There are all kinds of things that can contribute to metal (I'll call it failure) in a horn. Brass or nickel silver can be softened, made more malleable or flexible, by heating to the annealing temperature which is pretty darn hot. Once it's cooled down from that, it can be bent, hammered, spun, or what have you without breaking or splitting. The bending, hammering, etc. though, will have the effect of hardening the brass, and past a certain amount of "working" the metal, it will be difficult to do any more reforming of the metal or it may split. Then you have to soften it again by annealing to work it further. Manufacturers used to stress-relieve the brass parts after forming, by heating them to a temperature somewhat less than the annealing point. If that isn't done, the metal tends to be more brittle and prone to cracking and getting red rot. I suspect, from some horns I've seen, that some manufacturers are neglecting the stress relief operation to save money. There are a limited number of things that a player can do to cause metal failure. Don't clean the horn and you'll get red rot, especially in the leadpipe, eventually you'll have small holes. You may be able to mechanically wear through localized spots from handling, or chemically eat holes if you have a lot of acid in your sweat. All fixable by replacing or patching parts. The only catastrophic damage I can think of, I've seen on a few horns that were stored in a very wet environment for a long time. There's a certain look to them that just makes you say "uh oh". The metal becomes very brittle and weak and you just have to look at it sideways for it to crack and split. It has to be a pretty radically wet environment to cause that. That can happen in a particular (whatever's the lowest) spot if the horn is stored for a long time with spit/water in it. The other problems that people complain about are pretty much all accomplished in the repair shop. Many times I've heard people say that their bell has thinned from age. That doesn't happen naturally though, at least not all over, just where your hand touches. What happens is repair shops burnish out dents, sometimes very aggresively which can stretch, thin and harden the brass if overdone. Then, especially if the horn is being relacquered, they sandpaper and then buff the bell. After all that, you have a thin, hard bell that often will "oil can" especially near the edge. After severe dents have been repaired over and over, that area can be super hard and brittle and very prone to cracking. Often a very deep and sharp dent should be annealed before repairing, especially if that area's already been worked a few times or the brass is folded sharply over itself. Otherwise you run the risk of splitting the brass. Sometimes a dented area is so hardened from repeated dent work, that the dent or wrinkle just won't budge at all until you anneal it. Relacquered horns are especially treacherous to work on because you can't tell what's been done to them before. They're often rough on the inside but sanded smooth on the outside, often with very thin spots and hard and brittle. A crack just waiting to happen. "Unrepaired" horns are generally very easy to work on, even if they have fairly severe dents, because they haven't been overworked. Then there's the whole chemical cleaning, acid dipping, sanding of tuning slide tubes etc. etc. It all takes a toll. Keep your horn clean, but no harsh chemicals, don't dent it up (gig bag), put it in the case at rehearsal break, don't do things that will make you have to go to the repair shop and it can be in great condition even a couple of hundred years from now.
- Steve Mumford _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
