Metal Coloring and Finishing, Vol. 1 (Classic Reprint)

Excerpt from Metal Coloring and Finishing, Vol. 1

The subject of metal finishing and coloring has received but scant attention in mechanical publications; this is rather surprising when we note the inclination of the manufacturers of today to combine this artistic treatment with utility, and add contrast of color to the severe straight-line plainness of our commercial products, to produce more beautiful effects. There is nothing new in metal coloring. Ages ago it was old in Japan, and to the Orient we must really turn for original authority on successful coloring of metals.

The purpose of this book is to give to those who are interested the results of the experience of a number of authorities in coloring metals, solely from the manufacturing side, rather than from the chemists standpoint. So many conditions enter into the work that no law can be laid down by which everyone can obtain the same satisfactory results, for with everyone the coloring of metals must at first be more or less of an experimental nature. A cheap monochrome color can be produced by the novice who is unacquainted with the metallurgical properties of metals and chemical actions of solutions used, but the very fact that the slightest change in the alloy, as well as in the strength of the coloring solutions, produces a different shade of coloring under the same treatment, makes it essential that the operator should have considerable knowledge of metallurgy and chemistry for any except the simplest work.

First, let us consider the different methods and conditions under which color can be obtained, viz., by heat-treatment alone; by varnishes and lacquers; and by corroding agents or chemical compounds. We will treat each under its separate heading, but first will refer briefly to the Bunsen burner, by the use of which, together with a pot of heavy fish or lard oil and a pair of tweezers, one can color small pieces by the heat process.

The Bunsen Burner

We will tak…