Zarelon Notes for the Luthier

Zarelon vs. Horsehair in terms of rehairing

There is very little difference in rehairing a bow with Zarelon and rehairing a bow with horsehair.

Cyanoacrylate (super glue) works very well to help secure the knots at the ends of the hank.

The gauge of Zarelon is thicker than horsehair by a significant amount.  I use the same tool for measurement for both the Zarelon and the horsehair to measure the amount of Zarelon needed for an individual bow.  I tend to use the exact amount with Zarelon because I do not lose any strands of Zarelon in the process.  Typically with horsehair I estimate more than is actually needed on the bow, because I lose a few hairs due to the length and inconsistency of horsehair.  There is no need to over estimate the amount of Zarelon because of how tough it is.

The spreader wedge in the tongue of the frog needs to be a bit more precise with Zarelon.  Horsehair compresses quite a bit because it’s an organic material.  Zarelon doesn’t compress much and it can be a little finicky trying to get an even ribbon across due to there being less hairs.  My advice, is to make sure the frog tongue is very clean and shaped correctly, and when fitting the wedge, carve it slightly thicker than what you’d normally estimate.

The luthier has a little more leeway with figuring the length of the hair from frog to tip with Zarelon.  Horsehair has to be within a millimeter to fit it correctly with the frog at the full forward position.  As long as you estimate the length loosely with Zarelon you can even up the hairs easily with a heat gun on its lowest setting.  Zarelon responds to a heat gun quickly and can be done several times as long as you keep the heat gun a good distance from the Zarelon.  I do not recommend using a heat gun on horsehair as it has a tendency to dry out and doesn’t respond well.  This is one of the most difficult things to get right when rehairing, but in my opinion Zarelon makes this step much easier, no matter what your method is.

There is an elastic trait to Zarelon that horsehair does not share.  Horsehair tends to stretch out over a matter of six months of use depending on how much the player practices.  Zarelon has an initial stretch the luthier can remove with just an extra step.  Instead of rosining the bow when you are finished, tighten the bow enough for it to be played, take something clean and round, and move it up and down the length of the Zarelon as if you were rosining the bow.  If done correctly, you will have a few loose hairs to even up with the heat gun.

Justin McElravy

-Bow Specialist at Peter Zaret & Sons Violins