Band instruments, especially those used in schools, tend to show signs of wear and tear in as little as six months. Taking an instrument to a professional for maintenance can be costly. With the right materials, the work can be done at home for a fraction of the price.
Disassemble the brass or woodwind instrument, including all slides, valves, keys and other moving parts; then place them on a towel to prevent damage. A screwdriver may be needed to remove keys from woodwind instruments. Place any parts that should not get wet (pads, corks, felt padding) off to the side.
Fill the bathtub with hot water and pour in 1/4 cup of liquid dish soap. The dish soap will aid in removing the lacquer as well as clean out the inside of the horn. Place the instrument gently into the water and let it soak for three to four hours.
Remove the instrument from the water and use a paint stripper, following its directions, to remove any excess lacquer. Any paint stripper from your local hardware store will work. Most lacquer will flake off into the bathtub while soaking, but there is usually a small amount that will need to be stripped away by hand. Use a soft wire brush to remove stuck-on lacquer.
Dry the instrument with a lint-free cloth or allow it to air dry.
Spray or brush the lacquer, in a thin layer, onto all outside parts of the instrument. You should be able to find a wide variety of brass lacquers to choose from at the hardware store. Avoid contact with parts of slides, valves and keys that will come in contact with the inside of the instrument.
Place the instrument on a towel and allow it to dry completely before reassembly.
Avoid using the instrument for three to five hours following relacquering, because the change in temperature within the instrument will cause the new lacquer to chip.
Use rubber gloves (dish gloves work well) to prevent skin irritation when removing and applying lacquer.