Cleaning valve casings

[kingrob76]

I have, in my possession, a 25-year old horn that has had a hard life and the valve casings need a really good cleaning. Ultrasonic or chem cleaning are not options in the near term.

What are some viable ways to actually clean the insides of piston casings? My first thought was a soft toothbrush with soap and water, but, it being raw brass I'm worried about actually damaging the surface.

[BRS]

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[bloke]

Yes sir.

When I see pistons and casings that look like the owner has been really conscientious about cleaning them - yet there's intermittent sticking, what I find is that they have failed to clean out those difficult to reach connecting tubes and knuckles that feed into the casings and pass through to the next casings. Often those are filled full of crud from decades, because all they have done is run a brush over the easy to reach surfaces.

[bloke]

I'm generally pretty "proud" of my valves.

I had some really close-tolerance and super-smooth/super-reliable pistons on a (very nice) tuba (one that I've since sold).

One of the pistons was giving me a problem.

I eventually discovered that there was a hair (surely: one of mine) laying on the piston wall.

[kingrob76]

So after some "vigorous" cleaning, these casings have faint outlines of the pistons - you can see where the ports were "at rest" and where the bottom of the piston was at rest. This horn had a hard life. The rest of casing looks pretty good.

It's always something.

[bloke]

So after some "vigorous" cleaning, these casings have faint outlines of the pistons - you can see where the ports were "at rest" and where the bottom of the piston was at rest. This horn had a hard life. The rest of casing looks pretty good.

It's always something.

If it's only brass oxide - and the brass oxide is lapped smooth from the valve going past it all the time, I don't see that as a problem. (Of course, I haven't seen your instrument, so I'm not 100% certain what you are describing.)