Recent Foreign Inventions. Coating and Ornamenting Zinc.

Scientific American 47, 7.8.1852

The following are the leading features of a patent recently granted in England to Francis H. Greenstreet, and which is selected by us from the London Mechanics' Magazine:-

These improvements consist in coating and ornamenting zinc or zinced surfaces by means of acids, alone or combined with other matters capable of acting chemically on the surfaces. The solution used may be applied by sprinkling, dapping, spreading, or marbling; and the surfaces coated are capable of further ornamentation by painting, which may be done with common oil colors. Among the preparations which the patentee recommends for coating and ornamenting zinc or zinced surfaces, are the following: -

1. Muriatic acid diluted with water to a strenght of 1*114. The coating produced by this solution is of a light ash color.

2. Chrome yellow, ground fine with soft water, and mixed with preparation 1 to a liquid consistence. This gives a yellowish grey color.

3. The pigment known as "mountain or Saxony green," mixed gradually with preparation 1 to a thing paste, and stirred till effervescence ceases. This produces an iron grey color tinged with green.

4. White lead, ground fine with soft water, and mixed with preparation 1, produces a grey coating. Where expense is not an object, Kremnitz white may be used instead of the white lead.

5. Flour of sulphur ground fine with water and mixed with preparation 1. This mixture gives a yellowish white coating.

6. Butter of antimony may be mixed with the before-mentioned preparations. When used alone it produces a black color, but when mixed, does not affect the color of the preparation with which it is used. It produces a good ground for subsequent painting or other application.

7. Butter of antimony diluted with distilled water. This produces a fne coating, resembling in color India ink.

8. Butter of antimony mixed with spirits of turpentine. This preparation, when applied alone, produces a black color; it may have pigments of different kinds mixed with it, and the effect will then vary according to the nature of the color employed.

The surfaces adter having been coated by the means above mentioned, and further ornamented, if thought desirable, should be protected by a coating of varnish. Copal varnish may be used for this purpose; but the patentee recommends the used of wax, or mixtured sontaining wax, as this substance is an effectual preservative against oxidation, and easily renewed or kept in good condition.

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