Trumpet Repair

The trumpet is a fairly simple mechanism and the problems that sometimes  afflict it are pretty universal.  They include:

• Stuck mouthpieces
• Sluggish or sticking valves
• Stuck slides
• Broken solder joints
• Dents

Stuck mouthpieces are the easiest to fix so let's talk about those first.  Mouthpieces are easy to get stuck because the mouthpiece shank is conical—it goes from narrow to wider.  When the mouthpiece is placed in the trumpet it should slide in until if fits  snugly; at that point it won't leak air and it shouldn't fall out.  But if it gets bumped in further, it often gets wedged and won't come out.  And with the mouthpiece stuck in the receiver the trumpet won't fit in its case.  Pliers and vice grips are exactly the wrong tools to remove it, as trumpet brass is soft and bends easily.  The technician (and sometimes the band director) has a special tool for pulling stuck mouthpieces; with the right tool it takes only a couple of minutes—and nothing and nobody gets hurt.

Sluggish valves are a real nuisance because they don't keep up with the player; playing is hard enough without fighting your instrument.  Sluggish valves have two common causes: there is dirt or something foreign in them, or the piston or its casing is bent out of shape.  You can usually tell which it is by how consistent the problem is—if the valve sticks every time it's played, something is bent; if the valve sticks intermittently, it's dirt or some impurity in the valve.

Cleaning the valves is something every trumpet player should know how to do.  In a large sink or bathtub of warm water and mild dish soap, disassemble the trumpet and gently scrub the insides with a valve and slide brush.  Rinse the parts thoroughly, dry them off, apply a little slide grease to the slides and a little valve oil to the pistons, and reassemble.  (Be sure to get the pistons in the right casings.  They're numbered; the #1 piston goes in the casing closest to you.  And turn each piston until you hear the valve guide click into place.) 

If thorough cleaning doesn't fix a sticking valve, either the piston or the casing is bent and a technician will need to straighten it.  The tolerance between the piston and its casing is very small so air doesn't leak as the trumpeter plays.  A small dent in the casing or a slide bent slightly into the casing will drag the piston as it moves through.  The technician has special tools to remove dents while maintaining the close tolerances necessary for playing well.

Stuck slides are sometimes the result of an accident or bump, but usually they're caused by the chemical bonding of impurities left on them.  Sometimes they'll come apart with a little pressure—but not pressure applied with a hammer or pliers.  The technician will likely try a soft belt and gentle tugs first.  If that doesn't work, he'll probably apply heat.  And if that doesn't do it, he'll have to disassemble the trumpet at its solder joints, attach something sturdy to the slide tubes, and apply enough heat and pressure to separate them; then he'll solder the trumpet back together.  The outcome is much prettier than the operation.

Broken solder joints happen when a trumpet is dropped or twisted.  The technician straightens whatever is bent, thoroughly cleans  both sides of the joint, and fits the parts back into place.  Then with a gas torch he heats the joint to a temperature high enough to melt the solder but not high enough to burn the finish, carefully flowing the solder across the whole joint.  When the solder cools he cleans around it—and it's good as new.  (Don't try this at home.)

Dents are where the true artistry of a good technician shines through.  Using special mandrels and other burnishing tools the technician rubs and pounds out the dent until the metal is smooth again.  Sometimes when the trumpet's lacquer or plated finish wasn't damaged in the accident, you can hardly see where the dent was.

There's little damage to a trumpet that can't be fixed, and when it is, the trumpet should play like it did when it was new.