Posted by Lee Stofer on October 13, 2002 at 16:52:18:
In Reply to: chemically cleaned??? posted by david on October 09, 2002 at 10:11:25:
David,
When a reputable business says that an instrument will be chemically cleaned, that should mean that a multi-stage process is used to render your instrument as clean as new (or better). The instument will be disassembled, washed, and have additional de-greasing if necessary. Acids will not work properly if there is valve oil/slide grease, etc., on the parts. When the parts have been thoroughly washed, they should be immersed in a sulfamic acid solution, or another de-limer/de-scaler solution, to remove the calcification. When you see hard green or white deposits in your horn, particularly in slides and on rotors, that is calcification. After removing the parts from the de-limer solution, I wash them again and inspect each part. If there are any white or green bumps left, I will generally take a triangular scraper and remove them, then dip the part(s) in the solution again, then wash them again. If the parts look very good, then that is all that is necessary. For badly discolored and corroded parts, I will briefly dip them (about 5 seconds) in the bright dip tank. This renders the brass bright yellow again, removing bown and most if not all of the pink color. It will not remove calcification, so that is the reason I use stages of cleaning. At the beginning of the cleaning, if the slides have some sort of thick, nasty grease on them, I have a citrus solvent de-greaser that cuts that stuff fast, and makes the subsequent washing much faster and thorough.
chemical-cleaning a silver-plated instrument is a bit more difficult than a lacquered one, as some of the chemicals really discolor the silver, necessitating a hand- repolishing of the entire instrument, or whatever parts that were dipped. The cost of chemically cleaning an instrument at my shop depends upon three things - condition, conditio, and condition. If your instrument requires two hours work, it won't be as expensive as when I spend 6 hours getting an instrument right. Wherever you get your horn worked on, don't be afraid to ask questions.
Lee Stofer