Having cleaned many thousands of horns both via acid baths, and ultrasonics I can say that I am thoroughly in the ultrasonic camp for many reasons. Also, I want to correct some misperceptions about the ultrasonics method that I've read here as well.
In order for a horn to be properly cleaned it has to be completely degreased, and an acid bath will only work if there is no grease or oil left on the surface of the dirty areas where as an ultrasonic cleaner removes all foreign material at once. (there's a video of a horn being cleaned on my website: http://poperepair.com/info/repairs ) As for the safety of the horn - when used correctly an ultrasonic cleaner will never make 'holes' in an instrument. Often times, when a horn has red rot, the ultrasonic will clean the instrument so thoroughly that the pinholes from the red rot are no longer clogged - but beyond that, there are controls on the machine that allow the technician to use different power levels for each situation - even on full power I can put in a piece of thin aluminum foil without any harm. Modern ultrasonic cleaners which were made specifically for instrument cleaning have been adjusted so that they do not damage the instrument. Every major manufacturer (a nd ALL the German makers) use ultrasonic machines - and have stopped using acid baths because they are SAFE for the horn, and do a better job. The only issues I've ever had was with the removal of some lacquer on a very few horns - and this is typically due to lacquer that is either not correctly applied, or has been through many temperature changes. A few more thiings to be aware of with Acid baths are 1. If the technician does not neutralize the metals of the horn after a cleaning it will be MORE likely to end up with red rot (dezincification), since acid is corrosive and leaves the brass in a non-neutral state. 2. Acid baths use the same solution over and over and over - whereas an ultrasonic machine filters all the water 3 Ultrasonic machines are far 'greener' (better for the environment while doing a better job!). The only waste from an ultrasonic machine is water with dishwashing detergent, and a small amount of an additive which lessens the surface tension of the water to allow it to clean better. (ultrasonic machines are used by dentists to clean teeth!) 4. How long should a technician leave a horn in an acid bath? There really isn't any set answer to this, and the best thing one can do is 'guess'. Since the ultrasonic medium is basically water and soap there is no such worry if it should be washed for 2, 3, or 4 minutes. As a repair tech, I am happy that I no longer have to breathe in those fumes all day (which also rust all the metal in the shop!). Ultrasonic machines are VERY expensive - but they can't be matched in the job they do. I would welcome anyone to bring over an instrument which was recently acid washed - and watch it go through the ultasonic cleaner just to see what the acid bath missed! (first person to bring over a just cleaned acid bath horn will get a free cleaning by me so that I can video it and put it up on the web for all to see!). Sincerely Ken Pope Pope Instrument Repair 80 Wenham Street Jamaica Plain (Boston), MA 02130 617-522-0532 http://www.poperepair.com _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
