In a message dated 3/7/2004 1:53:26 PM Eastern Standard Time, [EMAIL PROTECTED] writes:
> Sorry, > But how can you tell if the horn has "factory dust" > left in? Are there > tell tale sings I would notice or something? No manufacturer could possibly survive sending out a significant number of instruments that are going to require factory warrantee service, or be obviously degraded, just from being played. I don't have specific first hand knowledge of particular manufacturers, but I can make pretty good guesses from having set up many similar manufacturing operations. Cleaning out lapping residue is a difficult shop operation. All this work would be completed before the horn is assembled. Since the parts are all the same, specific tools and procedures would be scrupulously developed and used, followed by rigid inspection. Likewise, contamination from assembly soldering would be closely controlled. The one place where problems could slip through would be in rework of finished instruments that don't pass final assembly. Rework of a sticky valve or leaky solder joint would undoubtedly contaminate the instrument and require re cleaning outside of the normal procedure. This is much harder to control because it falls outside standard procedure, and requires operator intelligence and diligence, rare qualities to be found at a factory wage. My inclination, as an inquisitive engineer, would be to disassemble the horn and personally clean and hand polish all the parts. That is the best inspection procedure I know for evaluating a used instrument. Short of that, I'd push clean white cloth through the bore looking for deposits. Look closely at what turns up, particularly look for particulate material. If there is anything that's going to cause serious damage, you're going to feel it when you operate the valves. If you feel grating, and you keep working the valves, chances are you're too stupid to benefit from these simple instructions. Take the valves apart and do a thorough cleaning. If you're unsure of your abilities, it's not difficult. If you post what you're attempting on the net, you'll have several knowledgeable people offering friendly help within minutes. In a pinch, you can do the whole job with a butter knife and a wooden spoon, as long as you pick a butter knife that fits the screws properly. The actual cleaning is done with a snake brush and cotton swabs and cloth or paper towels using dishwasing liquid and brasso to clean and polish. Chances are, you won't have to do any polishing, just soaking, scrubbing, and flushing. At worst, you might have to take all the parts to a technician to be reassembled, but you'll know you spent enough time to really get things clean. Save the dirty swabs with the original sludge, and the last clean swabs, to show the technician. They will tell him more detail than you can. Watch the reassembly so you can do it all next time.
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