Dave Weiner's explanation is a good one if Hans' theory about a cheap relacquer job is correct. Still, Hans, if you have direct access to the engineers at Yamaha, they would appreciate a message about a potential problem as a courtesy. Although rare, I've been involved in problems that can't be seen until the product is in service for some time, and millions of dollars worth of product are in the warehouse.
If I were a Yamaha engineer and this problem were brought to my attention, I'd have that horn on a next day plane, unless I knew exactly what was going on. Put yourself in the same position. Even if it turns out to be a cheap relacquer job, if they're being sold as Yamaha production, you'd want to stop that practice real fast. Hans wrote on 5/7/2004, 12:08 PM: > First, Bill & Mike, we have to know, if you bought this horn as brand > new with no owner before, right. Is it a horn, which was owned before & > is just remade to look new & probably lacquered cheaply without getting > the lacquer burned in or baked in (lower temperature but longer time) ? > > I strongly doubt, if such failure might happen with a brand new Yamaha. > I have never heard about such lacquer behaviour from brand new Yamaha > horns. I have also inquired with the Yamaha engineers at Ginza, with > whom I am quite familiar due to my many visits there. They were really > shocked, when I asked them about "factory dust". The same will happen, > if I ask them about their lacquer process. > > But if the horn became lacquered later, well, then we have a problem > her, a quite frequent problem. A brass instrument must be degreased > completely before lacquering. This is done by ultrasonic device and/or > a tri-aethylene (hope I used the right name) bath. This process must be > done properly, the instrument dried after this, warmed up to the proper > temperature before lacquering, dried again, heated slowly in the oven, > then the lacquer must be baked in for some 90 min. at 120 degree (F 248) > & cooled down. There is no chance for any development of this rainbow > effect. > > Yes, there is a chance for the development of "Lackrose" (lacquer rose), > which are small brown places under the lacker at a soldering place where > two sheets of metal are attached one above the other & some solder > additive can squeeze out during the heating. But this is harmless even > it should be prevented. > > Mike�s problem with his horn should not be a manufacturing problem, but > rather a problem of cheap relacquering. Where did you buy that horn ?? > > It is not always the producer of the horns to be blamed. If people have > not learned the trade from bottom, they handle our instruments > improperly (re lacquering is one example !). It is not enough, to know > the physical rules, the chemistry & the acoustical rules of an > instrument, to become a repairman, there is much more to know which can > be acquired through apprenticeship with a very good master only. > > Mike, we wait for more news about your horn where you bought it (names > should be omitted). Was it brand new or used ? Was it lacquered or not ? > ============================================================ > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of william bamberg > Sent: Friday, May 07, 2004 7:09 PM > To: 'The Horn List' > Subject: RE: [Hornlist] Weird colors > > If Hans has never come across this, and I have never seen what you > describe, it is probably exceedingly rare or an unfamiliar failure due > to some brand new manufacturing method. The engineers at Yamaha will > want to know about this as soon as possible. > > Not having seen it, I'll hazard a guess based on your description that > it looks like oil on water. That rainbow effect is caused by the > dichroic nature of a thin film. dichroic simply means the color of the > reflected light varies in color depending on the angle of the light, > just the way a prism separates light. Since this is a property of a > very thin film, it implies that a very thin film is present in the light > > path. If you can't wipe it off, it must be under the lacquer. My guess > > is that the lacquer is separating from the metal and your cleaner is > forming a very thin film between the polished brass and the underside of > > the lacquer. If this is the case, the horn will have to be stripped and > > relacquered, or just stripped and left raw brass. Get your complaint in > > as soon as possible and demand an explanation. That way it will get > back to the engineers. There is no acceptable reason for this to > happen. Even if you used the wrong cleaner, there should have been a > clear notice not to use it. > > Hans wrote on 5/6/2004, 10:17 PM: > > > Blank metal, aggressive sweat, body cream or hand cream - no wonder, > > they will react some time. This is normal. So after a year or so, you > > should use a bit of metal polish, to polish this away. > > > > But if the horn turns bright red or deep purple or grass green or > even > > black in the bell, something might be wrong. > > ============================================================ > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On > Behalf > > Of [EMAIL PROTECTED] > > Sent: Friday, May 07, 2004 12:27 AM > > To: [EMAIL PROTECTED] > > Subject: [Hornlist] Weird colors > > > > Hey everyone, > > I just noticed something weird happening to my new 668NDII. It > > seems > > like the top layer is turning into those colors when oil is mixed > into > > water > > (you got your purple, yellow, green, maroon...) it seems like that is > on > > my > > horn, particularly on the bell. > > I never noticed it before, but I whiped it down completely > after > > every > > use, now I just wipe it down (completely) about once a week, and I > just > > noticed it about 2 days ago. I tried to see if I could whipe it off, > but > > no, it > > still had that oily water thing goin on. Anyone know what it could > be? > > > > Mike > > _______________________________________________ > > post: [EMAIL PROTECTED] > > set your options at > > > http://music.memphis.edu/mailman/options/horn/hans.pizka%40t-online.de > > > > > > _______________________________________________ > > post: [EMAIL PROTECTED] > > set your options at > > http://music.memphis.edu/mailman/options/horn/billbamberg%40aol.com > > > > > _______________________________________________ > post: [EMAIL PROTECTED] > set your options at > http://music.memphis.edu/mailman/options/horn/hans.pizka%40t-online.de > > > _______________________________________________ > post: [EMAIL PROTECTED] > set your options at > http://music.memphis.edu/mailman/options/horn/billbamberg%40aol.com > _______________________________________________ post: [EMAIL PROTECTED] set your options at http://music.memphis.edu/mailman/options/horn/archive%40jab.org
