Red rot... Or not?

[NLeuph]

Hi Guys,

I bought a second hand euphonium . I only discovered a few spots now, hoping it is not red rot. Could you take a look at the image to examine? I am really curious to what you guys think.

Thank you!

[davewerden]

No rot. Just normal tarnish from what I see.

[NLeuph]

Thank you for your fast response, and from the maestro himself . I was a bit anxious about the reddish dots. But that is quite a relief if it is just tarnish, because it doesn't come off with polish.

[highpitch]

Red rot usually sets up shop where tubing enters a valve casing.

Seems to come from the acid flux used in soldering not being rinsed away completely during manufacturing, leaching the zinc out of the brass and leaving the reddish copper.

[iMav]

https://www.hornmatters.com/2011/05/what-is-red-rot/

[NLeuph]

Thank you for your responses. I did find that site too, however unfortunately it is quite hard (at least for me) to distinguish tarnish, acid bleeds and true red rot. So I am very grateful for your thoughts on this matter.

[John Morgan]

Here is a picture of red rot on the leadpipe of my Adams E3 (which Adams replaced).









Yours does not look like red rot.

[bbocaner]

surface corrosion. red rot starts on the inside at places where gunk tends to hold moisture, and by the time you see it on the outside it's pretty extensive. Also, it typically only happens on yellow brass and not on red brass or across nickel silver parts like you have in your photos.

It does look like it may have started underneath the lacquer on your instrument, which could suggest that the lacquer failed or the instrument wasn't perfectly clean in that spot when they lacquered it. That's why it's not just polishing off. It's ugly but it's not going to ruin the instrument.

[NLeuph]

Thank you for all of your reactions. I am relieved it is not red rot. I agree with you bbocaner that it is ugly. Luckily it is not really conspicious for the viewer. I just know where it is. The instrument (a Geneva mentor) plays really well and sounds really good to my ears :-). So I am happy it is just cosmetic damage.