This page has been robot translated, sorry for typos if any. Original content here.

Gypsum products, such as antique bronze, ivory, wood, etc.

Gypsum products are given the appearance of antique bronze , with lone bone, 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 °C , it is brought to 45 ° C and only at the end - to 55 ° C. It is not recommended to raise the drying temperature higher and speed up the process. You can and simply stand the product in a dry warm place for several days. Then it twice necessarily impregnated with hot linseed oil or a solution of shellac and rosin in technical alcohol. The oil or varnish is applied with a wide flute brush. Such a primer makes the gypsum non-hygroscopic, and there are no stains on the tinted surface. After priming, the product is again dried. Impregnated with linseed gypsum with the passage of time acquires a view close to the old marble. A piece of plaster, covered with shellac varnish, resemble terracotta.

Just as simple and toning for wax. For this, the surface of the plaster product is covered with a solution of wax with turpentine or gasoline and a small amount of yellow oil paint. After 2 hours the product is wiped with a soft rag to a shine.

When making a product "under the bone", it is first treated with "soap". 30 grams of planed white soap is dissolved in a liter of hot boiled milk, cooled and bristled with a brush applied to the surface. After drying, polish the product with nitro-lacquer, slightly tinting the grooves with a yellow oil paint. To the surface does not shine, it is wiped with talcum powder.

When patching plaster products (painting "under bronze"), use oil paints, having previously selected them by color. For example, for the brown tone, the following composition is recommended (in parts by mass): ocher - 11, natural sienna - 33, soot - 28, turpentine - 70, desiccant - 70. For greenish-brown tone: ocher - 120, natural sienna - 196 , soot - 9, greens - 6, turpentine - 200, desiccant - 200.

The paint is applied in 3 layers. The convex parts of the product are covered with a liquid composition, the grooves are thick. The first coat of paint should be light. After drying it is slightly processed with a fine sandpaper and wiped with acetone. The second layer should be more dark and dense, for which a small amount of bronze powder is introduced into the composition. After the second layer has dried, a third is applied. It is diluted with turpentine, in which beeswax is dissolved ( 40 grams on 500g solvent). Wax makes the paint dull. Before the final drying of the third layer, it is slightly removed on the projecting parts of the relief. Then rub the tinted surfaces with a soft flannel, powdered with talc, and in places that it is desirable to shade, - a mixture of talcum powder with chromium oxide powder. To enhance the effect of toning, the convex parts can be powdered with a mixture of graphite powder and bronze powder.

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

Toning gypsum products "under the old bronze" is almost identical to obtaining a patina on real bronze:

1.   First, the gypsum article is impregnated with linseed oil and left overnight. Then cover it with a mixture of bronze powder diluted in a varnish, dry for 20 minutes and apply a second layer of the mixture. When it dries, the surface of the product is covered with the following composition: 10 grams silver nitrate dissolved in 100 g acetic acid and dilute 300 g water; to get this or that tone, you can enter the appropriate pigments. A thin layer of bronze powder applied to the product is oxidized by this solution. The more concentrated the solution, the more oxidized the film. The processed product is either wiped with a velvet rag or covered with wax dissolved in turpentine.

2.   To give gypsum figures an antique bronze, two solutions are prepared: 1) Flaxseed oil is boiled with a solution of caustic soda for soap, add the solution of common salt and boil until the separation of grains of soap; the solution is filtered through a linen cloth, squeezed out soap, dissolved in distilled boiling water and filtered. 2) 4 copper vitriol and 1 iron vitriol are dissolved together in distilled water, they are planted, part of the solution is boiled in a clean copper vessel and the first solution is poured into a precipitate. Separating the green tart sediment, the remaining solution is poured into it and boiled again; after a while, the liquid is drained, the precipitate is washed (copper soap) first with hot, then with cold water, finally squeezing it between linen rags to dryness. Then 1 500 flax oil is boiled in 375 minute glazes, filtered through a linen rag and put in a warm place; 468 oils are alloyed with 250 copper soaps obtained above and 156 white waxes in faience ware, with moderate heating (preferably in a water bath). This mixture is applied by brush on a gypsum object heated up to 70 ° ; when the lacquer is no longer absorbed due to cooling, the object is heated again and again covered with varnish until the object is saturated with it. In conclusion, put it for an instant in the heated chamber, then expose it to air until the smell of varnish disappears, rub it with cotton wool or a soft linen rag, and a small amount of bronze or gold powder is applied to some places.

To simulate a cast iron cast, the gypsum product can be coated with a dark gray paint composed of ocher, white and soot on drying oil mixed with siccativa. After the paint has dried, the product is wiped with a dry mixture of graphite, mummy, ocher, white, ultramarine.

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