Home › Metallurgy › Another (Melt together oz of zinc oz)

Another (Melt together oz of zinc oz)

Melt together 1 oz. of zinc, 1 oz. of bismuth, and 1 oz. of lead. This alloy will be found to be remarkably fusible (although each of the metals, separately, requires considerable heat to melt it), and will melt even in hot water; it will likewise remain in a fused state on a sheet of paper, over the flame of a lamp or candle. Both of these alloys expand on cooling, and are well adapted for taking casts of medals, etc.

Wood's (patent) Fusible Metal Melts between 150° and 160° Fahr. It consists of 3 parts cadmium, 4 tin, 8 lead, and 15 bismuth.

It has a brilliant metallic lustre, and does not tarnish readily.

Casts from Fusible Metal.

A combination of 3 parts of lead, with 2 of tin and 5 of bismuth, forms an alloy which melts at | weights are then to be placed on the glass, and in the temperature of 197° Fahr.

In making casts with this and similar alloys it is important to use the metal at a temperature as low as possible; as, if but a few degrees elevated, the water which adheres to the things from which casts are to be taken forms vapor, and produces bubbles. The fused metal must be allowed to cool in a teacup until just ready to set at the edges, and then pour it into the moulds, procuring in this way beautiful casts from moulds of wood, or of other similar substances. When taking impressions from gems, seals, etc. the fused alloy should be placed on paper or paste-board, and stirred about till it becomes pasty, from cooling, at which moment the gem, die, or seal should be suddenly stamped on it, and a very sharp impression will then be obtained. Metallic Injection.

Melt together equal parts of bismuth, lead, and tin, with a sufficient quantity of quicksilver.

This composition, with the addition of a small proportion of mercury, is used for injecting the vessels of many anatomical preparations; also for taking correct casts of various cavities of the body, as those of the ear. The animal structure may be corroded and separated by means of a solution of potassa in water, and the metallic cast will be preserved in an isolated state.

For Cushions of Electrical Machines.

Melt together in a crucible 2 drs. of zinc and 1 of tin; when fused, pour them into a cold crucible, containing 5 drs. of mercury. The mercury will combine with those metals and form an alloy (or amalgam, as it is called) fit to be rubbed on the cushions which press the plate or cylinder of an electrical machine. Before the amalgam is applied it is proper to rub the cushion with a mixture of tallow and beeswax.

For Varnishing Figures.

Fuse oz. of tin with the same quantity of bismuth in a crucible; when melted add oz. of mercury. When perfectly combined take the mixture from the fire and cool it. This substance, mixed with the white of an egg, forms a very beautiful varnish for plaster figures, etc.

Moirée Metallique. - A Method of Ornamenting the Surface of Tin Plate by Acids.

The plates are washed by an alkaline solution, then in water, heated, and sponged or sprinkled with the acid solution. The appearance varies with the degree of heat and the nature and strength of the acids employed. The plates, after the application of the acids, are plunged into water slightly acidulated, dried, and covered with white or colored varnishes. The following are some of the acid mixtures used: Nitro-muriatic acid, in different degrees of dilution; sulphuric acid, with 5 parts of water; 1 part of sulphuric acid, 2 of muriatic acid, and 8 of water; a strong solution of citric acid; 1 part nitric acid, 2 sulphuric, and 18 of water. Solution of potash is also used.

To Plate Looking-glasses.

This art is erroneously termed silvering, for, as will be presently seen, there is not a particle of silver present in the whole composition. a little time the quicksilvered tin-foil adheres so firmly to the glass that the weights may be re moved without any danger of its falling off. The glass thus coated is a common looking-glass.

About 2 oz. of mercury are sufficient for covering 3 square feet of glass.

The success of this operation depends much on the clearness of the glass; and the least dirt or dust on its surface will prevent the adhesion of the amalgam or alloy.

Liquid Foil for Silvering Glass Globes.

Melt together 1 oz. of clean lead, and 1 oz. of fine tin, in a clean iron ladle; then immediately add 1 oz. of bismuth. Skim off the dross, remove the ladle from the fire, and before it sets add 10 oz. of quicksilver. Now stir the whole carefully together, taking care not to breathe over it, as the fumes of the mercury are very pernicious. Pour this through an earthen pipe into the glass globe, which turn repeatedly round.

Another. To 4 oz. of quicksilver add as much tin-foil as will become barely fluid when mixed.

Let the globe be clean and warm, and inject the quicksilver by means of a pipe at the aperture, turning it about till it is silvered all over. the remainder run out, and hang the globe up.

Let Another. For this purpose 1 part of mercury and 4 of tin have been used; but if 2 parts of mercury, 1 of tin, 1 of lead, and 1 of bismuth are melted together, the compound which they form will answer the purpose better. Either of them must be made in an iron ladle, over a clear fire, and must be frequently stirred.

Martin's Process for Silvering Glass.

Prepare, 1. A solution of 10 grammes of nitrato of silver in 100 grammes of distilled water. 2.

Take solution of ammonia of 13° Cartier's areometer. 3. A solution of 20 grammes of pure caustic soda in 500 grammes of distilled water. 4. A solution of 25 grammes of ordinary white sugar in 200 grammes of distilled water. Pour into this 1 cubic centimetre of nitric acid, of 36°, and boil for 20 minutes; then make up the volume of 500 cubic centimetres with distilled water and 50 cubic centimetres of alcohol at 36°. This done, prepare an argentiferous solution, by mixing in a flask 12 cubic centimetres of solution 1, then 8 cubic centimetres of solution 2, then 20 centimetres of solution 3; and, lastly, make up a volume of 100 centimetres by 60 centimetres of distilled water.

If the directions have been properly observed the liquid will remain limpid, and a drop of solution of nitrate of silver will produce a permanent precipitate. After being left quiet for 24 hours the solution is ready for use. Clean the surface to be silvered with a cotton plug moistened with a few drops of nitric acid; then wash with distilled water, drain, and place it on supports on the surface of a bath composed of the argentiferous liquid, to which has been added 1-10th or 1-12th of the solution of sugar (4). Under the influence of diffused light the liquid becomes yellow, then brown, and, after from 2 to 5 minutes, the whole surface of the glass will have been silvered. After 10 or 15 minutes it will have attained the required thickness. Wash first with ordinary water, then with distilled water; drain, dry, and polish with rouge on chamois. (A table of French Weights and Measures will be found at the end of the

On tin-foil, fitly disposed on a flat table, mercury is to be poured, and gently rubbed with a hare's-foot: it soon unites itself with the tin, which then becomes very splendid, or, as the workmen say, is quickened. A plate of glass is then cautiously to be slid upon the tin-leaf, in such a manner as to sweep off the redundant mereury which is not incorporated with the tin; leaden | trace of grease or dust; then with the point of a volume.) Mode of Repairing the Silvering of Looking-glasses.

Uncover and clean the damaged spot by very careful rubbing with fine cotton until there is no