How a Tuba is Made
Bringing Out the Shine
Repeated polishing using many different techniques
There are a variety of ways to polish metal into a beautiful shine. Automated approaches are making progress, with the inner and outer surfaces of the bell polished by machine, robotic arms used to file the contours, and automatic polishers used to make large swoops around a tube fixed in place. Buffing is also an important process that has long been performed by very experienced technicians.
Are large instruments as challenging as they look?
Buffing is a process that is also used to polish many other brass instruments such as the trumpet and horn. Especially advanced skill is needed, however, to polish a large tuba and its parts. Since the diameter and hardness of the rotating part, as well as its openings, can vary, several machines are used depending on what is being polished and how much it is being polished.
Buffing the tuba with walnut shells?
Let's have a look at one more step in the finishing process-polishing the valves. A device called a barrel is filled with fine, brown powder from ground walnut shells. As the barrel slowly rolls, the powder polishes the surface of metal parts rolling around inside. Walnuts are well suited to this because of their oil content. In some cases, plastic powder may also be used.