I have recently bought a tuba with a rotary valve system, and I was wondering, how do I oil it? I wasn't clever enough to ask when I bought it, and noone I know knows either.
Thanks

There are several lubrications required.

1.  The mechanism (especially if a mechanical link) should be oiled with a thick oil.  Some people use car engine oil but it need not be quite that thick!  Anything much thinner and the links will rattle and sometimes be sticky.  Take the links apart to oil a ball and socket as well as a pin joint.  Most new instruments do not have the links adequately lubricated - if at all.

2.  The bottom of the valve (some people call this the capston) needs to run smoothly against the valve casing.  This requires some relatively thin oil.  If you unscrew the cap you can gain access to the top bearing which also needs a single drop of thin oil.

In general, you should not squirt or drop oil down the slides.  This has a tendency to was any slide grease into the valve which will make the valve stick - for which the only solution is to take the valve apart and putting it back together takes some skill (ie a technician).  The condensation in the valve is normally sufficient to keep the valve moving and sealing.

windshieldbug wrote on 01/24/08 at 18:22:04:


Thus put the oil into the removed slide, not the open valve tubing, and replacing the slide back in fully before turning the horn should avoid said problem.

With due respect, that exact circumstance could also happen with oil put on the bearining surfaces or in the mouthpipe.  Oil, going down to one micron, could end up anywhere.  When I'm done playing, I push ALL the slides fully in, partially for that reason.

I suspect we've all put oil down the tube when the valve is still sticky after oiling the bearings and links.  However, for the reasons posted above this approach is risky but worth a try when the alternative is abandoning the rehearsal or taking the valve apart.  Once you've taken the valve apart and cleaned it, if the oiled rotor does not freely and smoothly rotate then it needs specialist attention because the tolerances are probably too tight.  Any-one who has successfully reassembled a rotary valve knows that taking it apart is the easy bit, aligning it (and the cap) and ensuring that it neither too far in nor too far our is the tricky bit.

I sometime stand my tubas on their bell vertical, pull out the main tuning slide and VERY CAREFULLY drop oil down the centre (so it does not hit the side walls) while moving the valves with my other hand.  I find this the most effective way of oiling the inside of the rotors and in 3 years I have never had trouble with slide grease getting into the rotors.

I like the system on my Mel Culbertson Neptune which has reversed slides (the slide goes over, rather than inside the fixed tubing) which means no risk of slide grease getting washed into the valves.  I wonder why other tubas to not have this system?

I've put oil in the valve slides of Bb/F trombones many, many times and never had problems.