Laval University From the SelectedWorks of Fathi Habashi August, 2007 History of Metal Casting Fathi Habashi Available at: https://works.bepress.com/fathi_habashi/438/ History of Metal Casting Fathi Habashi Department of Mining, Metallurgical, and Materials Engineering Laval University, Quebec City, Canada [email protected] metallurgy History of Metal Casting—Part 1 by Fathi Habashi, Department of Mining, Metallurgical, and Materials Engineering, Laval University believe that my work would surely be almost a seed without fruit and that I would fail in that cause which disposed me to satisfy your request I to write and form this work if, while labouring on it, 1 did not tell you of the art of casting, since it is a necessary means to very many ends. It is especially necessary since this art and work is not well known, so that no one can practice it who is not, so to speak, born to it, or who does not have much talent and good judgment. For this reason and also because it is closely related to sculpture, whose arms are the support of its life, it is very highly esteemed… it is a profitable and skilful art and in large part delightful. [BIRINGUCCIO, IN PIROTECHNIA, 1540] Introduction The history of metal casting is the history of metal- lurgy. Metals produced in a furnace are melted and cast to form useful objects, whether a piece of jewelry, an agri- cultural tool, or a weapon. Objects made of gold, silver, copper, bronze, brass, tin, lead, and iron conserved in museums are a testimony to the cleverness of the ancient metal workers. The history of casting is also the history of art since most castings are made by artists. Ancient Egyptian wall paintings give an excellent illustration of the melting and casting of gold and copper. Most of the important Egyptian castings were used for making jew- elry and masks. Copper was traded in the form of large cast ingots. The Colossus of Rhodes is an immense bronze statue Ancient Egyptian wall painting illustrating the casting of copper of Apollo the Sun God and protecting deity of Rhodes, constructed during the period from 292 to 280 BC, which stood at the entrance to Rhodes Harbour. It fell to pieces in 224 BC when an earthquake struck the island. It remained there for centuries until the Arabs gained possession of the island in 672 AD and sold what remained as scrap metal. The description of the statue is known only through writings of the Roman historian Pliny who visited the island in the first century AD. The statue stood about 32 metres high and weighed 300 tonnes. The Etruscans and Romans also cast large bronze statutes. In ancient China, massive bronze vessels were cast dur- ing the Han Dynasty (206 BC to 220 AD). The brilliant age of Japanese bronze founding dates back to the introduction Large statue of the Roman emperor of Buddhism, in the sixth century AD in Nara, the ancient Ancient copper ingot Marcus Aurelius in Rome capital of Japan. Among the Japanese creations of this period was the colossal 380-tonne seated Buddha of Todaiji, consort of Shiva, is the nourishing and life-giving bronze gilded with 440 kilograms of gold. In India, Parvati, the statue dating back to about 950 AD. 72 CIM Magazine I Vol. 2, Nº 5 metallurgy The same technique used for casting large bells in ancient China was later used in It was the church that provided Europe to cast cannons when gun powder the greatest outlet for their skills in bell founding became known around 1250 AD. The fall of to supply bells for the cathedrals and abbeys. Constantinople in 1453 was a turning point in the history of the world; city walls were bombarded by stone balls thrown by huge cannons con- Columbian Mexico, and the Benin civilization in Africa structed by the Turks. During medieval times in Europe, the used this method of casting to produce their artwork in foundry men and smiths produced weapons and armour, copper, bronze, and gold. household utensils and tools, swords, and other imple- ments demanded by the feudal lords. However, it was the In this method, the smith church that provided the greatest outlet for their skills in creates a pattern for the cast- bell founding to supply bells for the cathedrals and abbeys. ing by covering one of the Because of its size and importance, bell founding raised the cores with beeswax and care- casting of metal to the class of a practical art. At the time of fully modelling it into the war, bells were often melted down and made into weapons. desired shape. When the wax form is finished to the artist’s Some medieval technical manuals, such as De Diversibus satisfaction, it is covered in a Artibus (On the Different Arts), the earliest known foundry thick coating of clay. The text, written around 1120 by the German Benedictine monk cores are made to be self sup- Theophilus Presbyter (circa 1070-1125), give detailed porting. This mould is accounts of the tools and equipment used for the gold- allowed to air dry. When a smiths’ work. The invention of movable and cast lead type batch of moulds has been cre- Bronze statue of Parvati, the consort for the printing press in 1450 was an important application ated and is ready for casting, it of Shiva, dating from about 950 AD— of casting. is placed in a fire and heated an example of Indian artistic casting so that the wax melts. The The casting of bells and wax is collected through a runner and can be reused after cannons was described at any foreign matter is removed. The clay moulds are further length by Vannoccio heated to a point where they are sufficiently hard. This per- Biringuccio (1480-1539), mits the pouring of the molten metal without causing the the head of the Papal shell to burst. The moulds are then placed upright on the Foundry in Rome, in his floor and molten brass is poured into the open mould. Soon Pirotechnia, published in after casting, the molds are broken open, the shell knocked 1540, one year after his off, and the final object is cleaned, filed, and polished. death. While at the Paris Coating the wax pattern with layers of clay became known Arsenal, Pierre Surirey de as investment. Saint Remy (1645-1716) wrote a two-volume book Shortly after the Dark Ages in Europe, the industrious The colossal 380-tonne seated Buddha in in 1697 entitled Memoires sculptor and goldsmith Benvenuto Cellini (1500–1571) Todaiji, Japan, gilded with 440 kilograms of gold d’artillerie, which con- began to make use of the lost wax tained valuable informa- method of casting, which he learned tion on casting cannons. The close ties between casting and from the writings of the monk pottery indicate that the two arts must have developed simul- Theophilus. In his autobiography, taneously. It was the potter’s art—the selection and com- Cellini described in detail the casting of pounding of suitable clays, their moulding, and proper fir- his Perseus and the Head of Medusa. ing—that gave the foundry the crucible for handling molten This three and a half ton statue was com- metals. Bells were generally decorated to give them an addi- pleted in 1554 and was unveiled at the tional message or to keep danger away, while cannons were Loggia dei Lanzi in Florence, Italy, where usually decorated with the coat of arms of the owner. it stands to this day. The process was developed to a high degree of excellence, The Lost Wax Process as is attested to by the many finely detailed statues, jewelry, and artefacts The lost wax process dates back thousands of years. The from antiquity. This technique was redis- artists and sculptors of ancient Egypt and Mesopotamia, the covered in 1897 by the dental profession Cellini’s Perseus and Han Dynasty in China, the Aztec goldsmiths of pre- for producing crowns and inlays. CIM the Head of Medusa August 2007 73 metallurgy History of Metal Casting—Part 2 by Fathi Habashi, Department of Mining, Metallurgical, and Materials Engineering, Laval University Casting of Bells associated bells with pagan rites and beliefs, while in Judaic The development of the bell-casting skill ushered in the practice, the ram’s horn and the metal trumpet have always Bronze Age around 3,000 BC. Bells were frequently buried in been used. The casting of large temple bells in China the tombs of Chinese royalty and noblemen, but not in reached its zenith during the Ming dynasty (1368-1620). ancient Egyptian tombs. As metal-casting techniques The largest such bell, cast during the reign of the Emperor improved, the size of bells increased; bells weighing many Yon-gle (1403-1424), weighed 52 tonnes. tonnes were suspended in front of temples and palaces. Both Because bells were utiliezed so much in pagan cultures, drums and bells announced the time of day and warned of Christendom initially disapproved of them. It was not fires, floods, or an approaching enemy. The ancient Chinese until the second century that the bell was adopted as the were also successful in controlling the pitch of bells by con- symbol of preaching the gospel and used as a call to trolling the relationship between size and thickness. assemble. The popularity of bells increased enormously in Chinese bells were cast in a variety of forms. In addition the ninth century after being promoted by Charlemagne. to stationary bells, small ornate hand bells with clappers One of the earliest works describing the casting of bells were used in temple ceremonies.