To obtain Tucker bronze, grease polished iron and expose it for from two to five minutes to the action of vapors arising from a bath of equal parts of concentrated hydro-chlorate and nitric acid. Next coat the iron with vaseline and heat until the decomposition of the latter (or vaseline) commences.
To bronze small brass articles, clean same well to get rid of grease, etc., and apply, with a brush, a mixture consisting of:
3 parts Oxide of Iron, 3 parts White Arsenic, 36 parts Hydro-chloric Acid.
The process is finished by oiling well, after which the article may be lacquered or varnished.
To bronze cast-iron the first step is to clean the surface and then coat it uniformly with a layer of olive oil (a low grade will answer), then heat it without, however, raising the temperature to the burning point of the oil. This will cause the cast-iron, at the minute the decomposition of the oil is accomplished, to absorb oxygen and will cause the formation of a brown surface of oxide, whose adherence is very firm. It will acquire a good polish, thus giving the surface of the cast-iron a bronze-like appearance.
To bronze copper and brass neutralize 20 parts of ammonia with vinegar and compound the solution with 6 parts sal-ammoniac and 10 parts verdigris. First rid your object of grease, then brush with the solution, the operation being repeated until the shade of color wanted is produced. After this has been secured pour off the solution and recleanse by hot water. Repeat the rinsing twice. The best drier for articles is sawdust.
A fine antique green bronze is obtained by repeated alternate applications to brass or copper of diluted acetic acid and exposure to the fumes of ammonia. A more rapid method for giving this appearance is found in the immersion of the articles in a solution of 1 part of per-chloride of iron in 2 parts of water. The longer the immersion the darker the shade. A second method consists in boiling the articles in a strong solution of nitrate of copper. A third method is the immersion of 2 ounces of hypo-sulphate of sodium and 2 ounces of nitrate of iron in 1 pint of water.
To secure a bronze-like surface on iron and steel, and one impervious to oxidation, first clean the object, then expose for two or three minutes to the action of the fumes of a heated mixture of nitric and hydro-chlorate acid in equal proportions at a temperature ranging from 550 degrees to 660 degrees Fahrenheit. When the object has cooled rub it with vaseline and then heat until decomposition of the vaseline commences. Repeat the vaseline treatment. Should a coloring lighter than bronze be desired, mix acetic acid with the other acids. In making this bronze one should be very careful both in handling and preserving these acids.