Symptoms of a Bow in Need of a Rehair
The Bow Won't Tighten Anymore
This is typically one of the main symptoms of a bow in need of a rehair.
Still confused? Here is a basic explanation of how the hair on your bow is tightened every time you use it.
When the bow screw is turned on a violin, viola, cello, or bass bow, the frog is pulled along the interior bow stick mortise (see bow parts listed below)
As the frog slides along the mortise, the bow hair is pulled tighter and tighter against the tension of the bow stick.
When the frog has run out of mortise to slide along, the bow screw can no longer be turned. Bow hair that has stretched with use has not only reached the end of its length, it has also lost the ability to offer a clean sound.
It is important to rehair a bow when it becomes difficult to tighten to improve the sound quality, the play-ability of the bow, and to avoid prematurely wearing out the frog eyelet and bow screw threads.
The Bow is Making a Scratchy Sound
This is typically a symptom of one of two things:1. The player has applied too much rosin.
To determine if there is excessive rosin on a bow, we do a visual inspection of the bow hair. A bow with excessive rosin will have very, very, very
white hair and can tend to create a rosin cloud when the player uses the bow. If the bow hair is still on the shorter side and has been replaced fairly recently, we may recommend playing through some of the built-up rosin to try and preserve the existing bow hair.
However, if the rosin build-up is too excessive, we may have to recommend a rehair to offer a fresh start. 2. The bow needs a rehair.
There comes a time when a player has simply played through the life of the bow hair. With repeated use, the bow hair requires the player to apply more and more rosin to try to replicate the same grip they once had when the hair was new and fresh. This build-up of rosin creates a scratchy sound and the old hair requires more work to use.
With normal use, most bows require a rehair every 6-12 months.
The Bow Hair is Visibly Dirty
This feels like a fairly obvious problem and is often caused by touching the bow hair. Many players rest the hair of their bow against their thumb or finger(s) when carrying their bow or holding it in rest position. The oils and dirt on your hands are the most common cause of this build-up. Avoid touching your bow hair when possible and rehair your bow regularly. (See photo below.)The bow pictured above is an example of a bow with missing and dirty horsehair.
The Bow Hair is No Longer a Flat Ribbon
The most common cause of this problem is missing bow hair. (See photo above.)
With regular use, it is common to break a hair or two off on the bow. Over time, minor hair loss adds up and the hair that once laid as a nice, flat ribbon across the ferrule is now a thin, clump of hair. Once enough hair goes missing, the wood spread wedge which holds the hair in a flat ribbon can fall out.
Bow Hairs are Breaking or Exploding
You may be the victim of bow bugs! Although these critters can cause a nuisance, this problem is easily treated and is something we have discussed in a previous "Notes from the Bench." Click here to learn more about bow bugs