Brass is an alloy of copper and zinc, while bronze is a composition of copper and tin. It has a bright yellowish appearance, and is susceptible of a high polish. It tarnishes very easily and is consequently generally protected by a coat of shellac, which, however, will not entirely prevent it from changing in color. The use of brass for hardware is confined principally to door-knobs, small hinges and bolts, which are usually finished in the natural color of the metal.
To keep brass knobs looking well will require more labor than for bronze.
Bronze. - Bronze is more largely used in the manufacture of finished hardware than any other metal. It can be cast with great ease and in the most delicate patterns, and may be finished in a great variety of styles and colors.
The general method of producing the different colors of bronze hardware is as follows: The casting, after being trimmed or chased as may be necessary, is thoroughly cleaned by immersion in a strong acid bath, followed by one in a weak alkali and clear water. It is then suspended in a bath of hot acids specially prepared with various chemicals to produce certain changes in the color of the metal. When the desired shade is reached the casting is removed, dried in sawdust and rubbed down to an even tone on a buffing wheel. Almost any color or shade can be had with bronze by proper treatment.
The colors thus obtained, however, should not be considered as permanent, as they are merely laid on the surface. Copper, silver, gold and nickel finishes are obtained by plating either bronze metal or over iron and steel that has first been plated with bronze or copper. "Bronze hardware is sure to change in time, no matter how it may be finished, and generally the stronger tones are the least satisfactory in the end, fading out to unpleasant musty hues." For plain, smooth hardware the natural color of the bronze will prove the most satisfactory in the end, as it can always be kept bright by polishing.
The various finishes given to solid, or bronze-plated hardware, differ more or less in color and appearance with different manufacturers, and the manner of designating them also differs. They also vary in cost, the relative cost being somewhat in the following order, plain bronze being usually the cheapest and taken as the standard, and a fixed charge being added for the other finishes, according to the size of the article. The brackets indicate the same price.
Light bronze. Brass, natural.
Old brass, shaded. Copper, oxidized, streaked.
Copper, red antique.
Old brass, plain.
Dead black, electroplate.
Silver, light or mottled.
Gold, yellow, red or green tints.
Both bronze metal and bronze-plated iron goods are made plain and figured. In the cheaper grades of goods the figured or ornamented hardware, particularly door-knobs, is usually a little cheaper than the plain surfaces, and the author's experience has been that in a cheap grade the figured knobs show wear less than the plain knobs. In the better grades of hardware ornamentation adds to the price, although if the ornamentation is artistically designed, not in proportion to the improved appearance.