TECHNIQUES OF FORGING METAL OBJECTS

This article is devoted to the techniques of forging metal objects of historic interest and it is only part of a thesis on “Techniques of Forging the Works of Art Made of Metal and Methods of Their Identification”. In their endeavour to give the objects the appearance of the authenticity of old works of art the forgers have worked out a number of techniques and ways of producing the fakes. At the beginning of the article the author writes about patina and its importance. For instance, original patina was removed from some objects found in old collections (Greek and Roman bronzes). They were left without patina or, for its preservation, the original patina was covered with an artificial one, which was often dictated by the fashion. And so, in the age of Renaissance works of art made in metal were coated with lacquer or with coloured or black varnish. The author states thus that a disclosure of forged patina does not always mean that the work is not authentic. The next problem discussed by the author is the formation of natural patina on copper, bronze, lead, stannum and iron. An important problem is also a proper knowledge of the composition of minute and vestigial impurities in metals or alloys, which makes it much easier to state, on examination, whether or not the object has been forged. A technique often employed by forgers is the use of old metal, the so-called scrap metal melted into one. However, a very strange composition of impurities is produced in such case. Still another method of forging the metals is a deterioration in the value of the noble metal. This, in the first place, applies to forgeries in numismatics. A separate question is the ways of metal casting employed both by old masters and by forgers by means of “lost wax”, the so-called free hand or mouldings or a galvanoplastie technique. Another well-known and popular mode of forging is the coating of surfaces with noble metals. Still, the most common forms of forging today are the so-called semi-forgeries that constitute a mixture of techniques and alterations of original works of art made in metal and this applies mainly to military accessories