History of Glass Grinding
First horizontal Grinding benches were used already in the 7th Century BC for processing Glass type objects. The objects found during excavation were partially traces of ground rings.When a work piece is chucked in a lathe-type device or clamped on a turntable and a wood is centered, a pattern develops accordingly. Always two persons were required for processing as per this method.One persons works on the work piece with the tool,and the other turns a type of crank. At first such glass pieces were discovered during excavations from Mesopotamia so far. It is believed that this handicraft had spread from there to Mediterranean.
Then, in later centuries, a small bronze or copper wheel is coated with a mixture of oil and quartz sand is used in the grinding bench. These hard masses cut then the stone or glass and allows formining of engravings. The pre-determined engravings are first roughly mapped as a draft. Accordingly , then, the work piece is held in a rotating round table to generate the engravings. Zinc white is used as the grinding and polishing powder till the end of 19th century. The glass was moistened with Turpentine oil or with diluted Sulphuric acid when drilling etc. to be done in the lathe. Nowadays glass is ground with the help of sand blasting also. Fine sand is blown against the glass by a powerful stream of air. By this method, it is possible to achieve a complete matt finished surface with in a short time. Thus, it is possible to use sand of different grain sizes. More smaller the grain size, finer is the matted surface. The type and style as per the expensive pattern can be actually incorporated in the glass with the help of templates.
Glass grinder, other than producing engravings in the glass, grinds glass ornaments or grinds entire surface smooth. In Middle ages glass grinder is a separate profession by itself. In the current era , the profession of glass worker includes some of the activities of the glass refining and glass design. However Glass refiner and Glass engraver stand as a distinct professional group similar to hollow-and flat glass worker for transparent Art works.Thus, the craftmanship, sense of color, Knowledge in glass styling and the experience in dealing with glass material are prerequisite for successful work. Terms and Definitions in the field of Glass Grinding:
- Cut edges are raw and sharp Glass edges that occurs when cutting the glass.
- Beveled edges: The beveled edges are beveled edges which must be broken by a grinding stone (beveled edges).
- Ground edges, are also fine tuned edges by grinding throughout the entire worked out edge surface.
- Polished edges are refined ground edges by honing and glazed edges.
- Decorative grinding are very special refinements to the glass surface.
Even in Kaufbeuren-Neugablonz there are still some companies who have specialized in grinding of Glass products. Primarily these companies are in grinding glass jewlry stones and then futher in the fashion jewelry. Also the company Schäfer Glass grinds and polishes their own manufactured products. More information can be found in our website under the heading Human.