US2296840A - Finishing process - Google Patents

Description

Patented Sept. 29, 1942 UNITED STATE FINISHING PROCESS Alexander J.-Faust, Grosse Pointe, Mich.

No Drawing. Application March 14, 1938, Serial No. 195,851

11 Claims.

This invention relates to finishing or surfacing processes, and more especially to improved means for applying a metallic high lustre coating, presenting the appearance of a plated surface,

yet applicable, without the use of electricity, by.

a relatively simple procedure involving the steps of painting and bufllng with particular substances, used in a particular sequence. An important aim of the invention is to produce such a metallic high-lustre coating, of mirror-like quality, with the use of no other apparatus than a paint brush or paint sprayingequipment, and bufiing means such as a soft cloth or fur pad.

Previously known non-electric processes for producing such a metallic finish have employed various powdered metals, blown or dusted onto a surface, such as wet varnish, enamel or lacquer, to provide a coating of metal powder cemented to the surface by the paint-like under coating. Even if buffing is resorted to after such an application of metal powder over a wet paintlike coating, it has not been possible, however, to secure a brilliant lustre, truly resembling a continuous metallic surface, and although the dull metallic finishes secured by such previously known processes provide an attractive surface, suitable for many uses, they are in no sense a substitute for platings of nickel, chrome or the like, such as are commonly employed when a bright metallic finish is required. The present process aims to provide a finishing surface coating constituting a substitute for deposited metal plating, and presenting the true appearance of a continuous, polished or naturally brilliant metallic surface, strongly resembling chromium, yet the creation of which is no more difficult or expensive than conventional painting or varnishing processes.

A further object is the provision of such a finishing process which is applicable to non-conducting surfaces.

Other objects will become apparent during the course of the subsequent description.

In carrying out my improved process, the surface to be finished is first given a preparatory or undercoating of paint, varnish, enamel or lacquer, which maybe applied by brushing, spraying or dipping, and is thereafter allowed to dry. Best results have been secured with enamels and lacquers which dry bright without rubbing. I prefer colorless lacquer, although this is not essential. It should have a brilliant gloss when dry, and is allowed to drybefore proceeding.

Whenever hereafter, throughout the specificaelectrotion and claims, the words paint or paintlike are used, they are to be understood as including any initially liquid coating material of the general class above indicated.

The next step is to spread over the undercoating a finely flaked metal, and to cause the flaked particles to leaf together or form a film I having a highly polished surface, which appears to be continuous and uniform. This may be done in several relatively simple ways. In fact, in perfecting my process I had relatively little difficulty in securing a mirror-like finish with the use of powdered or flaked metal, but great difficulty in developing a simple and practical method of preserving the high lustre against deterioration, since not "only the atmosphere, but most finishes which might be placed thereover, 'destroy its mirror-like quality and seem to attack the metal.

My preferred method of securing the metallic coating is to apply by rubbing directly over the undercoating a substance of the character described in Patent No..2,002,891, issued May 28, 1935, to Harriet 1. Hall, as executrix of Everett J. Hall, or some such variation of that product as is sold in the trade, and known as aluminum paste. This contains varying quantities, usually something over half, flaked aluminum, small quantities (about 1% each) of stearic acid and aluminum stearate, and a vehicle in the nature of a petroleum oil or grease;

such as that known in the trade as Varnolene. The aluminum paste is rubbed over the surface and polished to high brilliance with a soft cloth or other suitable bumng means, which causes the flakes to assume a flat position parallel to the surface, and apparently to flow together at their margins, imparting a continuous and highly polished appearance. All excess is rubbed off, and it will be found that the thin, highly polished film adheres to the undercoating with great tenacity, for a reason which I have not been able to determine accurately, although it may be that the petroleum content of the aluminum paste slightly attacks the surface of the undercoating, rendering it slightly adherent without actually destroying its smoothness.

An alternative method of forming the metallic coating is merely to rub the surface of the undercoating with a suitable grease, such as Vaseline, or other fluid substance capable of very mildly attacking the undercoating without destroying its smooth brilliance, rubbing 'such fluid into the finish and rubbing off all excess, and

' then applying the metallic flaked powder, such as aluminum or bronze, by dusting it over the surface. Thereafter the powder must -be rubbed and polished in the same manner, by means of a sheeps wool or soft cloth polisher. It will be found that after a certain point in the rubbing, virtually none of the powder can be rubbed off, yet a very fine finish remains upon the enamel or other surface coating, as before.

When the metallic film has attained the desired brilliance, a protecting coating of water-soluble gelatine is applied thereover, by spraying, brushing or in any desired manner. This may be very thin, but should dry hard and cover the entire finished surface in air-tight form. It is allowed to dry, and over the gelatine coating a more durable, water-resistant, transparent protecting film, such as colorless lacquer or varnish is applied, and this also may be put on either by brushing, spraying or dipping, If absolutely clear or water-white gelatine and lacquer are used, the finish remains extremely brilliant, and in fact when aluminum is used it is difficult to distinguish it from chrome plate.

The application-of the indicated substances in the order named has peculiar virtues. The gelatine adheres very tenaciously to the metallic film, yet is inert and does not attack either the metal or the undercoating, allowing the aluminum flakes to retain their positions and polished condition. The lacquer or varnish on the other hand would attack the metallic film or allow' the flakes to turn to such positions as to destroy the polished appearance, "if applied directly thereto, and would quickly destroy the brilliance. Ordinary synthetic lacquers may be used for the top coating, and these adhere strongly to gelatine yet do not attack it, so that a lastingly bright finish is obtained.

The undercoating or surface need not be colorless, and in fact a pleasing depth of tone is secured with a black under surface. It will be appreciated also that the undercoating or surface might be of any suitable material to which the finely comminuted metal particles might be made to adhere, in the described or any suitable manner.

Without any gelatine or other coating over the metallic film, the brilliance will last for a short while, and such finish may be useful for some purposes, where permanence is not required. If the gelatine is omitted and the lacquer is placed directly over the metallic film, a good protective finish is obtained, althoughthe bright lustre is not secured.

If the gelatine is dissolved in hot water and a small percentage (about 2%) of furfurol added. the gelatine is not only rendered resistant to bacteria, but may apparently be kept indefinitely in a sealed container, and remelted, when it is desired to use the same, by simply heatingjit.

What I claim is:

l. The surface coating process which comprises applying to a relatively hard paint-like surface to be coated a softening agent which attacks the surface only very slightly, thoroughly rubbing over and into such surface finely comminuted metal and buffing and orienting the same to provide a high lustre surface parallel to said first mentioned surface.

2. The surface coating process which comprises applying to a relatively hard paint-like surface to be coated a softening agent which attacks the surface only very slightly, simultaneously rubbing over and into such surface finely comminuted metal and buffing and orientirg said oriented by such rubbing operation to lie substantially in one plane.

5. A process of applying an adherent metallic coating to a relatively hard paint-like surface, which comprises spreading finely comminuted metal over the surface and causing the comminuted particles to adhere to said surface, buffing the surface of the adhering particles to form a metallic film having a desired lustre, and covering said film with a gelatine coating.

6. A process for applying an adherent metallic coating to a relatively hard paint-like surface,

which comprises spreading finely comminuted metal over such surface and causing the comminuted particles to adhere in a coating to said surface, removing the excess, non-adherent particles, coating the adhering particles with a film of transparent material which is inert and unable to attack either saidsurface or the particles, and

coating said film with another film of transparent material which does not deleteriously affect the first mentioned film.

'7. The process of applying a lustrous metallic coating to a desired surface which comprises coating such surface with a smooth paint-like film and allowing such film to dry, applying to such film a fluid agent capable of causing metal particles to adhere to the surface thereof without breaking down its smooth character, applying to such film, while said agent or the effect thereof is still present, a finely comminuted metal, rubbing the comminuted particles to form a sub stantially continuous layer having a desired lustre and removing the excess thereof.

8. The surface coating process which comprises applying to a relatively hard paint-like undercoating a mildly acting softening agent, rubbing such agent thoroughly into and from the surface to soften the same at the top only to an extent which is imperceptible to the naked eye, and then applying and rubbing onto the surface finely comminuted aluminum to cause the same to adhere thereto and to provide a buffed surface continuous in appearance and substantially parallel another initially liquid layer of translucent protective gelatinous material, the paint-like layer being insoluble in the liquid constituent of said last mentioned protective material, and the metallic coating being sealed between said layers.

10. The process of forming a composite film having a.

gh metallic lustre, which comprises laying down an initially liquidpaint-like base layer; allowing the same to harde the hardened layer being insoluble in water, then spreading over said hardened layer a plurality 'oiflne metallic particles, bufiing the particles to orient; and polish the same to provide a metallic coatin which appears to the eye as a smooth and substantially continuous surface parallel to the plane of said layer, causing said particles to cling to the surface only of said hardened layer, covering said metallic coating with a second initially liquid layer of adherent translucent protective gelatinous material carried inowater as a vehicle, and

allowing said second layer to harden, whereby the vehicle of the second mentioned layer, it it penetrates between. the metallic particles, is in-, capable of softening the base layer and so disturbing the orientation or the particles.

11. Theprocess of iorming acomposite fllm' having a high metallic lustre, which comprises laying down an initially liquid paint-like base layer which is insoluble in water when dry, al-

lowing said material to harden, spreading over and causing to adhere to saidbase layer a plurality of fine particles of metal, bufiing-said particles to orient and polish the same until they form a metallic-coating presenting a smooth and substantially continuous surface, causing said particles to cling to thesurface only of said hardened layer, applying to said metallic coating a layer formed of another initially liquid adherent transparent protective material carried in water as a vehicle and which is insoluble in an top layer formed of organic solvent, allowing said last mentioned protective layer to harden, and applying thereover a an initially liquid adherent and transparent paint-like material carried in an organic vehicle which is incapable oi attacking the protective layer.

ALEXANDER J. FAUST.