Process of Enamelling Iron and other Metals.
Year: 1899

page_text: Date of Application, 22nd July, 1899-Accepted, 23rd Sept., 1899
COMPLETE SPECIFICATION.
Process of Enamelling Iron and other Metals.
I, JULIUS ZERZOG, of Martinlamitz, near Hof, in the Kingdom of Bavaria and
German Empire, Retired Captain of Foot, 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:—
5 The present invention relates to a process of applying a brilliant weatherproof
enamel to iron and other articles. The improved enamel, unlike those at present in
use, is extremely fluid and can be applied by simply dipping into it the article of
iron or other metal to be enamelled. This can be done without a ground of any kind
having to be used, such as is necessary with the enamels now generally employed.
The new enamel, moreover, can be manufactured at a low red heat at which other
enamels cannot be fused.
The precise character of the enamel depends upon the size and thickness of the
articles to be covered. It consists of red lead, borax and flint, and magnesia or spar
may be added, depending upon the degree of hardness or softness desired. Or it may
consist of the above named substances with the addition of a so-called flux (broken
glass), if the enamel is to be very hard and resistant. By the admixture of pig-
ments, any desired colour may be imparted to the enamel.
The enamel is manufactured by putting the substances mentioned above, in
certain proportions, such as will subsequently be stated in detail, in a crucible
of chamotte, (a mixture of unburnt fireclay and powdered seggars) having a small
hole in the bottom. The crucible is then closed with a cover and set in an ordinary
heating furnace to glow, so that the contents may be fused. The mass then flows
as fluid glass into a lower receptacle containing water, where it cools down.
ingredients give a colourless glass, which may be mixed with colouring oxides, as
The fused
desired.
The latter can either be fused at once with the mixture (as much as will go on the
point of a knife is amply sufficient to deeply colour the mass), or after the inass has
been fused and ground. If, however, light colouring oxides are used, they must be
fused at once with the mixture.
The molten mass cools down in the water and has the appearance of broken glass,
being very brittle. It is pounded in a cast-iron mortar and then passed through a
sieve and ground fine in a wet mill until it forins a thin paste (like lime, such as is
used for whitewashing).
The mass so formed is then filled into 8. vessel of size corresponding to that of the
rticles to be glazed. The articles are first pickled and cleaned to remove any rust,
graphite or the like, washed and dried; after which they are dipped, whilst being
urned round, into the mixture, until all parts are evenly covered by the mass.
The articles covered in this way are then set in a warming room at a temperature of
bout 20° Centigrade, so that they may dry rapidly, as otherwise the enamel might
un to one side and so impart to the objects an irregular appearance.
The articles to be enamelled may be dipped into the enamel mass whilst they are
a cold state, but it is preferable first to warm them, as the enamel in this case
theres better, by penetrating into the material.

page_text: After drying in the warm room the articles can be at once or subsequently placed in
a muffle furnace, until they attain a beautiful glaze.
The time required for burning depends upon the thickness of the articles. For
small, thin articles less time is required than for thick massive ones.
The occasional removal from the furnace, to see whether the enamel is adhering, in
no way affects the latter.
Should the enamel coating not be uniform all over, as is often the case with "ivory
white," the article may be re-enamelled. In most cases, however, a single coating is
sufficient.
The enamelled articles can, after burning; be suitably ornamented, e.g. with gold
or silver, and such ornamentation may then be burnt in at a low red heat.
The enamel prepared as described does not chip under blows, but merely shows the
place hit by a mark.
The enamel may be drilled and filed without its appreciably breaking off at the
edges. It is also suitable, on account of its thinness, for use on fine art castings,
where other enamels, by reason of their thickness, would affect the fineness of the
work.
As already stated, the proportions of the mixture of the enamel depend upon the
size and compactness of the articles to which it is to be applied, and may be varied to
meet the degree of hardness or softness required.
or
A readily fusible enamel may be obtained from
(a.) 12 parts red lead
borax and
4
"
4
"
flint (calcined).
(b.) 12
وو
red lead
8
borax and
"
3
"
flint (calcined).
(f.) 10 parts red lead
6
sand
"
5
"
وو
borax and
broken glass.
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:
Process of enamelling iron and other metals, consisting in removing all rust,
graphite and the like from the article to be enamelled, dipping said article, with

page_text: rotary motion, in a mass of enamelling material, to which colouring matter may be
added either before or after fusion, such enamelling material, consisting of
or
(a.) 12 parts red lead
4
4
(b.) 12
283
"
borax and
flint (calcined).
red lead
"
borax and
"
"
flint (calcined).
(c.) 12
245
red lead
دو
دو
وو
borax and
flint.
10
or
(d.) 10
056
red lead
"
borax and
دو
""
flint, with the addition of 2 parts of magnesia
or 3 parts of fluor-spar.
(e.) the mixtures described under (a) and (b) with the addition of to of so-
called flux.
or
(f.) 10 parts red lead
(e) the mixtures described under
called flux.
and (6) with the addition of to of so-
or
(f.) 10 parts red lead
•
"
ப
5
"
4
"
borax and
broken glass
fused in a crucible having a hole at the bottom through which the material is
conducted into a receptacle filled with water, powdered and then ground with water
to a thin paste; then drying the article which has been so treated at a temperature
of about 20° Centigrade in a warming room, and finally burning it in a heating
furnace, all substantially as described.