Gilding on Silver, or Grecian Gild ing.—Dissolve equal parts of sal am moniac and corrosive sublimate or bi chloride of mercury, in nitric acid, and dissolve a suitable amount of gold in this solution. Evaporate the ex cess of acid with gentle heat until the mixture is as thick as cream. When the gold is dissolved, brush the silver articles with the mixture, which will turn them black, but on exposing them to a red heat the mercury will be driven off in the form of vapor and the gold will remain.
Or dip the articles in salt water, and rub them with ashes of linen rags previously dipped in a solution of gold in aqua regia.
Or dip the articles in the solution of gold.
To Color Gilding. — To 1 pint of water add 4 ounces of pure saltpeter, 2 ounces of alum, and 2 ounces of common salt. Apply to gilt articles with a brush to improve the color.
Or cover the articles with a mix ture of wax, verdigris, and blue vitriol, expose to a red heat, and polish.
Or boil the articles in a solution of equal parts of common salt and cream of tartar.
Gold Powder for Gilding. — Mix gold leaf with honey or with a solu tion of gum arabic in water, and grind in a mortar until the gold is finely powdered. Dilute the mixture with water and pour it off from the sediment, or wash the gold on filter paper, and dry.
Or dissolve pure gold or gold leaf in aqua regia, and introduce a piece of copper to precipitate the gold. • Or add a little sulphate of iron.
If copper is used, mix the sediment in distilled vinegar, wash by pouring water over it on filter paper, and dry. This is a much finer powder than can be prepared by grinding in honey.
Size for Gilding on Glass or China. —Dissolve ounce of isinglass in 4 ounces of boiling water. When dis solved, cool and add 2 ounces of al cohol. Mix gold powder with borax in a thick solution of gum arabic dis solved in water. Dip the glass in the size, and paint or trace the design by means of a camel's-hair brush. Bake the articles in a hot oven until the borax is melted, when the gold will be fixed on the glass.
Or paint or trace the design in a size of copal varnish. Dissolve with gentle heat 1 ounce of copal in 1 ounce of boiled linseed oil, and thin with oil of turpentine until the solu tion can be freely applied with a brush. Heat the glass as hot as it can be handled, paint the design in the varnish, and lay on a piece of gold leaf. When dry, brush off the superfluous leaf, which will not stick to the part of the glass not varnished, and when cold burnish as usual.
To Remove Gilding on Glass or China. — Mix soft water, 1 ounce; acid, 1 ounce; common salt, I ounce; sal ammoniac, ounce. Bring the mixture to a boil, and put the articles in it or apply it to them with a stiff brush.
To Handle Gold Leaf.—Wax smooth sized paper and slip pieces between the leaves of the book of gold leaf, pressing each piece smoothly with the hand so that the gold leaf will be brought in contact with the waxed surface. Held in this way the gold leaf will not fall or be blown away by a draught, however strong.
Oil Gilding on Wood.—First apply to the wood two or three coats of boiled linseed oil and carbonate of lead. This fills the pores and gives a smooth surface. Dry thoroughly and apply a thin coat of gold size, con sisting of red oxide of lead ground in boiled linseed oil, which should be as thick and hard as possible. Thin with turpentine and apply with a brush. Let stand about twelve hours, or until nearly dry. Then apply the gold.
To handle the gold leaf, make d. cushion of several thicknesses of flan nel cloth, tack it on a piece of wood, and cover it tightly and smoothly with chamois skin. On this lay the sheet of gold, and with a blunt pallet knife or reed cut it into strips the width of the wood. Take up these strips on the bristle points of a fine brush, ap ply them, and smooth them gently with a wad of absorbent cotton. So continue, and as the size sets brush off the last particles of gold leaf with a camel's-hair brush. Let stand two or three days to dry completely. This method is chiefly useful for out-of door work as the gold leaf cannot tar nish and is not injured by changes of weather, exposure to the air, or mois ture.
For inside work, as picture frames which require burnishing, boil down to a stiff jelly pieces of white leather, as an old kid glove or parchment clip pings, and apply a thick coat with a brush. Mix with this size a little fine plaster of Paris or prepared chalk, and apply eight or ten coats of this mixture, letting each coat dry be fore the next is applied. Then lay on a thick coat of the same size mixed with Armenian bole or yellow oxide of lead, and to this apply the gold leaf in strips with a brush, and rub down with a cotton ball. Burnish as soon as the size sets, and before the work is fully dry, by means of a smooth piece of agate or ivory. This method of gilding is suitable only to indoor work, as dampness will cause the gold to peel. Clean by brushing with hot alcohol or oil of turpentine.