Twelve
Ways To Avoid The Brass Repair Shop – Part Two
by Robert Baca & John Huth
With
ever decreasing budgets and the band director’s need to become more
efficient, the “I don’t know how it happened” avoidable
repair can add up to more than a bottle of Tylenol. With a little neglect,
or using the wrong method of “band-aid” remedy, small repairs
can eat away at the budget, and cause instruments to be missing from rehearsal.
To provide some sound advice for students, I asked nationally recognized
brass repair expert John Huth to identify the most common problems that
eventually guarantee a student’s horn a trip to the repair shop.
In the last issue of Kjos Band News we provided general tips on
horn care, and tips for piston instruments. In this issue we tackle French
horns, rotary valve tubas, and trombones.
FRENCH HORNS AND ROTARY VALVE TUBAS
Learn How To Re-string Your Valves
The band director or a repair shop can demonstrate
how to properly tie the rotor so it operates freely and lasts a long time.
For string, use a woven nylon or rayon fish line, minimum 50-lb. test.
Monofilament line is not recommended for French horns. Remember too that
the paddle height is adjusted at the rotor bumper arm, not by bending
the paddles.
Lever Arms
It is not unusual to find levers bent to
all sorts of odd angles relative to the stop arm, even on instruments
direct from the factory. Valve action can be greatly improved if the levers
are as close to the stop arm as possible, and in a side angle where the
lever arm is parallel to the stop plate face when the stop arm is directly
between the two string holes (see below).
| Lever A is in the correct position for effective stringing. Lever B is too far from the stop arm, and Lever C is bent to the wrong angle. Both levers B & C will force the string to rub on itself—increasing drag and shortening the life of the string job. |
| Position A shows the lever in rest position, where the lever arm should be angling slightly upward relative to the stop plate. Position B shows the lever in mid-stroke, where the lever is parallel to the stop plate and the stop arm centers between the two string holes. Position C is the end of the rotor stroke. While this exact set is not possible with some French horns, it is at the very least a place from which to begin when stringing a horn. |
Stringing
The choice of string is up to the technician,
though it is recommended that the technician seek a woven rayon or nylon
line of 50-lb. test or greater. Many shops have been using the line sold
by Yamaha with great success, though the string is only a small part of
the job.
The keys to the longevity of French horn stringing lie in insuring that the lever arm angles are proper (the string should never rub on itself), as well as in keeping the string set screws tight enough so the string cannot slip out.
Tie the string as shown, with the string wrapping under itself to lock it under the string set screw heads (see below).
Lubricate Your Rotors At
Least Once A Week
Use a heavy 30-wt. oil on the spindles and
rotor oil on the valve face, oiling through the valve slide tubes once
a week! Most manufacturers sell oiling kits that have the proper oils
and instructions. Rotors can wear out within a year if not properly lubricated.
Spindle Photos
Valve
Slide Photo
TROMBONES
Wipe Your Handslides Once A Week
Whether you use slide oil or slide cream
and water, the build-up of lubrication and debris between the inner and
outer hand slides can seriously affect proper slide action. Use 100% cotton
cheesecloth to wipe off the slide and wrap it on a cleaning rod (purchase
at a music store) to wipe the outer slides
. Follow
these suggestions and you’ll save both money and a trip to the repair
shop!
John Huth has been an instructor in the Band Instrument Repair Program
at nationally recognized Minnesota State College-South East Technical
(Red Wing) for the past thirteen years. He has presented seminars on brasswind
repair and maintenance nationwide and is honored to be a Master Repair
Clinician for the National Association of Professional Band Instrument
Repair Technicians (NAPBIRT).
Copyright © 2001
Neil A. Kjos Music Company. All rights reserved.