Lap pistons and slides of brass musical instruments.
What does a Preassembler and Inspector do?
Laps pistons and slides of brass musical instruments to ensure that joints slide freely: Screws piston onto shaft attached to handle, and brushes pumice compound onto piston. Inserts piston into matched valve, and laps it until it moves freely. Moves sliding joints to detect binding action. Applies abrasive compounds to slides, and files and laps them until they move freely. Inspects soldered joints for excess solder and rejects unacceptable joints.