Improvements in' Enamelling metal.
Year: 1895

page_text: being date of first Foreign Application (in TYTA NOV., 1034
United States of America),
Date of Application (in: United Kingdom), 19th Apr., 1895
Complete Specification Left, 19th Apr., 1895-Accepted, 22nd.'June.. 1895
Date of Application (in: United Kingdom), 19th Apr., 1895
Complete Specification Left, 19th Apr., 1895-Accepted, 22nd June, 1895
Improvements in' Enamelling metal.
I. JAMES COCHRAN, Manufacturer, of 281 Decatur Street, Brooklyn, in the
County of Kings and State of New York, United States of America do hereby
declare the nature of this invention and in what manner the same, is to be
performed; to be particularly described and ascertained in and by the following
statement :-
My invention relates to enamelling metal, more particularly steel or analogous
metal, to which enamel will not properly adhere, and has for its particular: object
to enamel such metal with one or more coats of enamel. presenting a mottled effect,
but I wish to have it understood that the invention is not limited to enamelling"
steel or to the number or character of the coats.
My invention consists mainly in the process and article of manufacture.herein-
after set forth and claimed, which is, broadly stated, interposing between the
1a metallic
metallic vessel and the enamel (preferably by electro-deposition) of
binder which will act as a bond between the metallic-base and the enamel when
fused.
"
"
My process may be practised in various ways upon various metals and by the
employment of various substances; so therefore I will describe done method of
enamelling" which I practise, leaving it understood, however, that Ido: not limit
myself to any particular metal article or enamelling composition.
One method of practising my process, which I may state by way ofi example,
is as follows: I first take the metal article and submit it to a proper cleaning.
process so as to present a clean surface to operate upon. I then take this article
and immerse it in a suitable bath, which in the present instance will be a bath of a
salt of cobalt, although other analogous metallic, salts may be used, and for this.
I wish thereby to be
reason whenever I use the term cobalt in this and their salts it.
understood as also including other and analogous
...
but the best substance for the purpose is a magnetic metal, such as cobalt. I then
pass a current of electricity through the bath, from the bath to the metal articles
by the employment of a suitable anode. This has the effect of depositing, the
metal contained in the metallio salt solution of the bath upon the metal article...
I can now give to this article so coated any desired form by stamping or otherwise,
or I can proceed to enamel it at once. To enamel it I apply to the surface or
surfaces having the electro-deposited coat a glaze or enamelling mixture. One
mixture which I have found suitable for the purpose is that given in the reissued,
Letters Patent of the United States to F. G. and W.F. Niedringhaus, No. 17,779,.
dated July 3, 1877, although it will be understood that other and analogous
mixtures may be used. After coating the previously prepared article with the
glaze or enamel, I proceed to dry the article and heat it in a muffle or other suit.
able place, according to the usual practice, and at the proper time which will be
determined by practice the article is removed from the muffle and the coat of

page_text: enamel will be found to have adhered firmly to the surface of the article. I thus
produce a merchantable article of manufacture. This article, which I produce,
will in the present instance be coated with a coat of enamel flecked because of the
oxidizing nature of the enamel with mottles of a darker hue, which is ordinarily
known in commerce as mottled enamel. This mottling will be due to the fact that
during the drying of the glaze a metallic oxide is developed upon the metallic
surface of the article, which oxidation may be produced either by the oxidizing
ingredients contained in the enamel or in any other manner.
Whenever the mottled effect is desired, which, as already stated, is produced
either by the use of acid on the steel or iron body, or by the use of an acid in the
enamel, the effect of this acid is not resisted by the very thin film of electro-
deposited metal. Hence, when the acid is applied to the iron or steel vessel.direct,
as described, it oxidizes it wherever applied and eats through or permeates a
portion of the electro-deposited metallic film above it, so that the spot of oxidized
steel or iron can be seen through the glaze coating of the vessel. When the acid
is used in the enamel itself, it permeates the electro-deposited film and reaches the
iron or steel and there produces the oxidizing effect, which is visible through the
glaze. In either case, therefore, whenever my invention is used in the presence
of an acid, the final result is that the film of electro-deposited metal becomes, 80
to say, porous,, adhering firmly to the vessel and to the superposed enamel, and
constitutes a binder, but allowing the oxide of iron to be plainly perceived through
it wherever the acid has taken effect. Hence, I produce, in substance, so: far as
mottling is concerned, an iron or steel vessel, or one of analogous material, which
is covered with a porous or permeable film of electro-deposited metal and upon
which film is placed the enamel.
I have found by experiments that if the electro-deposited metal,, such as cobalt,
is applied in too great a thickness, it, will resist, to a greater or less, extent, the
action of the acid hereinabove described; and this has shown me the value of the
very thin film of clectro-deposited metal in connection with my process. Never-
theless, this part of my invention is applicable also, to the employment of any
porous or perforated metallic sheet between the metal to be glazed and the glaze
itself for producing artistic or ornamental effects.
4
My understanding of the effect of the electro-deposited magnetic metal ou a
surface of metal which is not capable of properly retaining a direct coat of enamel.
is, that the electro-deposited metal enters into such an intimate contact with the
steel or other vessel as not to be separable therefrom; and in turn the enamel or
glaze enters into such an intimate contact with the electro-deposited coat as not to
be separable therefrom. In other words, the said electro-deposited coat forms a
bond that ties or binds the euamel to the steel, where, without such a bond, the
enamel would not properly adhere to the steel or analogous metal.
1
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
:
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ך, ד'
1
1. As a new article of manufacture, an iron or steel article containing a binding-
film of magnetic metal between the body and the: enamel..
2. As a new article of manufacture, an enamelled metallic article, having a film
of cobalt interposed between the metal body and the enamel.
3. As a new article of manufacture, a steel, or iron vessel having thereon an
electro-deposited coat of magnetic metal and superposed. thereupon, a coat of
mottled enamel, substantially as described.
4. In the art of enamelling magnetic metals 'to which the enamel will not properly
adhere, the interposition between the coat of enamel and the said metal or other
article prior to fusing the enamel of a binder of magnetic metal which constitutes
a bond between the metal or other article and the enamel when fused.
5. A metallic vessel or article carrying a perforate superposed film of another.
nietal and upon said film the enamel or glaze, substantially as described...

page_text: 6. A metallic vessel or article partly oxidized provided with a film of electro-
deposited metal and a superposed layer of enamel or glaze, all arranged so that
the enamel or glaze is mottled by the oxidation of the foundation metal, as
specified.
7. As a new article of manufacture, a metallic vessel or article carrying a coat
of mottled enamel on a perforate film of metal, as specified.
8. As a new article of manufacture, a metallic vessel or the like having a porous
or perforate metallic sheet interposed between the metallic body and the enamel
coating, as described.
9. As a new article of manufacture, a metallic vessel or the like having a
permeable metallic sheet. interposed between the metallic body and the enamel
coating, as described.
10. In the art of enamelling metallic articles to which enamel will not readily
adhere, the process which consists in first placing upon such metallic article a
coating of another metal and an acid which is capable of permeating said coating
and oxidizing the body of the article, the resulting oxide in turn permeating said
metal coating, and in applying an enamel to the surface of said coating, as
described.
$1101 1007
A. M. & WM. CLARK,
53 Chancery Lane, London, Chartered Patent Agents.