Buffing and Polishing Brasswind Musical Instruments
Glossary of Buffing and Polishing Terms:
By: J.L. Bowers, The Bandroom

Safety Precautions- Most people don't have enough knowledge about the art of repairing a musical instrument to even begin to realize how dangerous it really is. Refurbishing a horn is not only: Hot, sweaty, dirty, and uncomfortable work. It is also extremely dangerous and the equipment used is unforgiving. It would be very easy to lose an eye or even a limb when repairing a musical instrument. Refurbishing a horn can take as many as 60-80 hours to complete, depending on the size. Therefore, a repair technician must observe safety precautions at all times.

Spray Sock- This covers the entire head to reduce the amount of compounds that get into your hair, which ultimately sink into the pores of your skin.

Coveralls- A body suit to cover your normal clothes from head to toe.

Safety Goggles- To cover your eyes so that the buffing machine doesn't sling loose compound, or a piece of the horn into your eyes.

Breathing Apparatus- A device that has a built in, replaceable filter. This fits over your head and locks into place. Fresh air is a must when buffing. You certainly don't want to breathe in all of that dust into your lungs! This is used in conjunction with a vaccum operated dust collector.

Gloves- To protect your hands from buffing wheel burns, and to allow you to hold the horn more comfortably. Buffing a horn creates a lot of friction, and the heat can be overbearing. Some technicians use a different pair of gloves for each compound being used.

Lighting- When working with a buffing machine, or other heavy equipment, always make sure you have an adequate source of good lighting. It is easy to overlook an area that needs more attention, and a brief walk outside under the natural sunlight will also let you know how the horn looks.

 
Roughing- Unlike building a new musical instrument from scratch, an overhauled instrument usually requires extensive preperation. Usually, the horn must be stripped, disassembled, and dents are removed using various rods and a series of graduated dent removing steel balls. Often, if a musical instrument is in very poor condition, an experienced technician can: sand out deep scratches, patch holes, braze or silver solder broken braces, and even custom fashion parts that are obsolete. Once all of this work is complete, a very rough grit of buffing compound is used on these sanded/ground areas to get the overall surface condition of the instrument even. This step is called roughing out the horn. Some repair technicians use the term polishing as well.

Buffing- This is the final series of steps to obtaining a good finish on a brass musical instrument. There are hundreds of compounds that can be used in this process. I have found that these are the best used to get a shiny finish with the least amount of hard labor.
Use these compounds, in order;
Butler(Aluminum Oxide)Compound- Raw Polishing
Tripoli(Amorphous Silica)Compound- Raw Cutting
White(Refined Amorphous Silica)Compound-
Iron-Free Chrome Cutting.
Red/Black(Ferrous Oxide)Rouge- Raw Coloring
Yellow/White(Aluminum Oxide)Rouge- Nickel/Chrome Coloring
Green(Chrome Oxide)Rouge- Silver Cutting

Buffing Wheels-

Muslin/Cotton- Circular discs of material stacked in various thicknesses and sewn together. The tighter they are sewn, the stiffer they are. The looser sewn wheels are used in order that they conform more to the shape of the instrument. The thicker wheels are used for cutting/polishing large areas like a bell. The thinner wheels are good for tight areas and small parts such as woodwind keys and finger buttons.

Chamois- Circular discs of leather stacked in various thicknesses and sewn together. A chamois wheel is used mostly for cleaning up an instrument after general playing condition work is complete. Generally, these are mostly used with various rouges. It is also a good idea to either wipe down, or degrease the horn between steps.