Damage on a Vincent Bach Stradivarius Model 42

[spinakis]

Hello,

I bought on ebay a Model 42 Tenor Trombone wirh an immaculate bell-part and a completely damaged slide-part. The lack has red dots. It‘s playing wonderful, so I wonder what may have harmed the instrument and if this might be a potential danger for other instruments around in the house.

Thank you for suggestions, Matthias

[UATrombone]

Hello,

I bought on ebay a Model 42 Tenor Trombone wirh an immaculate bell-part and a completely damaged slide-part. The lack has red dots. It‘s playing wonderful, so I wonder what may have harmed the instrument and if this might be a potential danger for other instruments around in the house.

Thank you for suggestions, Matthias

It's not a virus, so, don't worry about your other instruments.
Also, it's not typical place for red rot, which usually grows from inside.
But, I could be wrong in last statement...

[MrHCinDE]

To me it looks like it could well be red rot („Zinkfraß“) in German. Maybe take to your local technician to check.

If it is red rot, at some point some holes may appear, hard to predict how it will develop. There seems to be quite a bit of it and it looks to be on the upper and lower slide near the oversleeves. If you otherwise like the horn it may be worth considering getting the outer slide tubes replaced at some point.

Did the seller show it on the photos or otherwise mention in the listing? It‘s hard to imagine they wouldn’t have noticed it. Did you ask the seller to explain?

[AtomicClock]

I've seen lacquer wear on the slide tubes because that's where the player held the horn while counting rests. Red rot in the bare spots may be due to the individual player's body chemistry. But I'm no expert.

[Burgerbob]

Just oxidation under lacquer failures.

[Doug Elliott]

Just oxidation under lacquer failures.

Yes, it's lacquer failure, probably stored in a wet or salty enviroment. I don't think that happens in ideal conditions.

[tbonesullivan]

What era is that horn from? Bach, if I recall, was one of the last to abandon Nitrocellulose lacquer on their horns, which over time can "check" and develop small holes in it in the right condition. This is the same reason why hot water can make older Bach lacquer literally fall off. These little holes could lead to what you are seeing. You could take a gentle metal polish to those areas, and see if the marks go away. If they do, it's just surface oxidation.

[spinakis]

Thank you for explaining it to me. If there is no danger of spreading to the bell section or to other instruments i'm fine with it. I saw the dots, when I bought it, so no blame on the seller.

[spinakis]

What era is that horn from? Bach, if I recall, was one of the last to abandon Nitrocellulose lacquer on their horns, which over time can "check" and develop small holes in it in the right condition. This is the same reason why hot water can make older Bach lacquer literally fall off. These little holes could lead to what you are seeing. You could take a gentle metal polish to those areas, and see if the marks go away. If they do, it's just surface oxidation.

The serial is 137188, so I guess it is late 90's

[UATrombone]

Blood, sweat and tears (and, maybe saliva) from horn's "student" years.
Could be body "acidity" of previous owner.
You can go to a tech, check it and, if there are no issues - ask him to polish outers and relaquer them (if you wish).

[BGuttman]

Another source of this kind of problem is the water spray used. Some waters are pretty acidic and will attack the lacquer and eventually the brass underneath. The transition to waterless lubes has made this kind of problem extremely rare.

[hornbuilder]

There are a couple of spots that may potentially red rot.

Notice the little white center spot, that looks like a pimple. If you want to confirm, polish the spot with some non-ammonia brass polish. If the pink discoloration goes away, then it is not red rot. If the pink cannot be polished away, and a red dot with a black spot in the center remains, then it is red rot. Yes, this will compromise the lacquer, but it is the only way to say for sure.

[spinakis]

There are a couple of spots that may potentially red rot.

Notice the little white center spot, that looks like a pimple. If you want to confirm, polish the spot with some non-ammonia brass polish. If the pink discoloration goes away, then it is not red rot. If the pink cannot be polished away, and a red dot with a black spot in the center remains, then it is red rot. Yes, this will compromise the lacquer, but it is the only way to say for sure.

Thank you. With Yamaha Silver Polish I did polish for some seconds and got the red color removed. See the before and after. So what is this red stuff, if it is not red rot?

[chouston3]

There are a couple of spots that may potentially red rot.

Notice the little white center spot, that looks like a pimple. If you want to confirm, polish the spot with some non-ammonia brass polish. If the pink discoloration goes away, then it is not red rot. If the pink cannot be polished away, and a red dot with a black spot in the center remains, then it is red rot. Yes, this will compromise the lacquer, but it is the only way to say for sure.

What kind of non ammonia brass polish do you use?

[NotSkilledHere]

red is one of the color of brass oxidizing so it's normal. You can actually somewhat control what color it patinas/oxidizes in some various methods.

[UATrombone]

Thank you. With Yamaha Silver Polish I did polish for some seconds and got the red color removed. See the before and after. So what is this red stuff, if it is not red rot?

I suppose that Brass polish will do this even better.
As was mentioned different chemicals/environment etc. may change color of different brass alloys in different ways.
It could be red, rose, green black and so on.

[hornbuilder]

Hope's brass polish is a non-ammonia product.

[chouston3]

Thank you. I will get rid of my stash of Goddards brass polish.

[hornbuilder]

Just checked the ingredients of Goddard. It does contain ammonium hydroxide.

[UATrombone]

What about Yamaha metal polish?
I'm using it for many years but can't find its list of ingredients...

[chouston3]

I originally got the idea of using brass polish on my slides from The Slide Dr. I used wrights back in the day. When I started playing again, I hunted all over town for it but could not find it. Goddard's seemed like a good substitute and it does work. However, I did not know about the ammonia problem. I will switch to hopes. I like to shine up my tuning slides and leadpipes. Next time I go by a thrift shop, I will buy a sheet to polish the inside of my outer slide. I am always horrified by how black the sheets get.

[AtomicClock]

However, I did not know about the ammonia problem.

What ammonia problem? All hornbuilder said is it doesn't identify red rot.

[hornbuilder]

Ammonia induces micro stress fractures in brass. I know Conn-Selmer will not allow "any" chemical in their plant that includes ammonia in its ingredients

[Posaunus]

Ammonia induces micro stress fractures in brass. I know Conn-Selmer will not allow "any" chemical in their plant that includes ammonia in its ingredients

This is the #1 reason to never let ammonia-containing glass cleaner (e.g. Windex) near your brass instruments (or your brass door & window hardware, lamps, furniture knobs, ... , anything made of brass).
Also not friendly to many lacquers!

[tbonesullivan]

Ammonia induces micro stress fractures in brass. I know Conn-Selmer will not allow "any" chemical in their plant that includes ammonia in its ingredients

Oh wow, that I was not aware of. Don't most brass polishes contain ammonia? I know that Wright's Brass polish, once recommended by the Slide Doctor for cleaning the inside of outer slides, definitely does. They now recommend Goddard's brass polish, but that also contains ammonia, per the MSDS.

[chouston3]

I am surprised I didn't hear about this sooner. I have used windex to polish the lacquer on my instrument in the past. I used Wrights brass polish for years on my Bach 42.

I am switching to ammonia free cleaners now but I am curious as to how much damage I have done.

[atopper333]

Well, that’s definitely an eye opener…looks like I will be avoiding the Never-Dull from now on out!

[ithinknot]

Hope's brass polish is a non-ammonia product.

But they're using 2-amino-2-methyl-1-propanol instead in the same role... read an MSDS for that. Basically, any of the "instant"-acting (not purely mechanical) liquid polishes are going to be a problem used too often or left unflushed for too long.

[hornbuilder]

Hmmm...

Thanks for that.

[BGuttman]

But 2-amino-2-methyl-1-propanol is a much bigger molecule and less able to penetrate into the brass matrix to cause the cracking; which is probably due to the amino groups.

[tbonesullivan]

Well, that’s definitely an eye opener…looks like I will be avoiding the Never-Dull from now on out!

Depends on the "Version" I believe. 'the Original' should just be wadding and petroleum distillates. I think some of the "Eagle one" versions contain some ammonia. I'll have to check mine when I get to work.

[Posaunus]

My take: Whatever you use should be thoroughly rinsed off with purified water and thoroughly dried.
Contact time matters. Residual moisture can be harmful. Keep everything clean and dry.

[atopper333]

Well, that’s definitely an eye opener…looks like I will be avoiding the Never-Dull from now on out!

Depends on the "Version" I believe. 'the Original' should just be wadding and petroleum distillates. I think some of the "Eagle one" versions contain some ammonia. I'll have to check mine when I get to work.

Yeah, the stuff I have now is the newer ‘Eagle’ version. To me, at least, it has a slightly different ‘smell’ to it. I haven’t seen the original out where I’m at in some time…