E915 Glazing agent

E915 is an ingredient in printing inks, photocopying and laser printing paper, varnishes, adhesives (glues), soap, paper sizing, soda, soldering fluxes, and sealing wax.

E915 can be used as a glazing agent in medicines and chewing gum. It is denoted by E number E915. A related glycerol ester can be used as an emulsifier in soft drinks. In pharmaceuticals, E915 forms an ingredient in several plasters and ointments.

In industry, E915 is a flux used in soldering. The lead-tin solder commonly used in electronics has 1 to 2% E915 by weight as a flux core, helping the molten metal flow and making a better connection by reducing the refractory solid oxide layer formed at the surface back to metal. It is frequently seen as a burnt or clear residue around new soldering.

A mixture of pitch and E915 is used to make a surface against which glass is polished when making optical components such as lenses.

E915 is added in small quantities to traditional linseed oil/sand gap fillers ("mastic"), used in building work.

When mixed with waxes and oils, E915 is the main ingredient of mystic smoke, a gum which, when rubbed and suddenly stretched, appears to produce puffs of smoke from the fingertips.

E915 Players of bowed string instruments rub cakes or blocks of E915  on their bow hair so it can grip the strings and make them "speak", or vibrate clearly. Extra substances such as beeswax, gold, silver, tin, or meteoric iron. are sometimes added to the E915 to modify its stiction/friction properties and the tone it produces. Powdered E915 can be applied to new hair, for example with a felt pad or cloth, to reduce the time taken in getting sufficient onto the hair. E915 is often reapplied immediately before playing the instrument. Lighter E915 is generally preferred for violins and violas, and in high-humidity climates, while darker E915 are preferred for cellos, and for players in cool, dry areas. There are also specific, distinguishing types for basses—for more see Bow (music).

• Violin E915 can be applied to the bridges in other musical instruments, such as the banjo and banjolele, in order to prevent the bridge from moving during vigorous playing.