A method is disclosed in which the bare glass fibers are firmly soldered into a solder bath of the splicing device and, after being scored and broken, unsoldered again. To that end, the glass fibers are placed across the solder bath, the solder is heated, and the level of the molten solder is raised above the glass fibers by pressing a slide into the solder trough. The heat supply to the solder bath is subsequently cut off. After the solder has cooled, the glass fibers are firmly fixed therein. To release the fixed glass fibers, the solder is liquefied again. The device for carrying out the method consists essentially of a slotted guide bar, which serves to hold the glass fibers apart, and the solder bath. The latter is a copper block which is thermally insulated from the splicing device and has a projection at one end for attaching a soldering iron.