Duncan Harris is a luthier and bow maker based in Ann Arbor, Michigan. We welcome him with his first guest article about keeping your strings clean for a better sound. He particularly enjoys doing high quality rehairs and setup work. See Duncan’s website at dwhbows.com.
Any string player is familiar with the sticky coating of rosin which accumulates on both instrument and bow. The rosin may seem innocuous and is easy to ignore, but it is worth the time to clean it off every time you put your instrument away. Obviously this will keep your equipment looking its best, but what is less obvious is that even just cleaning your strings can make your instrument sound noticeably better!
How can rosin change my instrument’s sound?
Most importantly, rosin attracts contaminants, and dirty rosin can’t engage in the crisp stick-slip motion necessary at the interface between the bow hair and the string. The string actually bonds to the bow hair and then breaks free hundreds of times per second. The abrupt snapping free produced by fresh clean rosin is the most efficient way to excite all of the overtones at once. Learn more about this relationship here.
Additionally, even clean rosin changes the sound slightly as it accumulates simply due to its mass added to the surface of the string. The whole instrument functions to immensely amplify the motions of the strings, which rapidly twist and kink hundreds of times per second. This means that the closer something is to the surface of the strings, the more sensitively it affects the sound. That is why string manufacturers carefully tune the density of string materials, even at significant expense.
When adjusting instruments, my golden rule is “everything matters”. I have personally heard changes this small noticeably affect the sound:
0.5g on the surface of the instrument
0.05g on the bridge
0.005g change in a single string overall weight
0.0005g concentrated on the surface of the string
Notice how tinier and tinier changes become audible as one approaches that crucial string-bow interface!
How do I clean my strings?
A fresh coat of rosin powder from today’s playing is easy to remove. Gently wipe your strings lengthwise with a soft cloth that is clean and dry. You can keep one in your case and launder it occasionally to remove oils from your hands. Wound strings are easily damaged by scrubbing or twisting, so go lightly. Through the cloth, the strings should feel evenly smooth from end to end when they are clean. If the strings remain sticky or dirty near the bridge despite a few gentle wipes, stop and proceed to the instructions for caked on rosin.
Dealing with extensive rosin buildup
If a dry cloth won’t cut it, you will need to use a solvent to dissolve the rosin. Caked on rosin is similar in many ways to varnish, so anything which can dissolve rosin is also very hazardous to your instrument’s finish. A drip or smear can do serious damage in less than a second. Most luthiers have high proof alcohol for working with varnish and will use that for string cleaning as well. A player at home can use just about anything clean with alcohol in it. Rubbing alcohol or high proof grain alcohol would be good options. I do not recommend aftershave, hand sanitizer, or anything with sugar in it.
Away from the instrument, apply your solvent to a 5 cm square of paper towel. Be sure that the towel will not drip even when squeezed before you approach the instrument. Work one string at a time, gently pinching the string inside the towel between your thumb and finger. Move slowly at first to give the rosin time to dissolve. Once the string looks clean, you can shift to a clean area of towel and lightly travel the full length of the string to ensure that it feels even from end to end. Sometimes this examination will reveal a defect in the winding of an old string which is nearing the end of its career.
This cello came in for a setup last week and needed more than a dry wipe to clean its strings. Now it is back with its owner, cleaned up, and sounding better than ever!