Improved Process for Manufacturing Interiorly Enamelled Metal Utensils or Vessels
Year: 1899

page_text: Date of Application, 6th Nov., 1899
Complete Specification Left, 4th Aug., 1900-Accepted, 20th Oct., 1900
PROVISIONAL SPECIFICATION.
Improved Process for Manufacturing Interiorly Enamelled Metal
Utensils or Vessels.
I, JACOB SAMUEL KAUFMANN, of Schillerstrasse 16, Frankfort on the Main,
in the Empue of Germany, Manufacturer, do hereby declare the nature of
this invention to be as follows
This invention relates to an improved process for manufacturing interiorly
enamelled metal utensils or vessels, and 18 for the purpose of providing metal
utensils, such, for mstance, as coffee, tea, or milk pots and the like, with all.
interior coating of enamel
Hitherto it was not possible to manufacture utensils of this kind, enamelled
inside, of copper, silver or the like, but such enamelled vessels are much needed,
as it is difficult to clean the insides of ordinary metal vessels, which would be
an easy matter if they had a resistent inner enamel layer
Contrary to the hitherto hnown enamel processes the present invention
consists in forming fust the enamel layer in form of a self-supporting hollow
body with very thin walls, upon the rough outsides of which a metal coating is
produced, and then 1ound this enamel foundation the metal utensil 16 formed in
the galvanoplastic way; the accessory parts are afterwards put on
The process is as follows
By means of the known enamel or porcelain matter a hollow body with walls
as thin as possible is formed having the inner form of the metal vessel to be
produced The so formed enamel body 18 then buint and glazed on its inside in
the known mannel Upon the outer rough surface a fine layer of precious
metal powder bound with any binding means is then put, whereupon the vessel
18 again burnt to buin in the metal powder whilst the binding means evaporates
In this manner the enamel body receives an outer metal shin joined most
intimately to the rough enamel surface and most intimately united with the
same. The so prepared enamel body 18 then placed in the galvanic bath and is
therein provided with a very thick coating of copper, silvei, or the like which
is thus mechanically fast and inseparably united with the thin precious metal
layer previously applied
After the so produced metal body, provided on its inside with a fast adhere-
ing enamel layer is taken out of the galvanic bath and dried it 18 tuined or
dressed in a suitable manner and the accessories such as the cover, handle, bottom
feet, and the like are soldered or screwed on and the finished utensil decorated
by engraving, etching, polishing and the like.
In a known process for providing clay or glass vessels with a metal covering
the clay or glass vessel is the principal matter and the outer metal layer forms
only an ornamental accessory whilst in the present process the metal vessel 18
the chief matter and the enamel laver only an accessory of the metal vessel
Moreover, the above known process is unlike the present invention as by the
same. it is not possible to effect the absolutely intimate union between enamel
and the metal.

page_text: Upon the clay or glass body of the previously known process, a vainish 18 laid
and thereupon lead ochre 18 rubbed and the vessel is put duectly into the galvanic
bath so as to be coated with the metal laver.
The varnish layer therefore hinders the absolutely intimate junction of the
two materials and produces the further disadvantage that by heating of the
vessel when in use the varnish layer softens, expands and buists the enamel
walls, besides the use of the poisonous lead ochre might be harmful by coming
in contact with the liquid
In the present process metal and enamel are united most intimately without
any foreign intermediate layer and even should there be some cracks in the
glaze there would of course never be any danger that, for instance, copper and
liquid could come into direct contact as the thin precious metal layer covers
the copper on the inside.
The known manner of decorating ceramic objects by a galvano-plastic orna-
mental layer does not affect the piesent invention as the principal purpose is a
decorative one, which is obtained by the effectful contrast of the metal layer
with the colored underground exposed at most parts, and forming a support for
the filigree-like metal decoration, which would otherwise have no hold and
coherence, so that by injury or destroying of the ceramic base, the whole object
would lose its purpose and value
Articles formed by the present process are different as a strong metal layer
forms a hollow body which leaves no spot of its inner enamel coating exposed,
which may become cracked, but never lose its coherence and consequently its
domestic usefulness
Dated this 6th day of November 1899
HERBERT HADDAN & Co.,
Agents to Applicant
Improved Process for Manufacturing Interiorly Enamelled Metal
Utensils or Vessels.
I, JACOB SAMUEL KAUFMANN, of 16, Schillerstrasse, Frankfort on the Main,
in the Empire of Germany, Manufacturer, 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 an improved process for manufacturing interiorly
enamelled metal utensils, or vessels, and has for its object, the provision of said
metal utensils or vessels, (such for instance as coffee, tea or milk pots and the
like) with an interior coating or surface of enamel, porcelain, or the like in
order that they may be more easily and thoroughly cleansed than has hitherto
been possible with those as at present made and used.
It has not hitherto been found possible to manufacture copper, silver, or othei
inetallic utensils or vessels with an interior coating or surface of enamel, porce-
lain, or the like and consequently the proper cleansing of such metallic utensils
01 vessels has always been an operation of great difficulty, to overcome which is
the purpose of my invention hereinafter set forth
My invention differs from the hitherto well known enamelling processes,
inasmuch as by my said invention the body of the said vessel or utensil 18 first.
formed of enamel, porcelain, or the like, having very thin walls, but of any size,
shape o configuration desired, the outer surface of which is rendered rough to
form a key for the metallic powder with which it is subsequently coated as a

page_text: foundation for the outer coating of metal fixed thereonto by the usual and well
known galvanoplastic manner, the accessory parts being subsequently affixed in
the usual way.
In carrying my invention into effect, I produce of any suitable enamel, porce-
lain, or like composition, a hollow body of any size shape or configuration,
moulded or otherwise, but having the formation of the metallic utensil or vessel
to be constructed. The said enamel or porcelain hollow body is then burnt and
glazed on its inner surface in the well known manner, and upon its outer rough
surface a fine layer of any precious or other metallic powder is placed and
caused to adhere thereto in order to produce an outer surface of electric con-
ductivity, the said enamel or porcelain hollow body being then again heated
in order to buin in or incorporate the said metallic powder, while at the same
time causing whatever binding means may have been employed to evaporate
In this manner, the said hollow enamel, or porcelain hollow body receives
an outer metallic coating, layer or skin in the most intimate connection with
its rough outer surface, and the so prepared metallic coated enamel or porcelain
hollow body 18 then placed in a galvanic plating bath, wherein it has deposited
thereon a preferably thin coating of copper or other metal and subsequently a
very thick coating or layer of silver or other suitable metal, which said latter
metallic coatings are thereby electrically made fast and inseparably united to
the said thin or first metallic coating layer or skin previously applied
The metallic utensil or vessel thus produced, with an interior fast adhering
enamel or porcelain surface is now taken from the galvanic bath and thoroughly
dried, after which its metallic portion may be turned or dressed in any suitable
manner, and the required accessories such as the cover, spout, handle, feet, and
the like, be soldered, screwed, or otherwise affixed thereto, when if desired, the
now completed utensil or vessel may be suitably decorated by engraving, etching
or other convenient means.
In the well known processes for providing clay or glass vessels with an outer
metallic covering, the clay or glass vessel is the essential feature, and the outer
metallic layer only an ornamental accessory, whereas in the process according
to my invention, the outer metallic coatings deposited in the galvanic bath
constitutes the utensil or vessel, while the interior enamel or porcelain surface
18 merely an accessory to the same, and moreover by the already existing process
it would be impossible to effect an intimate union between the enamel, porcelain,
or the like and the metal
With the previously known processes, the clay or glass vessel is first coated
with a varnish and lead ochre rubbed thereon, when the vessel is directly placed
into the galvanic bath for the deposit of the metallic layer, and in this process
it has been found that the varnish used prevents the absolute intimate union of
the two materials, and furthermore any heating of the vessel in excess while in
uce, causes the varnish coating to soften, expand, and burst or crack the said
clay, or glass vessel it surrounds, thus making it possible for the contents of the
vessel becoming contaminated by contact with the poisonous lead, whereas in
my improved process the metal and enamel are in intimate union with each
other without any foreign intermediate layer and even should a crack or fissure
occur in the said enamel, porcelain, or the like, no danger could arise from the
contact of the contents of the utensil or vessel with the outer metallic coating, as
the intermediate thin layer of metal would effectually prevent this
Also the known manner of decorating ceramic ware, by a galvanoplastic orna-
mental metallic laver has no bearing on the present invention, as the principle
feature is a decorative effect, obtained by the constrast of the open worked
metallic layer with the exposed and may be colored underground, which forms
the support for the filligree like metallic decoration, and which latter would
otherwise have no hold or coherence, so that if the ceramic base be injured or
destroyed, the object and purpose of the utensil or vessel is lost
The articles constructed according to the present invention are essentially

page_text: different, as the thick outer metallic coating forms a hollow utensil or vessel.
which leaves no portion of its interior enamel or porcelain surface exposed, and
although the latter may become cracked, it never loses its coherence with the
outer metallic coating and consequently its general usefulness and absence of
leakage.
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 18:
1st. The improved process of manufacturing metallic utensils or vessels hav-
ing an interior enamelled surface substantially as herein set forth
2nd. The herein described process of manufacturing internally enamelled
vessels, or utensils, consisting of the production of a vessel of enamel, porcelain,
or the like, coating the said vessel or utensil with an adhering metallic powder,
and subsequently covering the exterior of the said vessel or utensil with a
thick coating of metal or metals by electrolysis, substantially as herein set forth.
2nd. The herein described metallic utensil or vessel having an interior
enamelled surface with an intermediate coating, laver or skin of precious or other
metal, substantially as and for the purposes herein set forth
Dated this 4th day of August 1900.
GEO THOS HYDE.
1, Broad Street Buildings, Liverpool Street, London, E.C.