Cleaning Cello Strings
When you finish playing, wipe off your strings with a soft, clean cloth (some player prefer a chamois for this job). Sweat is corrosive and will eat right through strings over time, shortening their lifespan considerably. Still, cleaning cello strings is of limited effectiveness against sweat and moisture, which get inside the strings, but it helps a little. Grime tends to collect on the underside of the strings so be sure to run your cloth between the strings and fingerboard, too.
Rosin builds up on strings long before they need replacing. Alcohol is the best way to clean the strings—rubbing alcohol or the solvent from the hardware store, it makes no difference. It is fast and easy, but an errant drop of alcohol will eat through your varnish faster than you can blink so you have to be very careful. Prepared, individually packaged alcohol wipes of the type used to clean the skin before drawing blood or giving an injection are a convenient way to clean the strings. If you want to be extra careful, try holding the instrument by the neck, turning it face down while you work so that any drips fall harmlessly to the floor.
Lightly grip each string with the pad and run it quickly back and forth. It might take a bit of effort to get all the rosin off—rosin has a very low melting temperature, and forceful playing can heat it enough to melt it, case-hardening it around the string.
But after a few passes the string will come out shining brightly; even the tarnish will disappear. You can then use the pad on the fingerboard itself, to get rid of accumulated dirt and rosin. And you’ll be amazed at how much there is, too. When the pad is black (yech!), open a new one and keep going. Use a dry piece of new paper towel to polish the fingerboard, and you’re done.
If, with playing, your strings get white fast, or if the top of your instrument under the bridge looks like the shoulders of someone with a seriously horrific case of dandruff, then you’re using too much rosin. It’s a vicious spiral to get into—the more rosin you use, the less well the bow grips, and so you use more and more to less and less effect. Instead, try cleaning the strings or getting a rehair.
Now: oops! Somehow a drop of alcohol got on the fiddle. Don’t touch it! Don’t do anything. An “alcohol bloom” can easily be polished; an abraded spot, upholstered with fuzz from your paper towel, requires serious retouching.