Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Coating Metals
Iron castings may be coated with gold or silver by first cleaning and then boiling, in a porcelain vessel, containing water 12, muriatic acid (sp. gr. 1.2) 1 1/2, iron vitriol 2, zinc 1, mercury 12. A layer of mercury is soon deposited on the iron, upon which the gold amalgam may be distributed. For silvering, the iron must be first coated with copper, and the silver applied in the leaf or by means of amalgam. See ZINC COATING; TINNING; SILVERING; GILDING.