Black Brass

Discussion in 'Trumpet Discussion' started by Lupis, May 15, 2010.

  1. Lupis

    Lupis New Friend

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    [​IMG] So…. Today I just tried arm and hammer super washing soda aluminum foil cleaning, and it turned the brass on my silver plated strad black. I used a cup of the solution with 5-5.5 gallons of hot water (5 quarts boiled, the rest approx 110°F). I left it there for 3-4 hours and the water was still somewhat warm. As I took off the foil I was very nervous seeing black on the exposed brass and a film coating on almost the entire instrument, and a rainbow color on some of the outside silver (photo below). I rinsed off and soaped it in warm water and scrubbed some to most of the black off. I’m going to try to polish it out with Hagerty’s silver polish.

    What did this happen? Should I have soaped it first? Did I use too much of the washing soda? Are the rainbow areas there because the instrument got too hot? Has anyone had this happen to them? I don’t know if I will do this again, but need advice on this issue. Please respond immediately if you have any knowledge on this. Thank you. The link is
    [​IMG]black brass picture by wolf_lupis - Photobucket
     
    Last edited: May 15, 2010
  2. a marching trumpet

    a marching trumpet Mezzo Piano User

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    I can't see the picture, but on mon I can go ask my chemistry teacher about that if you'd like? He used to work in professional labs doing something till the company got bought out and shipped over seas, I think, and he's very very good at everything chemistry.
     
  3. Lupis

    Lupis New Friend

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    [​IMG]
     
    Last edited: May 16, 2010
  4. borge705

    borge705 Pianissimo User

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    I have only done my horn once but have used the method on other silverware a number of times. Your proportions are OK. I normally start with hot tap water (just too hot to touch) and only leave it in the solution for about an hour. By then, the foil is black and broken down. I'm wondering if you've left it in too long and the horn has simply become stained by the blackened water. How tarnished was your horn before you started? And what condition was the foil in when you removed it afterward?
     
    Last edited: May 15, 2010
  5. cmg

    cmg Pianissimo User

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    Arm and Hammer Super Washing Soda IS NOT Baking Soda. It is a detergent booster and contains other chemicals than sodium bicarbonate. I would read the box or contact Arm And Hammer to find out what other chemicals it contains in order to determine exactly what chemical reaction occurred on the silver of your trumpet. The trick, then, is to determine if there is an easy reverse chemical reaction to get your silver back to normal.
     
  6. ComeBackKid

    ComeBackKid Fortissimo User

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    The picture works for me. In fact, I sort of like the 'rainbow' effect (just kidding). Based on your description, it sounds like you mixed the brass/lacquer removing method and the silver tarnish-removing method together. The silver method uses either sodium chloride (salt) or sodium bicarbonate (soda). It is not necessary to wrap the trumpet in foil - just put a sheet in the bottom of a non-metallic tub along with the salt water. Also, I normally do not leave the trumpet in the water that long although I can't imagine that was the cause. I have done this many times and have never had 'the rainbow' happen - so, it is still a puzzle.
     
  7. Lupis

    Lupis New Friend

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    I actually did not mean to leave it in there that long but my friend stopped by my house with 6 canoes right after I had put it in the bath. He assured me we would be gone a couple of hours but like I said we were gone 3-4 hours.
    I based all of my procedure off of an older polishing post. They assured me that baking soda (sodium bicarbonate) and salt (sodium chloride) we best be left to baking bread and salting steaks.
    My horn was tarnished enough so that removing it with a polishing cloth was somewhat hard and wasn't doing much good. So, into the bath it went. Last night I tried to polish (Hagerty's) the film and rainbow out, and it was only an ok job and am going to finish polishing later today.
     
    Last edited: May 16, 2010
  8. ChopsGone

    ChopsGone Forte User

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    I'd have to dig up my box of it to be sure, but IIRC Arm & Hammer Super Washing Soda is plain old sodium carbonate - or, as they like to advertise it, a natural product. Here's a quote from the company's web site:

    "Silver, Copper, Gold Pieces
    Super Washing Soda can be used with special cleaning plates such as QWICKSILVER®, SilverLion and Speedy Plate to remove tarnish from silver, silver plate, jewelry, gold, copper, bronze, stainless steel and most brass"

    I haven't tried any of the "special cleaning plates", but otherwise I agree. It's also just the thing if you're doing any electrolytic cleaning of iron or steel (usually done with a sacrificial anode of scrap stainless steel).
     
  9. ComeBackKid

    ComeBackKid Fortissimo User

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    If the trumpet was really that badly tarnished, the result you obtained was beneficial in that most of the really bad tarnish is gone. Perhaps it just needs another treatment with the salt water and a sheet of foil in the bottom of the tub. I would try this before resorting to polish which may remove some of the silver plate (the black residue on the cloth).

    As you stated, the "Super Washing Soda" is Sodium Carbonate which works better on copper/brass while Sodium Bicarbonate or Sodium Chloride works better on silver plate. The "Speedy Plate" is the anode and in this case, it is simply Aluminum foil. This is why we have the "Salt Water and Aluminum Foil Bath" technique that is widely recommended.
     
    Last edited: May 16, 2010
  10. Lupis

    Lupis New Friend

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    So is salt better than washing soda in this case?
     

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