US881029A - Method of coating metals. - Google Patents

Description

No. 881,029. PATENTED MAR. 3, 1908.

A. SANG.

METHOD OF COATING METALS. APPLICATION nun APB.13. 1901.

ALFRED SANG, OF SEWICKLEY, PENNSYLVANIA.

METHOD OF COATING METALS.

7 Specification of Letters Patent.

Patented March 3, 1908.

Application April 13, 1907. Serial no. 367,916.

To all whom it may concern:

Be it known that I, ALFRED, SANG, of Sewickley, Allegheny county, Pennsylvania, have invented a new and useful Method of Coating Metals, of which the following is a full, clear, and exact description, reference being had to the accompanying ,drawing,

forming part of this specification, in which though other materials may be used, which is then covered and sealed. ,This coating box or rece tacle is connected by a pipe or conduit wit a retort or ot contaimng the dust of the coating meta. In the case of zinc, this dust will referably be the ordinary commerical zinc list which contains some oxid of zinc. If the metal dust does not contain oxid, such oxid should be added to it. I also preferably employ a reducing or fixing agent, such as cyanld of potassium, asphaltum, coal oil, or other reducing agent or agents which may be placed in the retort, in

the coating box, or applied as a coating on the articles in the box. The proportion of the reducing agent may be varied widely Without materially affecting the result. The pot or retort containing the zinc dust is then eated to a point below the melting point,

-but sufiicient to vaporize this zinc dust.

The temperature is preferably fromv two hundred to five hundred degrees centigrade, though this may be- .varied Within certain limits, depending upon the vaporization oint of the particular metal dust employed.

. he coating receptacle is also preferably heated in orderto prevent the deposition of w the coating metal upon its inner surface, and

/ Lgrade.

this temperature imay be varied Widely, "though I prefer to heat the box from about two'hundred to-three hundred degrees centi In the form of apparatus shown in the drawings, 2 is the retort containing the metal containing the metal articles 4, and 5 is the pipe connecting the boxes in which I preferablyrovide a central valve 5. I have shown t e retort as mounted in a setting connected to an external combustion chamber 6, the gases passing from ,the setting through a flue 7 containing the coating receptacle on their Way to the stack flue.

8 and 9 represent the removable covers of the retort and coating box respectively, these preferably having flanges seating in rooves containing asbestos gaskets, or simiar packing material,

When the dust in the retort is heated to the vaporizing point, the vapor from the dust passes into the coating receptacle, reacts coating metal upon the articles. This coating is of atough, strongly adherent character, and under most conditions is of a fine granular nature and bright, or else crystallinein character. It is substantially amalgamated or alloyed with the surface portionof the article itself. A i i The depth or thickness of the coating or deposit may be varied, according to the length of time which the operation is continued, the temperature employed, &c. Pyrometers 10 and 11 are preferably employed for the pot or retort,-and also the coating receptacle,' so that the heat may be kept withm desirable limits.

Instead of supplying the reducing agent in the retort or pot with the metal dust, it may beapplied to the articles in the coating receptacle. 'In such case ilhave found that where asphaltum is used as a reducing agent forming'a coating on the article, the zinc or other metallic deposit will be formed under the asphaltum. This is of especial advantage in. structural steel, since the structural shape will not only be providedwith the protective metallic coating, but this coating in turn covered by the asphaltum, without any further operation. Articles provided with a coveringof paint or non-metallic materials may thus be provided with a metallic coating under'the non-metalliccovering, using the reducing agent ineither receptacle, or as the non-metallic coating itself. I have found that whereeither asphaltum,

dust and reducing agent, 3 the coating box bitumen, heavy oil or similar material is used (ill with the reducing agent and deposits the with the metal dust, a double coating is given, the inner coating being metallic and. the outer one non-metallic.

The advantages of my invention will be apparent to those skilled in the art. The articles do not need to be brought into contact with. the metal dust, and large and heavy articles may be treated cheaply and easily. The coating is of the highly desirable tou h adherent character. The process may )e carried out by placing the articles in the same pot or receptacle with the dust, and without contact therewith; metal dust other than zinc may be employed; and many.

other changes may be made without departing from my invention.

I claim 1. The process of depositing coating metal upon a metallic surface, consisting in vaporizing the dust of the coating metal, and subjecting the metal surface to be coated to the action of said vapor whileout of contact with the dust; substantially as described.

2. The method of'coating metal surfaces, consisting in heating and vaporizing the dust of the coating metal, treating the vapor with a reducing agent, and depositing the vapor upon the surface to be coated while said surface is out of contact with the metal dust; substantially as described.

The method of coating metal surfaces, consisting in vaporizingthe dust of the coating metal in the presence of a reducing agent, heating the surface to be coated, and subjecting it to the action of said vapor while out of contact with the dust; substantially as described.

4. The process of depositing coating metal upon a metallic surface, consisting in vaporizing the dust of the coating metal by applying heat of a temperature below the va oriz ing temperature of the metal itself, an subjecting the metal surface tobe coated to the 6. The process of double coating a metallic surface, consisting in vaporizing the dust of the coatin metal, and subjecting the metal surface to be coated to the action of said vapor while out of contact With the dust and in the presence of the vapor of a non-metallic materlal, which acts as a reducing agent for coating; substantially as described.

In testimony whereof, I have hereunto set my hrnd. ALFRED SANG. Witnesses:

JonN MILLER, H. M. CORWIN.

the metallic vapor and gives an additional

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