My Tuba's turning blue!

[NickIngrþoe]

Hello TubeNet!

While this may be my first post, I've watching you all for ages

Anyway, I have a nice vintage (60s/70s im not sure - the serial has long since disappeared from existence),
Boosey and Hawkes EEb 4v compensating tuba, which I love dearly. As with any old tuba, it will show signs of age,
with imperfect lacquer - that's fine, I've been ignoring it for ages.

However it is unquestionably turning bluey green. Just today I gave it a full bath, and the blue has suddenly
expanded and affected most of the tuba! Like some kind of infection. Is this normal? It seems like quite
a strange way for a tuba to turn old, and why the sudden explosion in blueness? Something to do with wetness?

I have more pictures if wanted but it's only letting my upload 3 for now...

Welcome any comments or suggestions of what I should do to combat this very colourful invasion.

Cheers!
Nick

(If the images are super zoomed in then I'm sure you can right click and 'open in new tab' then zoom out...
The preview looked quite dodgey haha!)

[iiipopes]

Yes, the lacquer on a Besson bell can do strange things. So long as it is just lacquer deterioration, and not the onset of red rot, which yours is not, just keep it clean. I don't know what caused it, but I have the strangest mottling on the bell of my "Bessophone" as well here is the thread on it:

viewtopic.php?f=2&t=61956" target="_blank

BessophoneFront.JPG

[IndyGrabowski]

This is most likely due to formation of CuCl2 (cuprous chloride) by oxidation of exposed copper on the instrument. Careful cleaning and re-lacquering will correct the problem. If you wash the instrument in soapy water, rinse with either distilled, or reverse osmosis water, then dry immediately.

[k001k47]

Your tuba has the blue plague. Please ship it to me immediately for proper disposal, in order to avoid the spread of this deadly tuba disease.
Some fine steel wool or a scotch Brite pad will get that off, along with some of the brass at the surface, and leave a matte - scratched up - finish - which will look rather odd against the spots of lacquer. You can use a polishing cloth, but that takes a lot more elbow grease to buff the same amount of brass off, unless you use a polishing agent like brasso.

That's my cheap bone-headed solution. I'm assuming you don't want to polish and relacquer the horn.

Although. . . Some of the brass appears to be reacting under the lacquer. Curious. . .

[Donn]

As the better part of a month passed before we really got on this at all, have you explored any solutions? I personally don't think there's much to be done for it, short of a full strip and re-lacquer. The lacquer is failing all over, the corrosion is getting in underneath it, and just about anything you do may make it worse.

Are you in the channel islands or somewhere like that with a lot of salt in the air?

[NickIngrþoe]

No I'm located inland, so salt can't be the problem...

As of yet I haven't done anything to it because I have no idea what to do and don't trust myself

It's true that whatever's happening isn't as simple as polishing it off (or maybe it is...), but as Donn and k00 said the corrosion is going underneath the lacquer... It's especially worrying because when I cleaned it the amount of blue went mental and spread everywhere!

As far as doing something is concerned I'm planning on getting some general professional maintenance done anyway, as the valves are noisy and a bit clunky, however I can't be doing that until xmas at the earliest, as I need the thing! Maybe the only solution is to strip it to raw brass - but I wouldn't really feel confident doing that myself...

Whatever the case I can't seem to find any other examples of this top level corrosion, so it remains a mystery.

One thing I have noticed (or rather, haven't noticed), is that the blue hasn't spread anymore since I washed it, so it's got to be something to do with moisture. (Forgive me if that was blindingly obvious haha!).

[Donn]

My sort of poorly informed theory is that lacquer chemistry occasionally has something to do with corrosion. You can find pictures of tubas with similar lacquer failure where the corrosion is red or pink, and I think certain brands are particularly prone to it - maybe due to their lacquer formula. If that's what is happening here, albeit with a difference in color, then it should be no surprise that it's advanced by moisture - whatever it is, I think it would have to be chemically "polar" and hence likely water soluble, to interact with the metal.

That effect may also depend on some unusual environmental condition, though. Wood stove, eating too much cabbage, etc.