Zinc casting

from Wikipedia, the free encyclopedia
Gilded cast zinc arches in the Niobidensaal of the Neues Museum in Berlin

Zinc casting (cast zinc in various alloys ) is a term for a material or an artistic technique in architectural ornamentation and sculpture, mainly from the mid-19th century.

history

The discovery by Sylvester and Hobson in 1805 that zinc, when heated to 100 ° C, loses its brittleness, contributed significantly to the naturalization of zinc. However, zinc production only became possible after the zinc distillation was developed by William Champion in Bristol, by Christian Ruberg in Silesia and by Jean-Jacques Dony in Liège (simultaneously and independently) at the beginning of the 19th century . The previous problem was that zinc was not produced in liquid form during smelting, but in the form of zinc vapors, which combined with atmospheric oxygen to form powdered zinc oxide. The resulting zinc vapors were then condensed in the absence of air during the zinc distillation (zinc reduction furnace).

As early as 1900, small statuettes made of cast zinc were popular in middle-class households, for the manufacture of which the zinc-aluminum alloy zamak was predominantly used (around 4% aluminum , with additions of up to 1% copper and around 0.05% magnesium ). Zamak is reminiscent of bronze in color and luster . The Stolberg company Kraus, Walchenbach & Peltzer offered over 5000 different models of zinc ornaments in their sample catalog.

Larger-volume zinc ornaments were produced using the so-called "fall casting process": after the hot liquid zinc was poured into a cold metal mold, the zinc melt solidified on the contact layer with its cold wall. If the mold was overturned immediately, the remaining melt, which was still liquid inside, flowed off and a hollow body resulted, which had the desired shape on the outside.

At the beginning of the 19th century there was fierce competition in the zinc smelters of Upper Silesia due to overproduction and the resulting ruinous price decline for this metal.

Since "zinc casting is much cheaper than sandstone work and iron casting [turns out] and at the same time is quite durable" and to support the zinc industry, the innovative Prussian architect and secret building officer Karl Friedrich Schinkel used zinc as a material, especially for large-format decorative elements on the buildings he designed a. However, until the end of the 1830s, zinc casting was only used for the production of these architectural decorations.

In 1826 the "Association for the Promotion of Industrial Work in Prussia" offered a price for the discovery of a mass application of zinc, and as a result of this suggestion, in 1833 Krieger showed that zinc could also be used for hollow castings of all kinds. In 1837 Moritz Geiß , a Berlin iron foundry owner, developed the had been experimenting with the zinc casting technique since the end of the 1820s, a process to produce fully plastic figures from zinc cast.

The Rubenow monument in Greifswald: the largest free-standing neo-Gothic monument in Germany made of galvanically bronzed cast zinc

These circumstances and Schinkel's protection soon led (especially in Berlin) to the production of numerous (often gold-plated , sometimes also bronzed by galvanic copper plating ) architectural pieces, ridge galleries, columns, ornaments, chandeliers, street signs and figures (simulating fine natural stone by sanding) from cast zinc.

Zinc casting became popular in architecture, especially in historicism, in the middle of the 19th century, especially for ornaments and cladding of iron supporting structures, since experience shows that finer ornaments on such large construction parts result from the [iron] casting very impure and imperfect.

Cast zinc was even used as a substitute for filigree wood carvings in the construction industry. The decorative capitals of the window beading strips of Wilhelminian style Berlin houses are made of this material in large quantities, which is why it is being restored today for restoration purposes.

In small sculptures, zinc casting served as a substitute material for the more expensive bronze casting, albeit a fragile and short-lived one. The imitating galvanic copper plating or bronzing sometimes had to be renewed on this material. Zinc cast was even used for building meter-high objects, such as monumental vases and statues.

Gold- plated cast zinc was also common in the manufacture of pendulum clocks . The lamp industry used zinc casting for the mass production of lamp bases.

From Berlin, the new process quickly spread across Germany and beyond.

The famous castles of King Ludwig II in Herrenchiemsee and Linderhof are richly decorated with figures and architectural ornaments made of cast zinc, which was also colored, sanded or gilded.

Important zinc foundries were Moritz Geiß (produced copies of ancient sculptures and architectural ornaments in classical and contemporary styles since around 1840) and Siméon Pierre Devaranne in Berlin.

In the years after the Second World War, many building ornaments made of cast zinc disappeared because the non-ferrous metal zinc was in short supply and reached a high price.

Today around 6% of the zinc used is processed in the form of alloys in zinc casting (almost exclusively zinc die-casting).

Examples of use in architecture and sculpture

(small selection)

Cast zinc relief in marble look: “Art instructs industry and applied arts” by August Kiß in the western tympanum of the Neues Museum in Berlin, 1862
Busts made of cast zinc in the Heldenallee of the Heldenberg memorial.

Zinc die cast

Matchbox fire engine made of die-cast zinc

In contrast to the earlier fall casting process, this process, which is almost exclusively used today, does not move the hollow mold, but presses the liquid zinc alloy into the fixed mold under pressure.

Many toys, for example, the famous Matchbox - model cars and model railway vehicles, as well as commodities such as zippers were, and are in die-cast zinc articles made of today often associated with plastic parts.

Damage and restoration

Pure zinc is a very shiny and relatively corrosion-resistant metal (use of galvanized watering cans, buckets, tubs, etc.).

Under the influence of humidity, a gray patina of zinc carbonate forms , which initially offers a certain degree of protection against corrosion.

Under certain conditions, white rust can form on zinc surfaces as a corrosion product.

Historic cast zinc objects, especially when they are exposed to changing temperatures, cold and damp weather, are often attacked by zinc corrosion , depending on the production and processing characteristics ( soldering of seams) , with blooms and blisters as well as stress cracks appearing on the surface . In principle, this process cannot be stopped.

A joint project between the Bavarian State Office for Monument Preservation and the Prussian Palaces and Gardens Foundation Berlin-Brandenburg , funded by the German Federal Environment Foundation , was set up to research the possibilities of conservation .

literature

Historical literature, master works

  • Simeon Pierre Devaranne (Ed.): Plastic cast zinc works based on drafts and models by proven builders, sculptors and draftsmen of our time; as well as formed from ancient sculptures and older and newer works of art and executed in the zinc foundry for arts and crafts , 6 volumes, Berlin: Sachse, 1847ff.
  • Moritz Geiss (ed.): Zinc cast ornaments based on drawings by Schinkel, Stüler, Persius, Schadow, Strack, Knoblauch, Stier and others, as well as statues and sculptures based on ancient and modern models, executed and cast in the zinc foundry for architecture by M. Geiss in Berlin: in exact illustrations according to the scale, for use by architects, building craftsmen and all those who are eager to ornament , 21 volumes, 1st edition Berlin: Lüderitz, 1844–1852, 2nd edition Berlin: Ernst & Korn, 1863
  • F. Kahle: Architectural and plastic decorations, ornaments, church equipment, statues and sculptures based on drawings by Stueler, Persius, Hesse, Strack, v. Arnim, Haeberlin, Gottgetreu including acroteries, palmettes, rosettes, vases, capitals, columns, modelons, consoles, grids, reliefs and monuments in cast zinc made by F. Kahle in Potsdam , 3 booklets, 1856
  • M. Czarnikow: model views and price information of the art stone foundry and zinc casting establishment of Czarnikow in Berlin , Berlin, 1865
  • The art industry in Berlin: a collection of the finest products in metal, clay, wood and stone, from local factories and workshops: drawn from the original. Delivery 1, containing cast zinc ornaments from Mr. Lippold's factory , Berlin, 1856
  • M. Le Brun, Theodor Raetz: M. Lebrun's manual for plumbers and metal goods manufacturers as well as for workshops for gas and water supply systems: containing the description and processing of metals, the geometric sectional drawings, the explanation of the various work and tools; the principles of lighting art; Images and descriptions of the latest lamps, tea and coffee machines, kerosene cookers, lanterns, bird farmers, vases, fountains, acroteries, consoles, balustrades, skylights and other building decorations made of cast zinc or pressed zinc sheet ... [Manuel du ferblantier et du lampiste , ou l'art de confectionner en fer blanc tous les ustensiles possibles (Ger.)], 7th, completely redesigned, with the latest inventions and improvements, probably edition, Weimar 1876. Reprint: Hanover: Edition "libri rari" in Verl. Th. Schäfer, 1997, (Neuer Schauplatz der Künste und Handwerke, 53; Classical textbooks and model books for practitioners, 17), ISBN 3-88746-367-6
  • Munich metal ornaments and lightning rod article factory Lorenz Sporer: Sample book on architectural and decorative metal ornaments made of zinc, copper, sheet brass, lead and cast zinc , 4th edition, Munich, around 1905. Reprint: Munich, around 1987

Newer literature

  • Sabine Hierath: Berliner Zinkguss: Architecture and Visual Art in the 19th Century , (Letter Schriften; 15), Cologne: Letter Foundation, 2004. Zugl .: Berlin, Techn. Univ., Diss., 2000. ISBN 3-930633-14 -0 .
  • Sabine Hierath (Scientific Director and Catalog Editing), General Directorate of the Prussian Palaces and Gardens Foundation, Berlin-Brandenburg (Ed.): Material and possibility: 19th century zinc casting in Potsdam; Exhibition in the Orangery in Sanssouci Park, June 21 to June 17, 1997 , Berlin-Brandenburg: General Directorate of the Prussian Palaces and Gardens Foundation Berlin-Brandenburg, 1997.
  • Peter Mottner (Ed.): Zinc casting: the conservation of monuments made of zinc. Joint project of the Bavarian State Office for Monument Preservation and the Prussian Palaces and Gardens Foundation Berlin-Brandenburg, funded by the German Federal Environment Foundation, Osnabrück , (workbooks of the Bavarian State Office for Monument Preservation; 98), Munich: Lipp, 1999, ISBN 3-87490-695- 7 .
  • Horst Ende: From a deceptive appearance: some marble, sandstone or bronze sculptures are simply made of cast zinc - an overview , In: Mecklenburg-Magazin: regional supplement of the Schweriner Volkszeitung, Schwerin: Landesverl.- u. Druckges., 31, 2000, p. 21.
  • Josef Riederer , German Federal Environmental Foundation (Ed.): Corrosion damage to zinc sculptures. Report on the research project of the Deutsche Bundesstiftung Umwelt, Osnabrück , (Berlin contributions to archaeometry; 14), Berlin, Staatl. Museums zu Berlin Preußischer Kulturbesitz [including], 1997, pp. 5–210.
  • Nicola Vösgen: Studies on Berlin zinc casting of the 19th century. From the beginnings to around 1860 , in: Berlin contributions to archaeometry, vol. 14, Berlin, Staatl. Museums zu Berlin Preußischer Kulturbesitz [including], 1997, pp. 211–317.
  • Nicola Vösgen: Berlin zinc casting of the 19th century, catalog , in: Berlin contributions to archaeometry, Bd. 14, Berlin, Staatl. Museums zu Berlin Preußischer Kulturbesitz [including], 1997, pp. 319–487.
  • Walter Jahn: zinc casting in the 19th century and its use for pendulum clocks , in: Jahresschrift Deutsche Gesellschaft für Chronometrie, Stuttgart, 38, 1999, pp. 65–71.
  • Elisabeth Vaupel : zinc casting. Surrogate material in art and architecture . In: Praxis der Naturwissenschaften - Chemie in der Schule, 53, 2004, pp. 16-18.
  • Sabine Spindler: The Queen was also enthusiastic: zinc casting had its heyday between 1840 and 1870 , in: Weltkunst, 75, 2005, No. 12, pp. 56-60.
  • Heinrich Fendel, Christina Achhammer, Günter Siebert: Zinc cast figures of the 19th century in Lower Saxony and their versions , in: Reports on the preservation of monuments in Lower Saxony, 21, 2001, pp. 142–145.
  • Peter Mottner, Jörg Freitag, Wolf-Dieter Kaiser: Monuments made of zinc casting: Manufacturing processes and forms of corrosion , in: Restauro, 103, Callwey Verlag, Munich, 1997, pp. 104-107.
  • the same: Monuments made of cast zinc: Preserving coatings in the laboratory test , in: Restauro, 103, 1997, pp. 166-171.
  • Jörg Freitag: Signs of corrosion on cast zinc objects from the 19th century , in: Technisches Kulturgut - Protection of metals against atmospheric corrosion, AdR series of publications on restoration and excavation technology (Ed .: R. Wihr and K. Götz), Consortium of Restorers, Volume 1, 1994, pages 31-34.

Footnotes

  1. ↑ Karl Friedrich Schinkel in a letter to one of his clients, Count Redern of October 6, 1829. In: Paul Ortwin Rave : Karl Friedrich Schinkel, Berlin 3rd part , Munich / Berlin, 1981; Page 230
  2. ↑ Berlin and its art treasures. The royal museums in Berlin: A selection of the most exquisite art treasures of painting, sculpture and architecture in the northern German metropolis presented in a series of the most excellent steel engravings with explanatory texts. Payne, Leipzig / Dresden 1855, pp. 215-251.

Web links