To give iron and steel a bluish color cleanse the article thoroughly with lime and then brush it over with a mixture composed of the following ingredients:
16 parts Hydro-chloric Acid, 8 parts Fuming Nitric Acid, 8 parts Butter of Antimony.
Hydro-chloric acid is to be added drop by drop very slowly, in order to avoid heating. The mixture is to be applied to the steel with a cloth; the steel is then rubbed with green young oak wood until the blue color desired is produced.
The following two formulas for making blue prints are in general use. They both make good prints, but the one marked No. 2 gives the clearer print.
1 oz. of Red Potash,
1 oz. of Citrate Iron of Ammonium,
1 pint of Water.
1 oz. of Red Potash,
1 1/4 oz. of Citrate Iron of Ammonium,
1 1/2 pints of Water.
To give small articles of sheet-steel a blue appearance dip them in a fluid alloy consisting of 25 parts of lead and 1 part of tin, melted at the requisite degree of heat for bluing. This dipping may also be made in a sand bath and maintained at the requisite temperature, of 4.78 degrees Fahrenheit for the pale blue and 5.72 degrees Fahrenheit for dark blue.
Steel is "blued" by heating it evenly in an ash bath - that is, a quantity of sand is spread over a sheet of boiler iron and heated up to about the boiling point of oil, say 600 degrees. If a little oil is rubbed over the surfaces with a piece of waste the color will be better. All articles to be colored should be polished.
To put a durable blue on iron or steel without heat, apply nitric acid and let it eat into the iron a little, then the metal will be covered with a fine film of oxide. Clean, oil and varnish.
To produce the appearance of antique brass, dissolve 1 ounce sal-ammoniac, 3 ounces cream of tartar, and 6 ounces common salt in 1 pint hot water; then add 2 ounces nitrate of copper dissolved in a half pint of water; mix well, and apply it repeatedly to the article by means of a brush.
Bristol brass is composed of either
75 5-10 parts Copper, 24 5-10 parts Zinc, or
67 2-10 parts Copper, 32 8-10 parts Zinc, or
60 8-10 parts Copper, 39 2-10 parts Zinc.
Brasses for side rods are made of:
1 part Tin, 6 parts Copper, and to 100 pounds of this mixture add one-half part each of zinc and lead.
Take very finest flour of emery paper and oil, bringing the surface to a very smooth and even finish first. Rub well with rotten stone and oil on a piece of soft leather and finish with dry whiting and a rag. Then, if desired to lacquer, see that every part is free from oil and very clean. Take shellac varnish, thin with 95 per cent. alcohol, and let it stand a few hours to settle. Afterward apply the lacquer with a camel's hair brush, keeping the surface of the brass work very warm all the time.