Sunday, March 27, 2011

What are our instruments made of? (part 1)





This is a more complicated topic than it seems, and it really does matter what kind of metal your instrument is composed of. Not all metals are created equally. Some are of inferior quality. Some metals change during the manufacturing process depending on how they are worked, annealed or handled. Because this is a Tuba/Sousaphone blog I am going to focus on Tuba and Sousaphone manufacturing and how each metal might effect the player. First, let us look at the composition of common metals used in brass instrument manufacturing.

METALS USED IN BRASS INSTRUMENT MANUFACTURING

  • Yellow Brass  --------------------------------- 70% Copper - 30% Zinc
  • Nickel Silver (or German Silver) -------- 70% Copper - 20% Zinc - 10% Nickel
  • Rose/Gold Brass ----------------------------  85% Copper - 15% Zinc
  • Red Brass ------------------------------------- 90% Copper - 10% Zinc
  • Monel------------------------------------------- 31.5% Copper - 66% Nickel - 2.5% Iron, Manganese and Silicon
  • Stainless Steel-------------------------------- 90% Iron - 10% Chromium 
source: http://www.co-bw.com/Articles%20The%20Metals%20Our%20Instruments%20are%20Made%20of.htm
VARIATIONS IN THE "COLOR" OF BRASS
 The pictures in order from top to bottom: Red Brass Cerveny, Yellow Brass Cerveny and a Gold Brass Mirafone. 


Once you see the composition of the metals, it is easy to see that as the copper content of the metal goes up the metal gets more and more red in color. The metal also changes in the way it plays (depending on the player and the player's aptitude). The answer you will get about the way one metal plays versus another may vary from player to player, so I will not attempt to define any concrete playing characteristics. 


In my opinion, the most important place the metal composition matters is in the mouth pipe. This is because of a common chemical reaction in brass instruments called dezincification or "red rot." 


Think of brass alloys as a woven mesh of copper and zinc. The acidity in your mouth will begin to corrode away the zinc, leaving only the copper behind rotting the pipe away from the inside out. The visual evidence of this on lacquered brass or raw brass instruments are pinkish red spots on the brass. The visual evidence of this on silver plating is blisters under the silver plate. Below is a picture of a Trumpet main tuning slide crook with red rot.
Here is how to avoid red rot in your musical instrument. According to www.BrassArts.com:


"You can help prevent it by reducing the acids you introduce into your instrument.  Avoid eating right before playing, and especially drinking acidic drinks such as coffee, tea, sodas, lemonade, and so forth.  Brush your teeth before playing if possible, or even simply rinse your mouth well before playing.  Empty the water out of your instrument right after playing and oil it before putting it away.  Periodically, remove the tuning slide and run a flexible cleaner, or snake, through the mouthpipe or leadpipe of your instrument, rinse the pipe with clean water, and let dry before reassembly.
Your technician can help, as well.  After a cleaning with any acidic solution your instrument should be acid-neutralized, rinsed thoroughly, and dried completely.  Further protection is offered by oiling critical parts.  Check with your technician to be sure that these protective steps are followed."


For Tuba players, you can get a snake that fits the bore of your horn, remove the first valve or rotor then snake the mouth pipe. Carefully rinse the mouth pipe and make sure the instrument is bone dry before you reassemble it. 

Other ways to prevent this are to have a mouth pipe installed that has a low zinc or non zinc alloy. The newer version of the King 2340/2341 Tuba has a detachable nickel-silver mouth pipe. Many new Tubas can be purchased with a nickel-silver mouth pipe. The red brass Cerveny above has a nickel-silver mouth pipe.

Next time...pistons and rotors


Links and resources:
What our instruments are made of 
About Red Rot at www.BrassArts.com

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