File:Glass blowing forming the body, part2.webm

English: Since 1979 the LWL- Industrial Museum Glashütte Gernheim has provided insight into traditional glass-manufacturing through presentations. The recording one can hear two glass-blowers at work in the production of simple drinking glasses.

The about 1200 C° hot oven melts a mixture of raw materials like sand, limestone and natron into glass-material. The ventilation of the oven is in permanent operation and one can hear its humming throughout the whole production of the glass. By blowing more the hollow space grows larger. By use of the wooden shapers the glass receives a rounder, more even shape, letting the blown in air expand evenly inside the glass. The wooden shapers are kept moist with water so that the glass doesn't burst when blown into. The water cools off the outer skin and provides certain firmness. Then the glass-blower uses a different moist, wooden forming tool to form the glass bottom. The moist newspaper is used for punctual cooling of the glass. The cooling of the blowpipe and the vaporization of the water on the wet forming tools and the moist newspaper generate the typical hissing sound. In the next step the glass-blower uses a certain type of scissors to create a predetermined breaking point. The predetermined breaking point enables a clean separation of the glass and the blowpipe, when a drink opening is formed on the other side of the glass later in the process. The scissors cutting the glass creates a crackly sound.

Sound recordist: Konrad Gutkowski / Jonathan Nicolai Video recordist: Konrad Gutkowski / Jonathan Nicolai

Photo: Konrad Gutkowski / Jonathan Nicolai