Quote Originally Posted by rowuk View Post
I have questions about ultrasonic clean that have not been answered adequately. VW destroyed fuel injection nozzles with ultrasonic cleaning a while back. The process seemed to change the hardness of the metal.

I would think that a trumpet is MUCH more sensitive. Its special tone is the result of tension in the metal in special places, forged or milled braces with similar issues. I am not sure how aggressive the ultrasound baths are - and am pretty sure that the "average" tech rejoice more in the dirt removed rather in the sound changed (if they notice at all).

I know that Monette uses chem cleaning. Kind of tells me all that I need to know.
There are US machines built specifically for the instrument repair trade.
A horn that is being US cleaned typically doesn't need more than 2-3 minutes in the tank, and doesn't need to be submerged in hot water or harsh chemicals.
The frequencies used to clean are also much less powerful than ones that would be used to take build-up off of an automobile part.

I have never had an issue with US cleaning, and in regards to the red rot, any competent repair tech would know to inspect the horn for major red rot prior to US cleaning so they can isolate that spot from being cleaned, or clean the horn with chemicals or standard soap.