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Hello! So, I am a college student who bought a MackBrass horn a few years back just after covid made its way into the world. Since then, I’ve been noticing that the horn is tarnishing a lot on the bottom side of the bell tubing. It’s turning green. Looking into it, some call it verdigris? Is there anyway to remove a large partition of this from a 4/4 sized tuba? Any tips or suggestions to stop this from happening would be great as well! Thank you!

Is the tarnish on the inside or the outside? If outside, it’s probably under lacquer and not much to do except strip the lacquer then polish it. If inside that’s raw brass. That could be removed with something acidic. Vinegar would probably do the trick. If outside that would represent a manufacturing defect where the lacquer failed somehow or there was moisture trapped underneath somehow. If inside just try to keep the inside of your horn dry. After I’m done playing I use a special swab made by Yamaha to get all the trapped moisture out of all my slides. That’s where most moisture gets trapped. In the bell? Not sure. Do you spin your tuba to try and get moisture out of the bell?

If it's coming out of the rim, it's probably solder acid residue from when they soldered the rim bead with lead solder. People call that acid bleed.

Hi! Thank you! It’s actually on the outside of the horn. The finish has been turning green and it’s right where the under part of the forearm rest.

RyeGuy25 wrote: ↑Fri Nov 10, 2023 8:19 pm Hi! Thank you! It’s actually on the outside of the horn. The finish has been turning green and it’s right where the under part of the forearm rest.

Yeah, a picture would be good, but I used to do this to my horns when I was younger and perspired more - if you're talking about the connection ring between the bottom bow and the bell. This doesn't happen with my tubas anymore, now that I'm older.

Hope this photo helps! There’s not a lot of it, since it’s already gone, but I’m looking to sell the horn and try to understand what this is from/ how to prevent it.

The picture is not particularly well focused - and I'm not criticizing the picture taking, but if I'm seeing what I think I see - which is simply worn off lacquer, brass is going to turn green if it gets perspiring skin against it.

Based on a guess that you don't have access to the ideal types of supplies, I would probably suggest purchasing a product called Brasso, shining up the area is nicely as you with that product - even though the surface is going to be a little scratchy and pimply looking, cleaning it off with a solvent like lacquer thinner - or even gasoline - on a soft rag, going back with a silver polishing cloth and cleaning off the solvent and final traces of the Brasso, going over it once again with a old soft t-shirt gently, and then spray a few careful coats of clear rattle can lacquer on that area. Be sure - before spraying - to carefully run a skinny nail in the trim lines of the connection piece between the bell and bottom bow to get Brasso and other crap out of those trim lines. Practice spraying the clear lacquer on something else first, so you can figure out how to get shiny coats without getting runs. In other words, moving slowly enough to where it goes on like a sheet of plastic, but not too slow that you put so much on there that you get sags. With rattle can lacquer, I would probably suggest two or three coats, since it is not epoxy, and it is an area where you put your arm. There are some tricks that I do additionally that involve fire, but I strongly discourage any of that, so I'm not even going to go into an explanation, as it's obviously dangerous, and has to be done just so.