Dissolving silver solder.—Nitric acid one part; water four parts.
Dissolving sealing-wax.—Place for a time in a solution of spirits of wine.
Resist Varnish.
Dissolve resin, or copal, in essence of turpentine, or boiled linseed oil; to give it different shades of colour, add red lead, chrome yellow, or Prussian blue.
Plate Powder.
Whitening, two parts, white oxide of tin, one part, calcined hartshorn, one part. Reduce to a powder and well mix together; apply as usual.
Electro-plating Soft Solder.
Take nitric acid, 1 oz.; water, 2 oz.; copper about 1 oz. in small flat pieces; when the copper has all dissolved and effervescence has ceased, the solution is ready for use. To apply it, take up a few drops by means of a camel-hair pencil and apply it to the desired part, then touch it with a bright piece of steel, and there will be instantaneously a film of copper deposited. If the copper has not spread all over the desired part, the process should be repeated, when deposition in the plating bath will take place with perfect success.
Another Recipe.
Take sulphate of copper (that which accumulates in the whitening mixture), one ounce; water, six ounces. Reduce the sulphate of copper to a fine powder and dissolve it in the water. Treat according to the directions given in the previous one. A good mixture for effecting the same result may be made by dissolving verdigris in vinegar.