⁂ These and other chemical processes have been almost completely superseded by the certain and economical process of ELECTRO-GILDING. See Electrotype.
Gilding Amalgam. See Amalgam.
Gilding Liquor. This name has been given to various solutions of gold, and to other liquids employed in gilding. The former are noticed elsewhere. Among the latter are the following:
Deading aquafortis. From mercury, 1 part; aquafortis (sp. gr. 1·33), 3 parts; dissolve, and add of soft water, 7 parts. Used to produce a dead-gold effect. It is applied (diluted) to the articles, before spreading the amalgam over them, in water gilding; or before placing them in the ‘gilding liquor,’ in the chemical processes.
Mercurial solution. From mercury, 10 parts, dissolved in aquafortis (sp. gr. 1·33), 11 parts, and the solution diluted with 25 times its weight of water. Used to moisten the scratch brush before drawing it over the amalgam, in mercurial gilding; also to deaden the gilded surface, by moistening the latter with it, and then exposing the piece to a heat sufficiently high to drive off the mercury.
Gilder’s pickle. From alum and common salt, of each 1 oz.; nitre, 2 oz.; dissolved in water, 1⁄2 pint. Used to impart a rich colour to gold surfaces, especially of trinkets. Its application should not be too long continued, as it dissolves a small portion of the gold. For common purposes it is best used largely diluted with water.
Vermeil, Vermeil coating, Or-molu c. From annotta and salt of tartar, of each 1 oz.; dragon’s blood, 1⁄2 oz.; water, 1 quart; simmer down to about one fourth, add saffron, 20 gr., and when merely tepid, strain through fine muslin into a bottle. Used to give lustre and fire to distemper gilding. A little is floated over the surface with a very soft, flat, camel-hair brush.
Gilding Metal. The metal employed as a base for gilding is usually brass, or a mixture of brass and copper. The following proportions have been recommended:—
1. Copper, 6 parts; brass, 1 part. 2. Copper, 4 parts; Bristol brass, 1 part. 3. Copper, 13 parts; old Bristol brass, 3 parts; tin, 14 parts.
Gilding Powder. Prep. 1. Pure gold, 5 dr.; pure copper, 1 dr.; aqua regia, 10 oz.; dissolve, moisten clean linen rags with the solution, dry them, and burn them to ashes. The latter contain the gold in a state of minute division, and must be carefully collected.