5th Valve Lubrication

[Dan Schultz]

I had something come up today and I found interesting.... something I've never really thought about....

Today, a customer brought in a horn that has four pistons and one rotor. The rotor was quite sluggish... like rotors get when the heavy bearing oil eventually migrates into the rotor and things start to slow down. It's pretty much expected that the valves on a rotary horn have to be cleaned every once in a while. But.... since piston oils and rotor oils are usually not the same formulation, what lubricants do you guys use on your pistons... full-knowing that the oil is going directly to the 5th rotor also.

I don't flood my rotors but isn't this exactly what will happen by default to a rotor that is after pistons?

[iiipopes]

honest truth?

Whatever I have: various stuff left over from before I miniaturized the store (Al Cass, Blue Juice, Holton Electric, Spacefiller, cheapo-generic, lamp oil, stuff-begged-off-a-trumpet-player, etc.)

It all works...fine. I simply try to keep my horns reasonably clean, and I avoid damage to the pistons and casings. With these factors in play, my piston tubas aren't picky...ANYthing works FINE.

EVERY ONCE IN A WHILE, (yes) my "5th rotor" will begin to hang...The problem is ALWAYS a "dry" back bearing.

bloke "no quality, just quantity"

13! Same things happen on my 186. Unscrew the back cap and fill the dimple with sewing machine oil and put it back on. I also drip a little sewing machine oil on the top side rotor bearing. All per Roger Lewis. I got a 4 oz bottle of Singer brand oil at Wallyworld for less than $2.

For pistons I do prefer Roche-Thomas, for all the reasons stated above: cheap, does the job, doesn't dilute, stays on the valves, doesn't interfere with rotors, (Occasionally I squirt some down the lead pipe for a "rotor wash") and if I need something heavier to compensate for wear, I drip a couple of drops of pharmacy grade mineral oil into a one-ounce bottle.