To produce the rich brown finish that is commonly used on large guns use sulphate of copper, 1 ounce; sweet spirits nitre, 1 ounce; distilled water, 1 pint.
Four coats are applied, allow several hours to elapse between the successive coats, brushing after each if necessary. After the last coat rub down hard and allow to dry 24 hours. This gives a reddish-brown color without gloss. By adding arsenic to the mixture before last coat a deeper hue is obtained. The polish is obtained by means of a mixture of boiled oil, beeswax, and turpentine, comparatively thick. Rub in well with cotton cloth and finally with the palm of the hand.
R. P. Perry.
To blue steel without heating it. connect a small steam pipe to a wooden box so that steam may flow continuously into it. Put a bath of the following ingredients in the box: Iron chloride (muriatic tincture of steel), 1 ounce; alcohol (spirits of wine), 1 ounce; corrosive sublimate (mercury bichloride), ¼ ounce; aquafortis (strong nitric acid), ¼ ounce; blue stone (copper sulphate), 1/8 ounce; and water, 1 quart. The vapor arising from this mixture forms a deposit on the articles. After having been exposed to the vapors for a number of hours, they are rubbed off with cloth, and the operation repeated if a darker hue is required. W. J. Kaup.
Mix one part clean sand with one part powdered charcoal, heat the whole evenly in a pan or convenient receptacle until the piece, which has first received its finishing polish and been covered by the mixture, comes to the desired color. When cool, wipe dry with cloth. Neralcm.
A steel-blue enamel suitable for applying to steel and also other metals to give them a steel-blue polished surface, may be made in the following way: Dissolve 1 part of borax in 4 parts of water. Macerate 5 parts bleached shellac in 5 parts of alcohol. In a small quantity of alcohol dissolve some methylene blue of sufficient amount to give the color desired. Heat the first or watery solution to boiling, and while constantly stirring add the alcoholic solution.
Stir until all the lumps are dissolved, and then add the blue solution. Before applying, the surface to be blued should be cleaned and brightened with emery cloth. The enamel is best applied with a soft brush. The solution may be put into a bottle and set aside for future use, provided the bottle is securely corked.
Olney, Ill. T. E. O'Donnell.
To blue gun barrels and other pieces dissolve 2 parts of crystallized chloride of iron; 2 parts solid chloride of antimony; 1 part gallic acid in 4 or 5 parts of water; apply with a small sponge, and let dry in the air. Repeat this two or three times, then wash with water, and dry. Rub with boiled linseed oil to deepen the shade. Repeat this until satisfied with the result.
New Britain, Conn. P. L. Engel.