the best type of pistons for valve oil...(??)

[bloke]

To me, the best pistons for valve oil are those that are precision made, perfectly cylindrical, and are precision fit in similarly well-made valve casings.

Such pistons also seem to work remarkably better with valve oil when they are not coated with hard scale, and the same goes for their casings.

Not surprisingly, such pistons seem to work best when they are not anywhere near gooey over-applied slide grease - which otherwise could migrate into and mix with valve oil - at least, in my experience. I've also found it handy to have the slides fit just about as well as the pistons, and to be remarkably well aligned - so that I can use the same type of oil on the slides that I use on the pistons. This way, I don't have to worry very much at all about two types of lubricants mixing with each other in an instrument, because there's only one type being used for everything.

I'm not sure, but I also believe that scraping stray particles out of bottom valve caps and occasionally reaching into the difficult to reach porting between valve casings with my fingers (or extremely carefully, with a flexible brush) and scraping the same kind of crap out of those places it's probably a good idea, because those particles don't seem to function particularly well as lubricants, and nor do strands of hair, whether human or pet.

Most of the same things seem to be true for rotary valves, in my experience...

... so what do some of you folks think?
Has anyone found that poorly-made valves with scale and stray particles on them work better with valve oil than the type of valves described above?

[Rick Denney]

Ha, ha.

All surfaces that move will wear faster if not lubricated. But I doubt that the lubricity is what makes them smooth. Good valves are smooth even when they are dry, at least until wear products build up.

I just chem-cleaned my Hirsbrunner, including soaking the rotors for a few minutes in 35% vinegar (acetic acid). In about three minutes the hard scale was gone. It also cleaned the scale out of the valve slides, though I didn't soak those without paying very close attention. It didn't completely remove the brown oxide that shows the surface has been appropriately burnished, and I didn't want to remove that in any case. The whole tuba got a bath in 10% vinegar for a couple of hours. That's about twice the concentration as salad vinegar, and it was enough to clean out scale but not so much that it really took off tarnish, let alone silver plate. I have also used the same cleaner that I use for cleaning brass watch and clock-movement parts, but that stuff will abrade the surface in an ultrasonic bath if left for more than about three minutes. I used that for the rotors on the Giardinelli/B&S 101, but those valves were in serious need of surgical cleaning. The vinegar is more forgiving.

Funny, but those old B&S rotors are badly worn and still they work really just fine after being properly cleaned.

Rick "lubricated" Denney

[bloke]

I cleaned the big Miraphone in a cleaning acid very shortly after I purchased it, and it needed it. I'm doubtful that I will ever do it again. I slosh a bunch of my secret formula oil around inside of it every time I pick it up to play it.

There's actually a little bit of scale inside the body bows of the instrument that I've seen, so just might pull the tuning slide, and rotate the tuba every few minutes - soaking each of the body bows individually, and then rinse.