FIELD: application of coats made liquid organic compounds on fibers followed by hardening to form solid protective organic coats on fibers; application of coats on glass light conduits. SUBSTANCE: proposed method consists in continuous drawing fiber through mass of liquid covering compound followed by removal of excessive compound from fiber and hardening of liquid compound forming solid protective layer. Atmosphere surrounding the fiber in are where it is introduced into liquid compound contains effective amount of helium which reduces formation of bubbles in solid protective layer. Device proposed for application of coat includes units for forming fiber, units for application of liquid covering compound on fiber, units for forming surrounding atmosphere containing helium and units for hardening of liquid compound after escape of fiber from liquid compound applying units. Units for forming helium-containing surrounding atmosphere form such atmosphere in area where fiber is introduced into liquid covering compound. Provision is made for avoidance of forming helium- containing atmosphere in hardening units. EFFECT: reduced bubbling in solid coat. 11 cl, 5 dwg
