problems with silver oxidation under Reunion Blues leather Valve Guard

Discussion in 'Trumpet Discussion' started by zetka, Sep 17, 2011.

  1. SteveRicks

    SteveRicks Fortissimo User

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    Aug 15, 2009
    Alabama
    Brekelefuw has hit it on the head. Outgasing is likely your problem. Lay the guard out in the direct sun for a number of days and see if it improves.

    On another note- while there are a number of good valve guards out there, you might want to look at Legacy valve guards. I have a number of them on my horns and they are doing well. Guards don't cost and arm or leg either -made from some stuff somewhat similar to what divers suites are made.

    On the aluminum foil method -I have been using the method for the last few years but haven't been overly happy at the results. Does anyone think using distilled water might help? Also, on the electrolysis -maybe using a 9 volt battery -where to positive and negative go (backwards and you reserve the process, right?)
     
  2. laurie

    laurie Pianissimo User

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    Jan 17, 2005
    Australia
    The level of tarnish on your horn indicates that the guard was made from acid tanned leather. That level of rapid,heavy tarnishing would have nothing to do with body sweat or acids,it just far to heavy for that.
    Its vital that hand guards be made with vegetable tanned leather only. I have a friend in the leather business who made some guards for me, we found out the hard way which leathers should/should not be used...
    Laurie
     
  3. zetka

    zetka New Friend

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    May 15, 2010
    Prague, heart of Europe
    I am the same opinion, as you and the people before said, it seems that they really did not use proper material for this purpose. On the guard box there is written "made in China" , so nobody knows. I try to ask Reunion about their opinion, maybe they reclaim it or at least take care about such thing.
    Thanks again all for reading and contributions to discussion.
    Zetka.
     
  4. ComeBackKid

    ComeBackKid Fortissimo User

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    May 11, 2009
    Yorba Linda, CA
    Steve,
    The only time I have had less than great results was when I tried it on some old silver-plated pewter and the silver was worn off in spots. On silver trumpets I have never seen it fail. What do you see that is less than satisfactory? If you try a silver polish or chemical cloth, does that make the silver shine better? It seems that something else is involved in this.

    I don't know that the battery technique would help but if you want to experiment, connect the negative to the aluminum foil and the positive to the trumpet (the electrons flow from negative to positive) - refer to Rowuks notes - post #6.
     
    Last edited: Sep 21, 2011
  5. zetka

    zetka New Friend

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    May 15, 2010
    Prague, heart of Europe
    Maybe my own comment to that.
    Just when I read it, I tried it. I use my wife's small plastic bath for wash (please do not tell her!!) and a small piece of aluminum foil 10cm x 10cm. A really small amount of kitchen soda (maybe 5g/5l). We have "hot water" from pipes only 50°C. In this configuration it did not work at all.
    After few test I began to be more and more cruel, added kitchen salt (50g/5l), I used more aluminum foil, finally the trumpet was practically wrapped around with it and added few litres of boiling water from the pot. In this final case after a 30minutes I saw finally some result of dissolving the black area, maybe the discoloration on the vents go to 20% of the original, but still visible.
    On some pieces of the aluminum foil I saw a small holes through, so really some reaction went through, but I did not seen the aluminum oxide or other product in the bath, so I do not know where it disappeared.
    There is question, if the electric touching of both objects is necessary or not, to have the electrochemical cell..

    Few years in the advertisement there was a "miraculous" metallic board, I think it was the same principle, but for jewelery and so on. I think that trumpet has a wide area and the density of the area current must be significantly higher.

    I would like to know, which temperature (at least estimation) used the others when they encounter good results of this method. I suppose that really high temperature close to boiling is needed, this is crucial....

    Zetka.
     
  6. ComeBackKid

    ComeBackKid Fortissimo User

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    May 11, 2009
    Yorba Linda, CA
    If you refer to the notes quoted by Rowuk in post #6, there are two key points mentioned that speed up the reaction - water temperature and salt concentration. I and sure that the amount of aluminum foil is also a contributor. When I do it, I use a large sheet (25 cm x 50 cm), a lot of salt (1 cup) and boiling water taken directly from the stove and poured into the tub. With that approach, results generally happen in a few minutes. I have 4 large pots which I fill with water and boil them all at the same time so that the trumpet is nearly completely covered with boiling water right at the start. The construction and plating operations that were used to create the trumpet were done in far more harsh conditions than boiling water so this will not hurt the trumpet at all.

    Depending on the amount of tarnish on the trumpet, you may not see a large concentration of aluminum oxide on the foil. It will be spread out and won't always turn it very dark.

    Based on the article quoted by Rowuk, it does not appear that contact is required. Ion transfer will happen through the water. I have always placed the trumpet on the foil but it would be an interesting experiment to try it without the contact.


    I hope this helps.
     
    Last edited: Sep 21, 2011

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