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Giving to plaster products of a type of antique bronze, an ivory, wood, etc.

Giving to plaster products of a type of antique bronze , from a ivory, wood, etc.

If desired, the surface of the gypsum product can be given the appearance of wood, bronze, cast iron, etc.

Before toning the product is well dried. Drying starts from 25 0С , brings it to 45 0 С and only at the end - to 55 0 С. It is not recommended to raise the drying temperature higher and speed up the process. You can just stand the product in a dry warm place for several days. Then it must be soaked twice with hot drying oil or a solution of shellac and rosin in technical alcohol. Drying oil or lacquer is applied with a wide flute brush. Such a primer makes gypsum non-hygroscopic, and stains are not formed on the tinted surface. After priming, the product is dried again. In the course of time impregnated with drying oil, the gypsum acquires a form close to the old marble. And objects from gypsum, covered with shellac varnish, resemble terracotta.

Toning under wax is just as easy. To this end, the surface of the gypsum product is covered with a solution of wax with turpentine or gasoline and a small amount of yellow oil paint. After 2 hours, wipe the product with a soft cloth to shine.

Finishing the product "under the bone", it is first treated with "soap maker". 30 g planed white soap is dissolved in a liter of hot boiled milk, cooled and applied with a bristle brush to the surface. After drying, the product is polished with nitro lacquer, tinting lightly with a yellow oil paint. So that the surface does not shine, it is rubbed with talcum powder.

When patinating a gypsum product (paint “bronze-colored”), oil paints are used, after selecting them by color. For example, for brown tones, the following composition is recommended (in parts by weight): ocher - 11, natural sienna - 33, soot - 28, turpentine - 70, desiccant - 70. For greenish-brown tones: ocher - 120, natural sienna - 196 , soot - 9, greens - 6, turpentine - 200, desiccant - 200.

Paint is applied in 3 layers. The convex parts of the product are covered with a liquid composition, the depressions are thick. The first coat of paint should be light. After drying, it is lightly treated with fine sandpaper and rubbed with acetone. The second layer should be darker and thicker, for which a small amount of bronze powder is introduced into the composition. After drying of the second layer put the third. It is diluted with turpentine, in which beeswax is dissolved ( 40 g on 500 g solvent). Wax makes the paint matte. Before the final drying of the third layer, it is slightly removed on the protruding parts of the relief. Then, tinted surfaces are rubbed with a soft flannel, powdered with talcum powder, and in places that it is desirable to shade, with a mixture of talc and chromium oxide powder. To enhance the effect of tinting, the convex parts can be powdered with a mixture of graphite powder and bronze powder.

To imitate dark bronze, it is recommended to use ocher light or gold, natural sienna, natural umber, soot; for light bronze - natural umber, natural carbon black or sienna, light ocher or golden ocher, chromium oxide or green cobalt, lead or zinc white.

Tinting plaster products "under the old bronze" is almost identical to getting patina on real bronze:

one.   First, the gypsum product is impregnated with linseed oil and left overnight. Then it is coated with a mixture of bronze powder diluted in varnish, dried for 20 minutes, and a second layer of the mixture is applied. When it dries, the surface of the product is coated with the following composition: 10 g silver nitrate dissolved in 100 g acetic acid and diluted 300 g water; To obtain a particular tone, you can enter the appropriate pigments. A thin layer of bronze powder deposited on the product is oxidized with this solution. The more concentrated the solution, the more oxidized the film. The processed product is either wiped with a velvet cloth or coated with wax dissolved in turpentine.

2   To impart the appearance of antique bronze to gypsum figures, two solutions are prepared: 1) Linseed oil is boiled with a solution of caustic soda on soap, salt solution is added and boiled until the grains of soap are extracted; filter the solution through a linen cloth, squeeze the soap, dissolve it in distilled boiling water and filter. 2) 4 copper sulphate and 1 iron sulphate are dissolved together in distilled water, filtered, part of the solution is boiled in a clean copper vessel and the first solution is poured in until a precipitate forms. Separating the green ragged sediment, the rest of the solution is poured into it and again boiled; after some time, the liquid is drained, washed sediment (copper soap), first with hot, then with cold water, finally squeeze it between linen cloths dry. Then boil 1,500 pure flaxseed oil in 375 smallest slabs, filter through a linen cloth and put in a warm place; when settled, 468 oils are fused with 250 copper soaps obtained above and 156 white wax in faience ware with moderate heating (preferably in a water bath). This mixture is applied by brush to a plaster heated to 70 ° ; when, due to cooling, the varnish is no longer absorbed, the object is heated again and varnished again until the object is saturated with it. In conclusion, they put it for one instant into the heated chamber, then they are exposed to air until the smell of varnish disappears, rubbed with cotton wool or a soft linen cloth, and a small amount of bronze or gold powder is applied to some places.

To imitate iron casting, the gypsum product can be coated with a dark gray paint made up of ocher, white and soot on linseed, mixed with a siccative. After drying, the product is rubbed with a dry mixture of graphite, mummy, ocher, white, and ultramarine.

To make the surface of the product of gypsum shiny, it is coated with a composition of 5 parts of glycerin and 95 parts of silicate glue.