29.5.10

bow rosin, in search of a good combination for the vielle à roue




This is my first attempt to make bow rosin, using original recipes from c.1700. Bow rosin is usually made with colophony and shellac flakes. Colophony is the sap from the pine tree, purified and melted. Shellac is an exudation of an insect that feeds on the sap of trees in India and Thailand, collected, purified and sold in form of flakes of various colors and levels of purity. Here I used orange shellac flakes, which still contain some wax (removed in the white shellac). Gum mastic, a resin obtained from the Pistacia Lentiscus tree in the mediterranean, was added for flexibility. The amount of "drag" that a rosin gives relates to the percentage of Gum Mastic. Therefore I have been adjusting the levels to get the best grip on my boxwood-veneered hurdy-gurdy wheels

The pine rosin is melted, and mixed with the shellac. Mastic is added towards the end. The open flames proved to be a bad idea. But overall the result was worth the try.