Studio of Andrew B. Spang
Contact
Andy
Reference
Articles
Cleaning Trombone
Hand Slides
Rotary valves should be oiled once or
twice every month. Unlike typical piston valves, proper oiling of rotary valves
requires two or three separate kinds of oil: a lightweight "rotor" oil (such as
Hetman Rotor lubricant or MusiChem's Rotor Oil), a midweight "spindle or
bearing" oil (such as Hetman Bearing/Lever lubricant or Paxman 'Spindle/Bearing'
oil), and a heavyweight oil (such as Hetman Ball-Joint lubricant or
'Lever/Linkage' oil by Paxman). Why three oils? A piston valve has basically
only one type of contact: the valve core and the inner valve sleeve. With a
rotary valve, you have three different areas of contact, all deserving special
attention. The first is similar to the piston valve: the valve core and the
inner sleeve (light oil). The second is the valve stem and valve casing (medium
oil). The third area is all the joints along the mechanical linkage found on
rotary valves not using string linkage (the heavy oil).
Here is the proper method for oiling rotary valves. First, push in all valve
slides with the valves depressed. Next, remove each valve's backplate one by
one. Place a drop or two of the medium-weight oil (again, Hetman's Bearing/Lever
lubricant) on the raised circle now visible after removing the backplate. Now
pull out that valve's tuning slide (without depressing the valve). The resultant
suction will pull the oil up the spindle. Replace backplate, and repeat for each
valve.
Then, depress all valves and push the slides back in. Now, place a drop of the
medium oil on the spindle on the front of the valve, just above the bumpers.
Then pull its slide, using the vacuum to pull the oil up the other end of the
spindle. Repeat for each valve.
Now, remove each valve slide and squirt a fair bit of lightweight oil
(Hetman's Rotor lubricant) into the slide. Replace the valve slide, flipping the
valve rapidly to distribute the oil evenly over the valve core. Repeat for each
valve. If you have brand new valves, or especially "tight" rotors, you might
want to use an especially lightweight oil during this step, such as Hetman's
"Light Rotor" lubricant. Experience will show you the best oil to use.
Finally, oil all moving parts of the linkage with the heavyweight oil.
Especially important areas include the screws (or ball-and-sockets) above the
spindles and the hinges (or, again, ball-and-sockets) below the springs. If you
have string linkage (like on most french horns) you may skip this step.
Plan on the whole process listed above to take 15 minutes to half-an-hour.
It is imperative that you oil your valves frequently and properly to maintain
their maximum efficiency. Be sure to oil them whenever the slightest drag or
slowing occurs or if they become especially noisy. This technique should be used
on all rotary valves, including the attachments found on trombones, fifth valves
on piston tubas, and all usual rotary valves found on french horns and tubas.