valves should be oiled regularly at the end bearings with a good
quality light machine oil such as Singer oil. The job can be done
more neatly with a precision oiler which has a needle applicator
(available from electronics stores).
valve oil should be used inside the valves. Remove the tuning
slides and drop 3 or 4 drops into each valve. Try to get the valve
oil down the slide tubes without it touching the sides as this
will remove some of the slide grease and get it into the valves
necessitating regreasing of the slides and more frequent cleaning
of the valves. Incidentally, I find wool fat (available from the
chemist) to be an excellent and inexpensive tuning slide lubricant.
a period of time old valve oil thickens and, in combination with
scale and corrosion, makes the valves sluggish. Regular use of
fresh oil will thin the old oil temporarily but eventually the
valves must be cleaned.
Valves can be flushed with kerosene and with warm soapy water
to remove some of the old oil but to do a thorough job they must
be taken apart and cleaned.
will need the following tools, etc. to work on
-Screwdrivers to fit rotor stop screws and rotor stop
-An old toothbrush and/or a valve brush
-A rawhide or wooden mallet
-A piece of 25mm dowel 50mm long with a 10mm
hole drilled in one end to a depth of l0mm (optional)
-An apron or towel for your lap (so that parts don't
fall on the floor when working in your lap)
-A work bench covered with an old towel (to absorb
water and keep small parts from rolling away)
-parts from different valves must never be
interchanged. Always check that all parts are clearly
marked as they are disassembled. If the markings
are not clear, re-mark then (e.g. with 1,2 or 3 lines or
dots scratched into a non-contact surface on parts
of the 1st, 2nd and 3rd valves respectively).
remove the old valve strings if you wish to replace them. Make
valve levers don't snap up and hit any of the tubing.
remove the valve caps. Then turn the instrument over and lay it
in your lap
on the apron or towel. The next part of the operation is done
in your lap
because you will be tapping on the rotor ends and your lap provides
padded surface where the impact of the mallet isn't carried through
to damage any
part of the instrument that may otherwise be in contact with the
the first rotor stop screw 1/2 turn and, with the screwdriver
squarely and firmly in the screw slot, tap the end of the screwdriver
until the screw head is again in contact with the rotor spindle
end. It's possible to bend or break off the screw head if the
screwdriver blade isn't exactly centred and square in the screw
head slot. Loosen the
screw another turn and repeat the process until the rotor and
back bearing fall
out into your lap. Alternatively the rotors can be removed by
first removing the rotor stop screw entirely tapping the spindle
end with the thin end of a chopstick or thin dowel. This method
avoids the possibility of damaging the screw but care must be
taken not to damage the threads in the rotor stop screw hole,
or get a piece of the dowel stuck in the hole. When the rotor
and back bearing are free, check that both parts are clearly marked
and place them on the work bench. Disassemble the remaining valves
in the same manner.
rotors, back bearings and rotor caps in hot water with detergent.
Scrub each part with an old toothbrush. Deposits. of corrosion
and scale may be scraped gently with your fingernail but never
use metal, steel wool or abrasives to clean
valve parts. Stubborn corrosion and other deposits must be removed
chemically by Campbell Brasswind Service.
all parts and set then out on the work bench ready for assembly.
the valve casings with hot detergent water and a toothbrush or
valve casing brush. Rinse.
the first rotor and put a drop of machine oil on the rotor spindle
and a few drops of light valve oil on the middle part of the rotor.
Put it immediately into the correct valve case ensuring that no
dirt gets in. Put a drop of machine oil on the back bearing and
slip into place on the rotor. Line up the positioning marks on
the back bearing and the edge of the valve case. Tap the back
bearing into place by placing the piece of dowel on the back bearing
with the 10mm hole over the spindle and firmly tapping the end
of the dowel with a mallet. Then tap around the circumference
of the dowel end until the back bearing is completely seated in
the end of the valve casing. Now slip the rotor stop into place
on the end of the rotor spindle and screw in the rotor stop screw.
Assemble the remaining valves in the same way.
Replace the strings as in the diagram and adjust the key height
by sliding the string around the rotor stop and rotor stop string
screw. Tighten the screw just enough to hold but not cut into
the string. Now check the key action. If the key binds somewhat
it could be that the string is too tight. In that case loosen
the key lever string screw and pull the string back through the
hole a bit while re-tightening the screw.