Posted by Daniel C. Oberloh on February 02, 2001 at 01:32:10:
In Reply to: Re: Re: Re: cryogenic tuba freezing posted by Rick Denney on January 31, 2001 at 22:45:21:
Over the years I have pondered the reasoning of putting horns in the deep freeze with many of my comrades in the metals and music bizz. I was once asked by a trombone playing metallurgist "what are horns and there parts made of?" Well, I told him: yellow-brass, nickelsilver, gold-brass, red-brass, monel, bronze, These are all copper alloys with percentages of other elements such as zinc,nickel and tin. other metals like silver, gold, aluminum are used. and lets not forget the solder that is made up of lead, tin, antimony and other trace elements. I then realized from my answer that these alloys and elements all have different rates of expansion and contraction! This got me thinking that it is possibly a mechanical release of stress based on the metal stretching or dare I say breaking! within itself at the molecular level that is causing the change. Shrinkage most likely would be having its greatest effects at the solder joints and I would imagine if that is the case, there will be a few horns out there with solder joints failing way before there time. worst case failure would be at the connection between any two rotor casings, $$$$$ and messey! I think I will pass on the deep freeze and keep all my horns the way they sound best "warmed up".
Junk food for thought.
Daniel C. Oberloh esq.
Repair technician to the stars. (Floyd and Emma Star of Duvall Wa.)