Published on Sunday, 25 April 2010 15:58
Written by Bruce Gale
Trombones and Tubas
Although brass instruments are generally more robust than woodwinds, students should be made familiar with a few basic principles regarding proper maintenance. Most experienced brass instructors can relate horror stories of serious damage done to brass instruments by well-meaning but uninformed parents and students. Plain neglect can also be depressingly common.
Sugar causes the valves to stick.
Candy, soft drinks and other sugar-based foods should never be consumed either before or during playing. This is because sugar and other food particles tend to lodge inside the instrument and become a breeding place for bacteria. This is particularly so in the tropics. Sugar also causes the valves to stick. Rinsing the mouth thoroughly with water before playing can go a long way towards helping to keep the instrument clean and in good working order. Some schools go so far as to issue plain bottled water to players before a performance.
New instruments should not be used immediately. Instead, they should be flushed with warm water to remove any dust or fine metal particles that may have accumulated in the instrument during manufacture, packing and shipping. For the same reason, the valves of new instruments may also require frequent cleaning and oiling during the first few weeks.
Acidic perspiration contains hydrochloric acid.
Apart from the usual knocks and dents caused by careless handling, the main enemies of brass instruments over the long term are saliva and hand perspiration. Alkaline saliva is responsible for the deposits of calcium chloride that occur in mouthpieces, leadpipes and slide tubing. Such deposits cannot be washed off. Acidic saliva attacks soft solder joints and piston valves. Acidic perspiration, on the other hand, contains hydrochloric acid, which attacks the zinc in the brass. Perspiration with alkaline properties discolors plated and lacquer finishes. All this, and I have not even mentioned the organic materials that collect inside the tubing!
All instruments should therefore be washed regularly in warm (not hot) water. For this purpose, you will need a bucket or perhaps a large sink or bathtub, depending on the size of the instrument. If the instrument is particularly dirty, soap may also be used. Manufacturers such as Yamaha produce special brass soaps for this purpose. A mild dishwashing detergent works just as well, however. Avoid toilet bowl cleaners, baking soda, oil soap and drain cleaners. Remember also that the instrument must be rinsed thoroughly afterwards to prevent dried soap particles gumming up the valves. Boiling water should be avoided. It forces the metal to expand and can cause serious damage at stress points.
Mouthpieces can be boiled if necessary.
Most of the dirt tends to accumulate in the leadpipe and the mouthpiece. These areas should therefore receive particular attention. Small flexible brushes can be purchased from most suppliers for this purpose. Unlike other parts of a brass instrument, mouthpieces can also be boiled if necessary. If a mouthpiece shank has been knocked out of shape, it can be fixed with a simple truing tool. Some authorities also suggest putting a few drops of valve oil into the leadpipe to help prevent the build up of grime.
Because brass and nickel silver alloys can be toxic, it is important to ensure that your students do not use old mouthpieces that have lost their plating on either the cup or the rim. Bare brass mouthpieces offer no acoustical benefits and can be a health hazard, particularly if they become corroded.
The valves should be kept well oiled, but not excessively so. Oil is no substitute for clean valves. Too much oil simply helps the sludge accumulate more quickly. Amateurs sometimes use saliva as a substitute. Although effective in the short term, saliva contains acids that are injurious to the valves. If your students do not have any valve oil, tell them to use water instead (dry valves often respond slowly, if at all) and make sure the valves are cleaned frequently. Do not attempt to use substitutes such as kerosene or sewing machine oil. This will only make matters worse.
Do not clean valves with rough sponges.
Considerable care needs to be exercised when cleaning the valves. Once removed from the casings, they should be wiped gently but thoroughly with a clean, soft cloth. Do not immerse the valves in water. This can damage the felts. Under no circumstances should valves or slides be cleaned with rough sponges of the type used on household pots and pans. Avoid using sandpaper, steel wool or scouring pads. The above materials will damage the valves by either scratching them or removing some of the nickel plating.
The interior of the casings should be cleaned using a soft lint-free cloth. When using a swab it is important that the metal end is well covered to prevent accidental scratches. After cleaning, the valves should be placed back into their casings following the numbers engraved on them.
Valves should never be dropped. Even the slightest bump can throw a valve out of alignment with its casing, causing it to respond sluggishly, if at all.
The tuning slides should also be removed regularly and lubricated lightly with tuning slide grease. Petroleum jelly is not an entirely satisfactory substitute. It is a corrosive that eventually results in the valves becoming stuck, particularly in the case of poorly maintained instruments. If the slides become jammed and cannot be removed with a moderate degree of pressure, try soaking the instrument in water for several hours. If this does not work, call in a competent repairperson. Serious damage can result from the use of brute force in an attempt to remove a stuck mouthpiece or tuning slide.
Regular "popping" can produce leaks.
When removing tuning slides, the affected valve should be depressed. If this is not done, a popping sound results as the air pressure equalizes. Regular popping can produce leaks in the valve or the slide.
Trombones and Tubas
The trombone slide is particularly vulnerable to damage because of its delicate construction. Students should therefore be instructed to handle the instrument with great care. For example, they should never assume that the slide is locked. Instead, insist that players get into the habit of always picking up the trombone by the two side braces. Similarly, no trombone should ever be left balanced on a chair. When drawing up seating plans, ensure that there is plenty of playing room for the trombones so that the outer slide does not knock against other objects. Trombone slides are lubricated either with slide cream and water, or with oil, never both.
Avoid placing a tuba or sousaphone on the floor with its bell down. The weight resting on the bell can cause a dent or bend. Instead, place the instrument on its side or in the case provided.