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.

A large polishing machine using an array akin to a large set of mops

Before polishing, heat treatment is used on the inside of the instrument. Oxidation produces the bronze color.

A bell that has been polished once (two more rounds await)
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.

Using different machines to polish different pieces of the tuba

Polishing the huge bell of the sousaphone
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.

Placing an instrument into the barrel

The brown powder inside is the polishing agent

When closed, the barrel is a huge hexagon
Musical Instrument Guide:Tuba Contents
Origins
Structure
How to Play
How the Instrument is Made
Choosing an Instrument
Trivia
- A Massive Tuba from 100 Years Ago
- Depending on the Country, a Baritone is Not a Baritone
- The Cinbasso-Popular in Italian Opera
- All Brass Instruments Have Marching Band Models
- Famous Musical Pieces for the Tuba (Bass)
- The Compensating System for the Euphonium
- There are Various Mutes for the Tuba
- Ease of Playing Pedal Tones
- Why Are Tubas So Expensive?
- Do Jazz Musicians Play the Tuba?
- Brass Band Songs Featuring the Tuba
- An Instrument in the Key of B♭, Yet the Music is Written in C