(Originally posted here: http://www.allthingsstrings.com/Bows/CARE-MAINTENANCE/Bow-Hair-Care-Tips )
The everyday basics of bow care could be reduced to three simple rules: be careful where you set it down, keep it clean, and loosen the hair when you’re not playing. Developing good bow-care habits, plus an occasional examination for wear and tear, should keep your stick in good working order for a long time. Don’t overlook hair care. When tightening and loosening the bowhair, hold the bow with your thumb firmly across the pearl slide while turning the button. This hold reinforces the proper relationship between the frog and stick, reducing wear on the eyelet and the stick.
Simply put, the bow is a stick that holds hair under tension. If you look at the bow from the side, you see a long, gradual curve with the low point roughly near the middle and the high point being the head and frog at each end. That curve is called the camber. It will look slightly different on every bow. As you tighten the bow, the hair moves away from the stick, pulling that curve a little straighter. The camber returns to its relaxed shape as you loosen the hair. Watch as you loosen the hair and you’ll learn to see when all the tension has left the stick. Stop loosening there; the hair shouldn’t be flopping around.
Effects of Heat & Humidity
Always remember to loosen the hair when you’re done. Constant tension will, eventually, pull the camber out of the stick—the bow may seem like it’s lost something in tone or feel. It is possible to have a bow re-cambered by heating the stick and bending it, but this is a delicate and potentially dangerous operation. The heated bow can break, no matter how experienced the bow maker doing the job and the feel may change after re-cambering.
Changes in humidity can play havoc with your bow hair. In fact, your shop may ask where you live or if you will be traveling to another climate when you bring it in for a rehair. They’re not being nosy! Hair that is the perfect length in temperate Seattle, in the western part of Washington, can become short enough to pull the head off if taken to arid Spokane, in the eastern side of the state. Or the same rehair could be too long to tighten the bow during an Alabama summer. This can be a problem especially with string students who get a rehair from their home shop and then take it back to college or summer camp in a different climate.
When the hair seems to lose its grip, becomes too stretched out, or loses too many hairs, especially on one side, it’s time for a rehair. Losing hairs on one side of the stick pulls unevenly on the stick, eventually warping the bow. The straightening requires heating the bow, just like re-cambering.
Broken Hairs are Trying to Tell You Something
If you’re breaking hairs constantly, it means that something about the player-bow-instrument combination isn’t working together. It may be time to consider a different bow, start looking for an instrument that gives you the sound you’re striving for, or to examine your technique.
When you take the bow in for a rehair, the shop will probably examine the bow with you in person to detect any faults that may create a problem during rehairing and to make a note of any pre-existing damage. The repair person may point out a worn thumb leather, a worn eyelet, or other maintenance issues. Have these problems taken care of promptly: they can lead to more serious (and expensive) problems. The luthiers typically do this inspection to protect themselves from liability, but it is also an opportunity for you to ask any questions and learn what the experts see when they look at a bow.
It will help you maintain this bow properly and you’ll learn what to look for when it’s time to shop for another bow.