By Carolyn Albert, McLean VA
I learned effective brass cleaning procedure through a process of elimination. After buying every available brass polish at the hardware store and experimenting with different techniques, I have landed on the following as my brass cleaning MO:
It is helpful to determine what type of brass finish you are working with and how much energy you want to put into the cleaning process. For example, are you doing a quick fix to make a customer happy, or are you putting in a more substantial effort with intentions of reselling a piano? If you are in a client's home, you may want to eliminate as many odors as possible and take extra time to prepare your work space. If you are in a shop, you may have the ability to be more relaxed in your approach, but achieve a more thorough result. I typically work in a shop on pianos built by major manufacturers within the last 50 years. This article is generalized and can be tweaked based on what environment you are working in.
Identify the type of brass
Solid brass can be identified with a magnet. If the brass is solid, the magnet won't stick. Some people suggest scratching a hidden part of the brass, but I avoid that technique on the general principle of "do no harm," and plating thickness may not be consistent across pianos.
Note: My preference is a heavy-duty magnet made for holding license plates on automobiles (which also serves double-duty if I drop screws made of other metals and want a quick clean up.)
Solid brass is the easiest to work with and typically turns out well with minimum effort. In addition to polishing, solid brass also tolerates light sanding and machine buffing to remove significant rust.
Brass plating can also be identified using the magnet, which will be attracted to the underlying metal and will stick.
Brass over another metal gives you less brass to work with if it is rusted or pitted, but otherwise, responds well to standard polishing techniques.
Lacquered brass can be identified by a noticeable film that has signs of wear through it on the area where the foot contacts the pedal, or by pitting formed when there is a hole in the lacquer and rust has developed. Some brands are known for using lacquered brass on all of their pedals, such as Kawai. Lacquered brass is not covered in this article, as it does not lend itself to typical polishing methods. (Frankly, I usually skip attempted polishing techniques on lacquered brass and buy new pedals.)
Let’s start with the simplest case and work our way up. We are assuming for this article that the piano is being cleaned in a customer’s home or a technician’s facility and does not cover restoration.
Prep the work area
Remove brass from the piano, if possible. If you are working a grand piano with excessive wear, it is often easier to remove the lyre and pedal assembly and handle the pedals and pedal rods separately.
If you have to leave the brass on the piano, tape off any adjoining areas, including the felt surrounding pedals.
Put cardboard or other material underneath the brass to protect the floors or table.
Remove heavy tarnish, pitting, or rust
This can be done with untreated 0000 fine steel wool and elbow grease. Heavy rust or pitting may need additional sanding by hand or with a bench grinder.
Remember that brass is a soft metal and assemble a number of different grades of sandpaper. Typically, I start with a coarser grit (800) for rust and a light grit (1500) for minor scratches. Either of these grits will leave noticeable marks on the brass that can be removed by sanding with extra fine grades of 2000 or 4000 grit.
Heavier rust can be removed more quickly using a bench grinder if available. Follow the manufacturer’s recommendation for selection of the proper grade of pads keeping in mind that brass is a soft metal. Typically, I use the finest pads and buffing compounds available to start with. If you are new to bench grinders, practice on an unneeded piece of brass before you work on a client's piano. There is a learning curve to bench grinders, and brass can be destroyed easily if you don't know what you're doing.
Remove medium amounts tarnish or discoloration
Heavy tarnish, discoloration, and minor rust can be removed with Noxon. Coat liberally and let sit for 20-30 minutes. Do not let it dry! Then, use cotton pads or cloth to polish. My preference is to make pads that can be thrown away. Exfoliating cotton pads are great to add a little more cleaning power. You may need to do this twice.
Small pieces of brass (eg cruddy hinge pins), can be soaked in Noxon in a small glass or plastic bowl.
If the brass on the piano is a matte or flat finish (frequently found on Steinways), stop here.
Mirror/High Shine Finish
Hope’s Brass Polish provides a nice, shiny finish, but does not remove buildup very effectively. It also does not require any “soaking” time and can be done very quickly. I use this after a soak or two of Noxon to achieve the mirror shine after the bulk of the buildup has been removed.