Brass instruments need to be cleaned internally on a regular basis. The following is a description of that process. Please note that rotor instruments such as French Horns, Rotor Tubas, and Rotor Trombones should not be cleaned at home, they have special requirements and should only be cleaned by a qualified repair shop.
To clean your instrument you must take it apart completely. You will also need some cleaning brushes (available at music stores), valve oil, slide grease, and some liquid dish soap. You will also need a place to clean the instrument. Unless you have a large sink the bath tub is probably the best place.
1. Carefully remove all slides, valves and valve bottom caps.(Fig. 1&2) Extreme care should be taken with trombone slides as they are very delicate, especially when they are apart! If any of the slides are stuck take your instrument to a repair shop to have them removed. They can be damaged if not removed properly.
2. Place all the parts, except for the valves, in warm, not hot, water containing some liquid dish soap. Let the instrument parts soak in the water for about 10 minutes.
3. While the instrument soaks, take the valves and run warm water over them and brush out all openings in the valves with the valve brush. Shake off any extra water and set valves aside to dry.
4.Next brush out all tubes with the “snake” and the valve casings with the valve brush. Be sure to clean any debris from inside the valve bottom caps.
5. Use clean water and rinse out the instrument. Wipe off any excess moisture and set the instrument aside to dry thoroughly. It is important that the inside of your instrument is completely dry before you proceed.
6. Apply a small amount of slide grease to each slide and reassemble. Be sure not to put slide grease on the main trombone slide. Use slide cream or slide oil on this slide.
7. Install the valve bottom caps. Put a drop of valve oil on each valve and install them in their proper location. Valves are numbered and must be in the correct location to operate properly.
8. You are finished. Enjoy playing your newly cleaned instrument !