The old soft lacquer easily caused pitting. I had a mid '40s King horn, the one with the upside-down change valve. Over 50 years it developed a bad case of brass pox in the bell. The depth of the pits were at least half the thickness of the metal. By the way, the pitting process is electrolytic, not Electrical Discharge Machining (EDM). There's a big difference. No arcs.
This brings up a question: What's the best way to preserve the metal? If you leave the lacquer on, you get pitting. If you remove the lacquer, you get tarnishing, and polishing removes metal. If you relacquer, a lot of metal is removed in polishing before lacquering. My guess for nickel silver would be to take the lacquer off and let it develop the funky grey patina. How about brass? Herb Foster --- Robert Osmun <[EMAIL PROTECTED]> wrote: > ... > Pitting on Conn 8D's: The pitting commonly seen on 8D's has nothing to do > with annealing. It's caused by an electrolytic process set up by the > difference in conductivity between the very hard acrylic finish used by Conn > and the underlying metal. As perspiration collects id pores and nicks in the > finish microscopic arcs remove metal just as an EDM machine does. The > hardness of the finish prolongs this process and creates deep pits. > Instruments with softer lacquer are much less prone to this problem because > the lacquer wears away before serious damage is done. > > Bob Osmun > www.osmun.com > __________________________________ Do you Yahoo!? The New Yahoo! Shopping - with improved product search http://shopping.yahoo.com _______________________________________________ post: [EMAIL PROTECTED] set your options at http://music.memphis.edu/mailman/options/horn/archive%40jab.org
