Improvements relating to the Enamelling of Iron-plate.
Year: 1891

page_text: Date of Application, 29th Dec., 1891-Accepted, 30th Jan., 1892
COMPLETE SPECIFICATION.
Improvements relating to the Enamelling of Iron-plate.
I, HUBERT CLAUS, of Thale in the Harz, Germany, Managing Director of
The Thale Iron-works Ld. 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 certain new and useful improvements in enamelled iron
plate ware, and has for its object the enamelling of iron plate utensils and the like
in imitation of granite or in mottled or variegated colours by an improved process
which will hereinafter be more particularly described.
The article to be enamelled is first treated in a preliminary bath in order to
provide it with a coating of enamel or glaze. The preliminary coating or glaze
has a similar composition to that of the ordinary metallic ground which is employed
for iron plate ware.
The article thus coated is washed or suitably moistened with a solution of
This solution acts as an agent
Epsom-salts and sulphate of ammonia in water.
for decomposing the next enamel coating which will subsequently be formed upon
the article. This is a grey-coloured glaze or enamel, made of felspar, quartz, borax,
This second enamel
soda, cryolite and saltpetre, diluted or mixed with water.
.coating, in contradistinction to that which is ordinarily used is coarsely ground,
round granular and gritty powder and forms a very thin mixture with the water.
The decomposing agent now acting upon the second coating, causes the same to
assume various thicknesses, and thereby produces an uneven and irregular surface
which imparts a cloudy appearance thereto, and the gritty nature of the enamel
heightens the effect due to the unevenness even after the two enamel coatings have
been fused together by the firing process.
A third enamel coating is now applied to the article which enamel is flexible,
glossy, transparent and of a light grey colour. This enamel consists chiefly of
felspar, fluorspar, quartz, soda, borax, cryolite and saltpetre, these substances
being ground with water to as fine a paste as possible and applied in a thin layer.
It is evident that although the ground or first enamel coating may be of any
colour, such as white or blue, it will be changed in the finished article by reason
of the varying thickness of the second coating and present a different appearance.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
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•
First. The process of enamelling iron plate ware in cloudy or variegated colours,
which consists firstly in coating the article with an enamel ground, secondly in
treating the surface thus coated with a decomposing solution, thirdly in coating
the article with a coarsely-ground grey enamel, and lastly glazing or coating the
article with a thin paste of transparent enamel the nature of which has been
described.
Second. As a new article of manufacture a piece of iron-plate ware the surface of
which has been made rough in various colours or in a speckled manner and
enamelled, and which has in succession been provided with a ground-layer of enamel,
a coating of coarsely ground grey enamel and a transparent glaze or enamel coating
of the kind described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.