US1268987A - Metal coating. - Google Patents

Description

E. W. McMULLEN.

METAL'COATING.

.APPLICATION FILED FEB. 1|, 1918.

1 ,26,97@ Patented J 11110 11, 1918.

AA COOK/P UNITED STATES PATENT OFFICE.

EABLE W. MOMULLEN, 0F KENOSHA, WISCONSIN, ASSIGNOR T0 SIMMONS COMPANY, OF KENOSHA, WISCONSIN, A CORPORATION OF DELAWARE.

METAL COATING.

Specification of Letters Patent.

Patented June 11, 1918.

Application filed February 11, 1918. Serial No. 216,581.

and State of Wisconsin, have invented cer tain new and useful Improvements in Metal Coatings, of which the following is a specification.

My invention relates to improvements in metal coatings and has particular reference to an ornamental finish for steel or other ferrous metal.

The object of the invention is to provide for steel articles a practically indestructible coating, or finish, which shall possess sanitary and ornamental properties and characterlstics to a high degree, while at the same time having great durability and mechanical strength and the maximum adhesive effect.

My invention briefl involves the covering of steel or other errous metal with an electrolytic deposit of zinc and subsequently applying, by sprayin or otherwise, to the top of said coating a 'shing coat of tough lacquer or analogous materia The drawing shows a piece of ferrous metal coated according to my'process.

During recent years liquid finishes, generally known in the trade as lacquers have been developed and utilized to a considerable extent for the purpose of coating metal articles and with considerable success in sofar as they may have been used upon nonferrous or non-oxidizable metals such as brass, copper and the like. However, so far as I am informed, no practical lacquer has, up to the present, been successfully del veloped for use directly upon the outer surface of an article which when in the proper tion, does not furnish a foundation to which lacquer will stick with an degree of certainty. Also it has been ound that when lacquer is applied directly to a steel surface it does not adequately protect the steel against rust due to the oxidizing effect of the atmosphere. I

I have discovered that certain grades of lacquer and particularly that kind of lacquer which has a cellulose or celluloid base can be successfully applied to steel, if the latter be first coated electrically with a non-ferrous metal such as zinc. 'This discovery,

me after numerous attempts to was made by first coating metal secure the same result by 'rying out my invention.

made of a ferrous metal finished condiparts with the zinc by means of the hot process, that is to say by dippin the article into a bath of molten zinc. These attempts of mine to lacquer hot galvanized steel parts were, however, uniformly unsuccessful for the reason, I believe, in the light of my present knowledge, that a hot galvanized coating is too smooth to provide the necessary adhesive effect. On the other hand I have discovered that the surface of a steel article to which there has been applied an electrolytic deposit of zinc furnishes an admirable foundation for the lacquer for the reason that the surface of said deposit when examined under a microscope is found to be of a uniform crystalline texture to which the lacquer adheres with the reatesttenacit Although it is possible that other types of lacquer may be employed in practising my invention, I prefer to use a lacquer of the cellulose group, a. a, a lacquer derived from cellulose. The one with which I have secured the best results is the celluloid lacquer.

No special apparatus is required for car- As successfully carried out the steel article to be coated is galvanized electrically by the cold process in the same manner as any ordinary electroplating process, after which the article is washed and dried in the usual manner and when dry is sprayed with the lacquer by means of a suitable air brush. When dry the lacquer coating is strongly'adherent to the surface of the metal and will not flake off or crack even though the surface of the metal be very seriously disfigured or otherwise distorted out of its original shape. This feature is of inestimable value in the case of metal bedsteads or other furniture constructed of relatively thin steel sheets or tubing such as is now rapidly becoming the best modern practice in metal furniture construction.

My improved 0 advantage that in ating has the additional the event the surface of the lacquer is accidentally removed by abrasion, or otherwise, the surface of the steel does not oxidize and rust because it is protected by the zinc coating beneath the lacquer.

It should be understood that my invention is not confined to transparent lacquer but may be used for producing all kinds of lac- @3 answer quer finish according to present day lacing of zinc upon the said surface and subquering practice. sequently coating the deposit with a cellu- I claim lose lacquer. 15

1. The improvement in the art of coating 3. As a new article of manufacture, a 5 steel or other ferrous metal which consists lacquered ferrous article provided with an in electrolytically depositing a coating of intermediate electrolytic zinc deposit under zinc upon the surface of the metal and subthe lacquer coating. sequently covering the said deposit with 4. Asa new article of manufacture, a steel 20 lacquer. part coated electrolytically with zinc de- 10 2. The improvement in the art of beautiosit, and having an outer coat of cellulose fying and protectinv a steel surface which acquer covering said deposit. conslsts in electrolytically depositing a coat- JEARLE McMULLEN.

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