Chasing
Under chasing is meant a form of the metal machining in which not cut the metal, but on a soft surface with hammer and punches driven or pressed , is such that lines and relief plastic forms arise that look similar but softer casts of negative hollow sections, with Edge. By chiselling, a decoration of metallic surfaces is achieved, for example in an item of jewelery , a watch (pocket watch) or weapons (especially in the case of revolvers ).
Derivation of the name
The term comes etymologically from the French ciseau (dt. " Chisel "). As the origin of the name derives, the term was initially not only understood to mean the non-cutting machining of metal, but basically also to mean plastic deformation .
Procedure
The chasing is like driving a cutting deformation of smooth metal surfaces. In contrast, engraving (for example weapon engraving ) is a cutting technique . Chiselling means to drive patterns into metal; that is, to model cold metal.
By using differently shaped punches , but also with tools such as graver , file , chisel and the like, patterns or ornaments are worked into the mostly polished metal surfaces . Chasing creates a new surface: the relief . The metal has to be heated repeatedly between the individual work steps so that it can relax.
The workpiece is placed on a sand cushion or better in a rotatable in all directions Ziselierkugel embedded (a hollow, cast-iron hemisphere with 20-30 cm in diameter) and released, processed from the hand, starting from the back. The hemisphere is filled with chased putty in order to obtain an elastic base . This consists of a mixture of equal parts of black pitch and fine brick flour, to which, depending on the desired suppleness, some beef tallow or beeswax or real turpentine is added to harden. The mass must be elastic and, as required, can be made softer and more pliable by heating. The cooled putty serves as a stable support.
The main tools for chasing are the chasing hammer and punches , chisels and graver. A chaser has dozens of chisels of various shapes and usually over a hundred hallmarks, most of which he has to make himself. There are also a large number of burins that he has to make himself according to his work habits. The engraver chasing, which also requires the tools and techniques of the engraver, uses both working methods. Gun engravings, on the other hand, are only made with chisels and are a specialty.
application
Chasing is a very old technique that was used by the early advanced civilizations from the Inca Age ( Bronze Age ) to create valuable plastic jewelry. Jewelery makers have used this fine and time-consuming technique across all cultural epochs and, depending on the zeitgeist, have created very different pieces such as watches, jewelery and other objects of noble use as well as sacred vessels. High-quality handguns were also often chiseled.
There are three different occupations of chaser: the driving chaser, the casting chaser and the glass mold chaser.
The driving chaser drives reliefs / pictures into a copper sheet, which is embedded in a pitch bath, with predominantly round, polished punches and a chasing hammer. There are whole sculptures / figures that were made from sheet copper and then soldered with tin. The cast chaser works in art casting workshops and processes the bronze there after casting. Here chasing is used to remove remnants of the casting process and to give the casting its final shape.
The cast chaser is the sculptor's cast finisher. Art casts in bronze, silver or gold are reworked and patinated (colored) by the cast chaser as the sculptor / artist imagines it. There are still chasers who have learned this profession and also practice it, mostly in bronze foundries. Chasing is now sometimes done by the artists themselves, who produce metal art objects by working with punches, chasing tools and driving irons.
The glass mold chaser is based in the area around Zwiesel (glass production). He made the metal negative molds for bowls, bowls and mugs. This work was very complex because it had to be done very precisely and cleanly. The negative forms were also worked with chisels and then polished by hand. The job of chaser has officially ceased to exist for a few years. The chaser is now called Metallbildner - Chasing Technique.
See also
literature
- Erhard Brepohl : Theory and Practice of the Goldsmith. 15th enlarged edition. Fachbuchverlag Leipzig in Hanser-Verlag, Munich et al. 2003, ISBN 3-446-22364-9 .
- Manfred Kluge (editing): metal technology. Metal construction and production technology, basic education (= European reference book series for metal professions. ). 9th, expanded edition. Verlag Europa-Lehrmittel, Haan-Gruiten 2007, ISBN 978-3-8085-1139-8 .
- Gert Lindner: The large mosaic book of works. Creative design, materials and techniques. Completely revised edition. Mosaik-Verlag, Munich 1979, ISBN 3-570-06469-7 .