The gilding term includes a number of decorative techniques for applying a fine gold leaf or dust onto a solid surface such as wood, stone, or metal to give a thin layer of gold. The object of gold is also described as "gold". Where metal is gilded, it is traditionally silver in the West, to make silver-gold (or vermeil ) objects, but gold-bronze is commonly used in China, and also called ormolu if it is Western. Gilding methods include hand and glue applications, chemical plating, and electroplating, the latter also called gold plating. The Parcel-gilts objects (part of gold) are only plated on some surfaces. This can mean that all the inner parts, and no outer parts, of similar gilded saucers or vessels or patterns or drawings are made using a combination of gold and gold fields.
Video Gilding
Origins dan sebarkan
Herodotus mentions that the Egyptians gilded wood and metal, and many such items have been excavated. Certain ancient Greek sculptures of great prestige are chryselephantine, that is, made of gold (for clothing) and ivory (for meat); This however, was built with gold sheets on a wooden frame, not gilded. Extensive ornamental plating is also used in the ceiling coffers of Propylaea. Pliny the Elder tells us that the first plating seen in Rome was after the destruction of Carthage, under the censorship of Lucius Mummius, as the Romans began to gild their temple and palace ceiling, the Capitol became the first place where this process took place. used. But he adds that the luxury of advancing them so quickly that in a very short time you may see all, even private and poor people, gilding the walls, vaults, and other parts of their dwellings. Because of the comparative thickness of the gold leaf used in ancient plating, the traces are still very bright and dense. The metal-metal flame returns at least to the 4th century BC, and is known to Pliny (33,20,64-5), Vitruvius (8,8,4) and in the early medieval period to Theophilus (De Diversis Artibus Book III).
In Europe, silver-gold is always more common than gold-bronze, but in China it has instead occurred. The ancient Chinese also developed a porcelain plating, which was later taken by Frenchmen and other European pottery.
Maps Gilding
Process
Modern plating is applied to many and varied surfaces and by various processes; which is used in modern technology described in gold plating. More traditional techniques are still an important part of vandalism and sometimes still used in general woodworking, work-cabinet, decorative painting and interior decoration, bookbinding, and ornamental leather work, and in decoration of pottery, porcelain and glass.
Mechanical gilding
Mechanical gilding includes all operations in which the gold leaf is prepared, and the process of mounting the gold mechanically to the surface. Techniques include combustion, water plating, and oil plating used by woodcarvers and gilders; and home decorator plating operations, sign painter, bookbinder, paperstainer and several others.
Polished iron, steel and other metals are mechanically plated by applying a gold leaf to the surface of the metal at a temperature below the red, pressing the leaves with a polish, then reheating as additional leaves may be placed. This process is completed with cold burning.
"Coating" or folding or hammering on gold foil or gold leaf is the simplest and most ancient method, and is mentioned in the Odyssey Homer (Bk vi, 232) and the Old Testament. The Ram in a Thicket about 2600-2400 BC from Ur used this technique on the wood, with a thin layer of asphalt underneath to help adhesion.
The next progress involves two simple processes. The first involves a gold leaf, which is gold that is hammered or cut into a very thin sheet. Gold leaves are often thinner than standard paper at the moment, and when held with semi-transparent light. In ancient times it was usually about ten times thicker than today, and probably half in the Middle Ages.
If gilding on canvas or on wood, its surface is often first coated with gesso. "Gesso" is a substance made from gypsum or fine lime mixed with glue. Once the gesso coating has been applied, allowed to dry, and smoothed, it is re-wet with a size made of rabbit and water skin glue ("water plating", allowing the surface to then be glazed into a mirror-like finish) or boiled linseed oil mixed with litharge ("oil plating", which is not) and gold leaf layered and allowed to dry. Gilding on canvas and parchment is also sometimes used whipped beaten egg whites ("glair"), chewing gum, and/or Armenian pillars as a measure, although egg whites and chewing gum become brittle over time, causing the gold leaf to crack and loose , and sometimes honey is added to make it more flexible.
Another gilding process involves the use of gold as a pigment in paints: the artist grinds gold into a fine powder and mixes it with a binder. Then gold is applied in the same way as paint. Sometimes, after painting gold or painting gold, the artist will heat the portion enough to melt some gold, ensuring a flat layer. These techniques remain the only alternative for materials such as wood, leather, vellum pages of illuminated manuscripts, and gold-edged stock.
Chemical plating
Chemical plating includes processes in which gold is at a certain stage of a chemical combination. These include:
Cold plumbing
In this process gold is obtained in a very fine division, and is applied mechanically. Cold plates on silver are made with gold solution in aqua regia, applied by dipping linen into solution, burning it, and rubbing black ash and weight on silver with a finger or piece of leather or cork.
Wet placement
Wet plating is done by using an aqueous solution of gold (III) chloride in aqua regia with twice the ether quantity. The liquid is restless and allowed to rest, to allow the ether to separate and float on the acid surface. The whole mixture is then poured into a separating funnel with a small hole, and allowed to rest for some time, when the acid is released from the bottom and gold is dissolved in a separated ether. Ether will be found to have taken all the gold from the acid, and can be used for iron buffer or steel, whose purpose is polished metal with fine emery and wine spirits. Ether is then applied with a small brush, and when it evaporates it stores gold, which can now be heated and polished. For a small fine image, a fine pen or brush can be used to lay on an ether solution. Gold (III) chloride can also be dissolved in water in an electric coating where gold is slowly reduced out of the solution onto the surface for plating. When this technique is used on a second glass surface and supported with silver, it is known as the "Angel Angels".
Flame ignition
Fire-plating or Washing-Washing is the process by which gold amalgam is applied to the metal surface, mercury is further evaporated, leaving a gold or amalgam film containing 13 to 16% mercury. In the preparation of amalgam, gold must first be reduced to a thin slab or grain, which is heated red-hot, and thrown into a heated mercury before it begins to smoke. When the mixture is stirred with an iron rod, gold is completely absorbed. The proportion of mercury to gold is generally six or eight to one. When the amalgam is cold, it is squeezed through the chamois skin to separate the excessive mercury; gold, with about twice the weight of mercury, lags behind, forming a yellowish silver mass with the consistency of butter.
When the metal to be gilded is forged or pursued, it must be covered with mercury before amalgam is applied, that this may be more easily spread; but when a plain metal surface, amalgam can be applied directly. When no such preparations are applied, the surface to be gilded is simply bitten and cleaned with nitric acid. Mercury deposits are obtained on metal surfaces with mercury, mercury (II) nitrate, nitric acid which invades metals used, and thus leaves free metal mercury films.
The same amalgam is dispersed on a prepared metal surface, mercury is then sublimated by heat sufficient for that purpose only; because, if too large, part of the gold can be moved, or it may run together and leave some metal surfaces. When the mercury has evaporated, which is known by the surface has completely become a dull yellow color, the metal must undergo another operation, where a fine gold color is given to it. First, the gold surface is rubbed with an early brass wire brush, until the surface is smooth.
It is then covered with a gilding candle , and again exposed to fire until the candle burns out. The gilding candle consists of beeswax mixed with the following substances: red ocher, verdigris, copper scales, alum, vitriol, and borax. With this operation the color of plating is getting higher, and the effect seems to be generated by the perfect disposal of some of the mercury remaining after the previous surgery. The gold surface is then covered with potassium nitrate, alum or any other salt, milled together, and mixed into a paste with water or weak ammonia. The covered metal part is exposed to heat, and then quenched in water.
With this method, the color is further enhanced and closer to gold, perhaps by removing copper particles that may be present on the gold surface. This process, when done skillfully, results in a great unity of solidarity and beauty, but because of the exposure of the workers to the windy smoke, it is very unhealthy. There is also a lot of loss of mercury to the atmosphere, which brings very serious environmental problems as well.
This method of plating metal objects was previously widespread, but was not used because of the danger of mercury toxicity known. Because firing fires requires mercury to evaporate to dispel mercury and leave gold on the surface, it is very dangerous. Inhaling the vapors produced by this process can quickly produce serious health problems, such as nerve damage and endocrine disorders, because inhalation is a highly efficient route for mercury compounds to enter the body. This process has generally been replaced by gold electroplating on a nickel substrate, which is more economical and less dangerous.
Depletion Depletion
In depletion depletion, the subtractive process found in the Mesoamerican Pre-columbian, the article is made with various techniques of copper and gold alloys, which are named after the Spaniards. The surface is scratched with acid, producing a porous gold surface. The porous surface is then hardened, resulting in a shiny gold surface. The result deceived the conquerors into thinking that they had a very large amount of pure gold. The result surprised modern archaeologists, because at first the pieces resembled articles that were electroplated. Keum-boo is a special technique of silver plating using depletion depletion.
Ceramics
Decorative ceramic plastering has been done for centuries, with golden immortality and brightness appealing to designers. Both porcelain and earthenware are generally decorated with gold, and in the late 1970s it was reported that 5 tons of gold is used every year for decorating these products. Some of the wall tiles also have gold decorations. Application techniques include spraying, brushing, milkfish machines, and direct or indirect screen printing. After the application of decorated goods is fired in a kiln to blend gold into glaze and thus ensure its immortality. The most important factors affecting the quality of the coating are the applied gold composition, the surface state before the application, the thickness of the coating and the ignition conditions.
A number of different shapes and compositions are available for applying gold to ceramics, and these include:
- Acid-scented plating - developed in the 1860s in Mintons, Stoke-on-Trent, and patented in 1863. Glass surfaces, usually narrow borders, are transfers printed with wax resistant, after the glaze is scratched with dilute hydrofluoric acid prior to the gold application, after which the lifting element of the design is selectively rubbed to provide a bright and matte surface; the process demands great skills and is used for decorating only the highest class equipment.
- Bright Gold or Liquid Gold is a gold sulphoresinate solution along with other metal resinate and bismuth based flux. This is very bright when taken from the decorative kiln and requires a bit more processing. This form of plating was discovered or at least repaired by Heinrich Roessler. The rhodium compound is used to increase binding to the substrate.
- The Best Gold or Gold Gold is applied to the warehouse as a golden powder suspension in volatile oil mixed with lead borosilicate or bismuth based flux. This type of gold decoration is blunt as taken from the kiln and requires burning, usually with agate, to remove the color. As the name suggests it is considered to be the highest quality of the gold decorations. A reported solvent-free gold composition comprises 10 to 40% gold dust, 2 to 20% polyvinylpyrrolidone, 3 to 30% aqueous acrylic resin and 5 to 50% water.
See also
- Embossing (disambiguation)
- French Crown Court Clock
- Gilded Age
- Gilding metal - gold impersonation
- Enjoy the spirit
- Hot stamping
- Metal leaves
References
This article incorporates text from publications now in the public domain: Ã, Chisholm, Hugh, ed. (1911). "Gilding". EncyclopÃÆ'Â|dia Britannica . 11 (issue 11). Cambridge University Press. pp.Ã, 13-14.
Further reading
- Carboni, Stefano; Whitehouse, David (2001). Glass from the sultans. New York: Metropolitan Museum of Art. ISBNÃ, 0870999869
- Shretha, Sukra Sagar. "Gold Plating (Traditional Crafts in the Kathmandu Valley)." Ancient Nepal - Journal of the Department of Archeology , No. 128-129, February-May 1992, pp.Ã, 5-9. [Detailed explanation of the traditional flame-lighting techniques in Nepal.]
External links
- Isaac H. Walker, Gilding Process and Bronzing Photo Frame 1884
- The Gilders Society - the art of plating
- History of plating
- Extensive compilation of depletion plating techniques
- How to gild oil on the frame above the acrylic gesso
- Movies about firebombing in Nepal
Source of the article : Wikipedia
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