced with heavy caps. But what's more, the threads on the valve casings were dented to the point where one of the caps wouldn't reliably come on and off. I got that fixed by a different local tech, but I only asked him to fix the threads as I hadn't really noticed the sticking yet, then.

    Myself I have no idea why the dimension are different. It's certainly possible they were replaced, but I suppose another explanations might be that the casings were damaged and someone did a poor job of straightening them, perhaps including excessive honing/lapping?

    Would you happen to know how much play there normally should be in a Kanstul piston?

    Would re-plating and re-fitting the pistons be a surefire way to fix this, you think?


  • Qualified Repair Techs Credentialed Professional

    A new trumpet will have a difference in diameters, piston to casing, of around 0,015mm. At 0,04 you are looking at a refit. When the clearance is this great the wear is normally in the casing. That wear is not only egg timer shaped, greater at top and bottom, but also oval (greater sideways than front and back). The remedy is to hone the casings true and round, then plate the pistons up to the new diameter.

    Worn valves on a trumpet normally cause plying issues before sticking issues.



  • @Trumpetsplus said in Looking for Besson Meha piston (Kanstul):

    Worn valves on a trumpet normally cause plying issues before sticking issues.

    Yeah that's what I've heard before, too. I don't really think I've experienced any leakage at all with this horn, because it plays beautifully across the whole range and I find it to compare very favorably to my Xeno in most respects. The exterior is not very worn at all, in fact the plating is near perfect and there are virtually not dings on it, so I'm hesitant to say this was caused by normal wear on the valves. Of course, it could have been a very careful previous owner. (Apart from that drop on the bottom caps.)


  • Global Moderator

    @Jolter There is a Besson Meha for sale at Votruba's shop in Vienna. I've test played it, and it's one of the really good Mehas... here's the link: https://www.votruba-musik.at/gebrauchte-instrumente/trompeten-fluegelhoerner.php



  • @barliman2001 said in Looking for Besson Meha piston (Kanstul):

    @Jolter There is a Besson Meha for sale at Votruba's shop in Vienna. I've test played it, and it's one of the really good Mehas... here's the link: https://www.votruba-musik.at/gebrauchte-instrumente/trompeten-fluegelhoerner.php

    But did you try the Benge?

    (Thanks for the tip, but right now, I don't have the money to spend on a valve job, much less on a new Meha...)


  • Global Moderator

    @Jolter It's nice; but then, I've got a very, very nice Benge #7 sitting at home...


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