Can my valves simply be re-plated?

Discussion in 'The Rehearsal Room' started by MWoj, Jul 16, 2017.

  1. MWoj

    MWoj New Member

    Hello everyone!

    I recently acquired a 3-valve, Besson 'New Standard' EEb and I'm wondering about the valves. If they're worn and not sealing well, can they simply be re-plated?

    Thanks for any help anyone can provide.

    -Martin.
     
  2. Jack E

    Jack E Active Member

    First point is this, Martin; is there any reason that makes you think the valves are not sealing well - or is it just that the instrument is old, and may have had a great deal of use?

    In direct answer to your question; the valves could possibly be plated, but it may not help much, if at all.

    As far as I know, valves are either made of stainless steel or Monel metal. Monel is far more expensive than stainless steel, and is made of about two-thirds nickel and about one third copper, with small amounts of other metals. From what a number of other long-time brass players have posted, here and elsewhere, Monel valves tend to wear fairly evenly all around the circumference; stainless steel valves tend to wear more in line with the ports, developing a cross-section which is lobed, rather than circular, a bit like this:

    upload_2017-7-16_4-2-44.png

    though obviously not to that degree.

    You can tell if your valves are worn like this by unscrewing the top cap, lifting the valve clear of the locating notch inside which normally prevents it from rotating, and seeing how freely it turns. On my horn, which has Monel valves, once lifted they rotate freely. I'm told that in the case of worn stainless steel valves, when they take on that lobed shape, even if it is not visible to the eye, you can tell because the valve will appear free in certain positions, but feel very stiff when you turn it to other positions. I don't know how much wear and tear takes place on the valve, as compared to the valve bore; apart from anything else, it will also be affected by the metal used to make the valve, and what metal has been used to plate the bore that the valve slides in.

    As to what can be done;

    There is a process called metal spraying, where minute drops of liquid metal are sprayed onto a worn component via a very hot flame. This builds up the worn metal, but is not very accurate, so the renovated part must be machined or ground to the correct size afterwards, and - in the case of a worn valve - to the required polished finish. And there's the rub - because anyone who's worked with stainless steel can tell you, it's truly AWFUL stuff to try and machine accurately, and with a good surface finish! Rather than cutting cleanly, it smears and scuffs up at the drop of a hat (a firm I worked for which made stainless steel pumps was forced to use nothing but diamond-tipped tools in their lathes and milling machines!)

    However, this is where we fall back on the optimum solution in instrument problems; find yourself a repairer who is recommended by someone you trust, take it there for examination, and heed their advice. You can bet that they will have come across this problem before, and know the best way forward.

    If all or most of the wear is on the valve body, then it may be no more than a simple (if costly!) case of 'junk the old one and fit a new one'. Even if there is some wear in the valve bore itself, if not excessive, it may be that - with a new valve fitted - the valve oil used will be sufficient to seal any gaps.

    HTH, and best regards,

    Jack
     
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  3. MWoj

    MWoj New Member


    Thanks for your very informative and helpful reply, Jack! I took a look at my horn today, and I found the valves to rotate freely in their casings with no binding. I tinkered a bit and I think I may simply need a good valve alignment because the corks and felts look old and worn (a lot like me, btw). For my information, though, are new valves available for my horn? In googling around I found a shop named Dawkes Music there in the UK that sells new B&H/Besson 'Imperial' valves. Would these work for me? I asked someone there at Dawkes and they wanted to know my model number, but I don't know it. Is there a model number of my Imperial? I simply know it as an Imperial and nothing more.

    Thanks again for your excellent and kind help to me.
     
  4. 2nd tenor

    2nd tenor Well-Known Member

    There was a good thread on valve alignment about two years ago, I think that ds2014 was involved with it but can't be certain. The ideas gained gained from it helped me sort out two instruments that now play a lot better. Once you get your head around things it's surprising what improvement can be achieved by use of a simple probe, a 'ruler' and a few sums; replacement felts are available on-line and can be thinned with the help of fine sandpaper, etc.

    If you're in the USA then you might be able to get some gap filler valve oil - it's about double the thickness of ordinary valve oil - if not then try Windcraft Trombone slide oil. Tube net is a Tuba forum in the US that could give good advice, but be aware that Eb's are no longer popular in the US and three valve instruments aren't common either.

    If you're not certain about details to give to Dawkes then send them some photos of your instrument (including ones of the serial number and writing on the bell) and do the same for the various other repair shops that you have in mind. Mr Tuba (in Wales) also has a good reputation.

    I would be reluctant to buy new valves (if any are available) for an old instrument by mail order, it really needs to be taken to a repair shop who can better understand all the issues involved.
     
    Last edited: Jul 16, 2017
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  5. Tom-King

    Tom-King Well-Known Member

    Putting new pistons in old casings is a big no-no without additional work - it's not as simple as buying new ones and just dropping them in.

    How sure are you that the valves/casings are actually worn?
    If you depress a valve, then pull the associated slide out as far as sensibly possible and then press again, do you get a noise?

    If the valves are worn but not toast, you can often get away with simply using a thicker valve oil - Hetman 3 if you can get it, Yamaha "vintage" is good too.
     
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  6. Jack E

    Jack E Active Member

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  7. Anno Draconis

    Anno Draconis Well-Known Member

    Yes, they can be replated, most easily with copper, but it's a pain in the a$$ unless you know what you're doing. I'm going to attempt it in the near future with an old trumpet with very worn valves that I got off gumtree for £30 - I've taken the view that if I knacker it, it wasn't really playable anyway so no biggie. However this trumpet's valves have little metal valve guides near the shoulder of the piston that I'll have to take off first, probably with a soldering iron, and I'll need to manually lap them afterwards for which I'm going to make a 'home lapping' block in my workshop. I can't stress highly enough that I kind of expect to ruin the instrument, I'm just interested to see if it works. Copper plating requires the valves to be (a) spotless and grease free and (b) treated with an acid "pickle" beforehand, and I'll also need to rig up some sort of slow motor to keep the valve rotating in the plating bath to get an even coverage of copper.

    If yours is your only instrument, still playable OR worth more than a few pounds I would get a pro to look at it, not do it at home.

    It might also be worth trying valve oil designed for vintage instruments (Yamaha make some, it's a bit thicker than the normal stuff) or as a last resort before taking to a repairer, some stuff called "Break Free CLP" - it's from the US and used for cleaning guns and high precision engine parts. Again I would stress that I am trying these things out on an instrument that is mine, cheap and already pretty busted, so it's not a big issue for me if it causes problems. Your mileage may, of course, vary.
     
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  8. MWoj

    MWoj New Member

    Thank you, 2nd Tenor!
    Thank you, 2nd Tenor! I have 'gap filling' valve oil on order, and I should have it in a couple of days.
     
  9. MWoj

    MWoj New Member

    Thanks, Andrew! We have an excellent brass guy here and I'll have him look-over my horn. Good luck with plating experiment!
     
  10. MWoj

    MWoj New Member

    Thank you!
     
  11. MWoj

    MWoj New Member

    Thank you, Tom-King! I do get a slight 'pop' when I test the compression of most of the valves. I'm hoping the horn just needs a good valve alignment and a valve oil with a higher viscosity.
     
  12. Jack E

    Jack E Active Member

    I'd be very interested to read how you get on with this, Andrew - I think it would easily deserve a thread of its own.

    With best regards,

    Jack
     

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