Monel vs Stainless Steel

Discussion in 'Trumpet Discussion' started by kctrumpeteer, Feb 16, 2011.

  1. Peter McNeill

    Peter McNeill Utimate User

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    Doesn't copper and steel create a galvanic reaction, like a current between the two. I think the choice of valve oil, and how to store without freezing the copper valves to the casing.

    Anyway an interesting thought, copper is so soft, you'd need a way to replate them often - so maybe no viable.

    BTW glorybe. Congrats, the oldest Zombie thread raised this year. 3 years was the previous, 4 years is a good effort.;-)
     
  2. Sethoflagos

    Sethoflagos Utimate User

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    A small point, but the anti-wear (I use this term loosely) characteristics of valves and casings are not determined directly by properties of the bulk metals they're made from, but by the interactions of their surfaces. And these surfaces are almost always made of something entirely different in nature. As a rule of thumb, those surfaces should be of substantially different hardness; not to preferentially wear the softer material, but to reduce the wear of both.

    Anyone who is really interested in the relevant mechanics and genuine, professionally conducted test results may find this summary interesting. Mainly concentrates on grades of stainless steel (there are more of these than most realise), but some useful tidbits on leaded brass, silicon bronze and nickel plate. A snippet on PTFE-loaded nickel plate was particularly intriguing....

    https://www.nickelinstitute.org/~/M...lingCharacteristicsofStainlessSteel_9006_.pdf

    And a quick rough-and-ready crib sheet:

    http://www.mitech.co.za/pdf/wear.pdf


    Bottom line is - lubricate every time, and the problem vanishes.
     
  3. MusicianOfTheNight

    MusicianOfTheNight Pianissimo User

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    As long as you use UltraPure oils, I think you'll be fine!ROFL
     
  4. Bflatman

    Bflatman Mezzo Forte User

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    My own experience is as follows

    With a soft and hard material interface where there is an abrasive present and a lubricant, for example, a wood surface rubbed against a metal with a coating of grease between them and grit present in the grease, the wood is not abraded, the metal is abraded. In other words the harder material is worn away and not the softer. This is not always the case but things do not always behave as expected.

    Tests where unlubricated materials are rubbed together are not appropriate for reaching conclusions about lubricated interfaces between materials such as valves in musical instruments. Unlubricated bearing surfaces in motor engines will fail in minutes where lubricated bearing surfaces will last for decades. As a general rule lubrication stops surfaces abrading.

    With regards to valves in musical instruments, my experience is limited to only a few examples of monel and stainless and therefore of questionable value.

    In my experience there is a significant difference between stainless steel valves and monel. The stainless valves are smooth and slick, and remain so with minimal oiling and maintenance. Not so monel.

    Monel easily last as long as stainless, I have a 96 year old trumpet with monel valves and the valves are as good today as the day it was built, however in my experience they require much more attention than stainless. Residues built up on the surface of the valves swiftly and these residues must be removed or a hard layer builds up and this hard layer rejects the lubricating oil and binds on the chamber wall and leads to sticking. I have no idea why the monel valves build up this dirt layer and stainless does not, it is illogical to me but none the less happens so I report it here and invite comments about it.

    Once the residue is removed the monel valve runs as sweetly as any stainless valve.

    Both my stainless valves and my monel valves have been examined independently by other brass players and they have concluded that both the monel valves and the stainless valves they examined were in excellent condition.

    I have noted that other members in other threads have reported that their older valves on older instruments stick a lot, I question whether this could be due to the same issue I am facing, where monel valves accumulate dirt swiftly and binding and sticking is the result.

    This perhaps could be due to the mix of the monel itself which may vary between manufacturers, this seems tenuous in the extreme, or more likely it may be the valve oil I am using. This dirt build up has happened since moving back to using Blue Juice and more recently Herco.

    I would welcome members comments on their experience with valve oils and dirt build up, and in particular dirt build up with monel and stainless valves. I suspect there is some other factor at work that would explain this behavior but so far I have drawn a blank.
     
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  5. coolerdave

    coolerdave Utimate User

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    please get back to me on that
    only 44 years to go
     
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  6. Franklin D

    Franklin D Forte User

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    Hmmm, the best valves I know are in no specific order Bauerfeind (stainless steel I think), Getzen (nickel plated) and Henri Selmer (monel I suppose), so?
     
  7. OldSchoolEuph

    OldSchoolEuph Mezzo Piano User

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    I'm personally a fan of nickel. Long track record as a proven technology, and the easiest to replace/build out as the valves wear.

    Stainless seems to be the most durable with the least maintenance as found in most horns out there - but all you have to do is buy a set of wallmart "stainless" silverware and get it near hot water with lemon (ie: a dishwasher with standard detergent) and it will be a rusty mess because of the lack of nickel in the so-called stainless. So the durability of stainless valves could vary if the manufacturer goes cheap on the metal.

    Monel likewise is variable. I have seen excellent monel valves that work, and resist crud, every bit as well as nickel plated. And they are, by definition, harder and less prone to damage. However, if you have experienced Jupiter monel valves, then you know that this is not always the case. They had (perhaps still have, my last affected sample was from 2010) an issue with micro-porosity in the monel. When the sleeve of the piston is machined to its final dimension (and Jupiter valves are turned to a super-tight clearance against the equally precision-honed casings), the tiny pockets (you can't see these) in the metal are opened, and scrape the walls of the casing, filling in with brass. This appears as a dark stain on the piston. Since brass-on-brass leads to occlusion in a wet environment (it only takes the least bit of corrosion to rust brass wall and brass patch together), the valves stick like crazy. Jupiter was sending free replacement pistons if you called them back in 2010. Jupiter is not the only company to have trouble with monel like this.
     
  8. glorybe

    glorybe Piano User

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  9. MJ

    MJ Administrator Staff Member

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    What does Monette use these days. I know they make their own based on the videos I have seen.
     
  10. glorybe

    glorybe Piano User

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    King instruments made a very big deal of nickel plating over a nickel core as being superior. They did empirical testing by hooking a trumpet to a machine that depressed the valves endlessly and nickel over nickel did better than any other system. It is interesting in that nickel plating does behave differently than a normal nickel surface. I do believe that modern plastics may well surpass metals for valve construction in the near future.
     

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