Show repairing hard rubber TIB the bureau of it standards nya that hut hard ruller rubber may mayhe lie joined by a bond of if new hurd rubber A cement to Is pre ire jhirad ty by adding one purt part of wid und three parts of crude rubber to fit ty parts 0 of colbun and three arts of alcohol leeral Sec ril ampil of the cement ure are applied to the hie broken parts these bre are finally joined ono anti neld under pressure lire asure ut at a temper liture of degrees 0 J for four bourse fioura A mixture of parts of gutta herclia hilo anil bitumen dissolved in n anny also lie be used V to cement the b broken portions |