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I do not have this case in any of my saxes but while browsing on ebay I saw a handful of vintage and not-so-vintage saxes with brown-reddish tinges on the surface. All my searches showed how it eats the brass alloy (w/ zinc) and there is no way to stop it once it begins eating up on the brass. Looks like those guys either neglect or do not know how to take care of their instruments. I didn't know what it is until I further made web searches. Gordon, your comments, suggestions, please. Or anyone? :?
 

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I think it is more of a function of the make up of the brass allow in question more than improper care. I have a vintage Yani that came to me with some red rot. I have a 1950's aristocrat alto that is basically bare brass and shows no evidence of red rot neither does my aristocrat tenor which appears to have lived at a school at some point.

I've also read that it would take a very long time for red rot to do significant damage. That may or may not be correct - I look forward to the thoughts of some of our well respected techs as well.
 

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Red rot does seem to have to do with the newer brall alloys. It is the result of dezincification(spelling?) , but really seems to show up more on newer horns, in the brass family, as well as saxophones. It seems to attack smaller tubing the most, which makes me believe the saliva must be the culprit. I have no knowledge of any way to stop it, besides replacing the metal of the affected area, or patching over the area. It seems that preventive measures are the best bet overall. Wipe out the neck after playing, maybe even get a extra swab and pull through a wet swab, with some water on it, then dry the neck with another swab, just to be extra carefull. Thankfully most of the newer horns still have necks in production.
 

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I agree with Saxdaddy.

But the dezincification process needs some agent to make the chemical reaction happen. Perhaps acid, enzymes, other chemicals, or even bacteria in saliva or perspiration, which is much more corrosive for some people than others. At least a few of my customers blow nose liquids &/or saliva over the OUTSIDE of their horns while playing.

Surely, if the corrosive agent no longer has access to the brass surface, then the corrosion will not continue.

A good case for a decent lacquer, yet players seem hell-bent on removing it!

And sure, it may depend on the particular brass alloy used.
 

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I just bought an old bari with a fair amount of red rust around the top end. This is not a valuable collector horn, so would a brass polishing compound e.g. Brasso, remove the tarnish to the point where wax, or a light touch up with lacquer would protect it from further deterioration? I have no issues with resale value, etc, I just don't want it to look so bad, or get any worse.
 

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pfox, I don't know. I have not met enough of it to know. I don't know how superficial or deep this stuff can get. I'd try Brasso. If you do any sealing, be careful, because sealing can seal in the agent that causes the deterioration.
 

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Collinite metal wax takes the redrot off. Available from Caswell Electroplating www.caswellplating.com

3M Tarni-shield For Brass also works. Available from Ferrees.

Both of these products act as a one-step nonabrasive cleaner/sealer.
The Tarni-shield smells worse and you have to buy separate versions of Tarni-shield for brass and silver; where one bottle of Collinite is good for both types of surface.
 

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What trade or hobby is the Collinite usually used in - the website you gave is in the USA, I'd like to find an outlet for the stuff in the UK and wondered where I would start looking?
 

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That stuff may be able to polish the metal, and hopefully protect the metal as well, but it can't actually remove the red rot, unless it can replace the zinc that is missing, and somehow remix it with the copper that is still there. Make sure that if you try this, get the inside surface as well as the outside, since red rot starts off inside the tubing, and comes to the surface through the metal, many time you will see it under the lacquer.
 

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From some research:-
Dezincification selectively removes zinc from the alloy, leaving behind a porous, copper-rich structure that has little mechanical strength, exhibiting a white powdery substance or mineral stains on its exterior surface.
The cure is a specification that limits brass alloys to those containing no more than 15% zinc, or specification of proven dezincification-resistant yellow brass alloys.

You may find the use of this product helpful though I should omit the steel wool!

http://www.westernwooddoctor.com/metaldoctor.htm
 

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If dezincification is a significantly damaging process, then I would like to know if it is actually carried out by the muriatic or phosphoric acid baths used by many repairers for routine cleaning of brass instruments, especially the slide and valve instruments.

Some repairers do this annually to school instruments.

Others use ultrasonic cleaning, which I believe may dezincify also. After all, it quickly punches holes through aluminium foil.

I brought these issues up in a repairers' forum but disappointingly, little interest was shown. The same forum discusses the severe corrosion that occurs in valves of brass instruments. Hmmm!! A bit worrying?
 

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I would have to give that one a big NO. If this was the case, then it would be found all over the instrument, but it isn't. It tends to be most common in the smaller tubing, where direct contact with the spit, and condensation is the greatest.
 

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Perhaps it IS all over the non-lacquered/plated surfaces?
 

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Not really. You will see pitting, but not red rot. Don't get me wrong, it will show up anywhere, but it is most common, on smaller tubing, close to where the mouthpiece connects to the instrument, or areas where the condensation collects, like around water keys on brass horns or in the lead pipe, the necks of saxophones. Unless it is pink in color, its not red rot. And it seems to work from the inside out.
 

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What I am saying is that red rot does not SUDDENLY become visually apparent. It must have already developed to some degree BEFORE it is visually red, and its small beginnings may well be on any unprotected surface after acid treatment.

Just because something happening at a molecular level cannot be seen, does mean that it does not exist.
 

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And all I am saying is thatsince the entire inside of the instrument insn't lacquered, and the red rot shows up in instruments often only few years old, which also have been chem cleaned, that if it were from the acid, then it wouldn't show up in just the smaller tubing. The smaller diameter tubing isn't any thinner, yet it seems to get the red rot very quickly. The shop I am in services 5 stores, a rental fleet, and alot of walk ins, we also track all of out instruments with a computer, so If I look up the repair history on a horn, I can see what has happened before. This really helps one to see patterens, now you are right in saying that a chem clean could cause it, there is no doubt in my mind that it can, and does happen, but only if the job was substandard. Poor rinsing is the biggest mess up that could happen, then you have, too long in the bath, too strong of a bath, the failure to soak in some kind of nutralizing bath(for more than just a few seconds). Alot of things can go wrong, but I have seen plenty instrument with red rott, that have never had a chem clean, just alot of condensation. Who knows how strong of an acid might come from your mouth, as your breath collects on the walls of the neck, or lead pipe.
 

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It's my experience that red rot is associated with spittle ( which has a bit of hdrochloric acid in it's makeup as I recall) and it is interesting that my muriatic acid also contains Hydrochloric Acid. You also see a red surface corrosion on some older horns that I assumed came from the individuals perspiration with the understanding that everybodies metabolism is so different . For example look at how a small percentage of people have such a reaction with silver...sometimes just with the liplate of their flute or one hand and not the other. I have a clarinet in right now with the keywork covered with corriosion spots that would correspond quite nicely with the spray of spittle coming from the players mouth.
After many years of acid bathing I was getting frustrated by horns that came out of the bath, were rinsed/flushed and when dissembled for dentwork had a cosiderable amount of the green monster still present. I always attributed this to the fact I was bathing the horn in a bathtub of the same chemical (HCl acid) that caused the problem in the first place. This is why I switched to ultrasonic cleaning. I just took apart a tuba for some dentwork and it is amazingly clean.
 

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Whether it be hydrochloric or muriatic (sulphuric) or nitric or phosphoric, these are 'strong' (technical term) acids which attack zinc very fast. The moment you put zinc in these acids it starts fizzing , as the zinc chemically reacts and effectively dissolves. Copper is attacked more slowly. How much these acids attack zinc when the molecules of zinc are interspersed with copper molecules, I do not know.

The condensation from moist breath would be pretty pure water. However some players put significant saliva down (and even over - yuck!) their instruments.

I don't think there is sufficient acid in saliva to cause a problem. However there are enzymes, and who knows what they may do to metals.

I think the saliva reaction is probably not because of the saliva itself, but a similar action to what destroys teeth. Then bacteria in the saliva feed on nutrients in the saliva, producing acid waste products, which attack the metal, possibly with the assistance of the enzymes.

The more the surface of the metal is compromised at a microscopic level (INVISIBLE the naked eye) the more these bacteria are able to take up residence, just as they do in the plaque on teeth.

As you know, I highly suspect ultrasonic cleaners for providing a surface that is better for bacteria, acids, etc to collect, just as high pressure water blasting of concrete washes away cement, making the surface better for moulds and lichen to take purchase.
 

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Nice to read information on brass corrosion.

Saliva doesn't contain any acids as such , in fact,healthy saliva, is incredibly close to neutral PH.

I talked about that in a thread concerning mouthpieces. here an extract from that topic

milandro said:
......The saliva PH varies from very mild acid to very mild alkaline. .......In healthy individuals, saliva PH stays within range between 6,5 and 7,5. Hardly an aggressive chemical....
However red rot or other forms of corrosion of the brass happens, no doubt about that.

I have this Baritone where the brown stains are all on the outside of the tubing, the inside is in a pristine state, in fact, it is much better than most saxophones I ever owned.

So obviously condesation or saliva play no role, at least in this case, It should happen from inside out unless we postulate that someone has been licking his horn clean. I think that red rod is very often caused by a combination of condesantion and chemicals (gasses?) forming or present in the case or in the lacquer itself. This will explain how red rot is almost always on the outside of an instrument and almost never in the inside.

However, what to do about it? Do any of the repaires and restorers of the forum deal wit it successfully and how?
 
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