Improvements in Glazing or Enamelling Compounds for Pottery.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Glazing or Enamelling Compounds for Pottery.
We, JAMES NOAD, of High Street, East Ham, Essex, Engineer, and THOMAS
HENRY LEE BAKE, of Coburg Place, Bayswater, London, Gentleman, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to diminish the liability of potters contracting
plumbism in the various operations of applying lead glazes or enamels to earthen-
ware and china, and to diminish the solubility of such glazes and enamels, and,
to this end, the invention relates to an improved lead compound for glazing or
enamelling earthenware and china, and consists in a fritted lead silicate pre-
pared from refined metallic or pig lead, sulphur and silica.
In fritting these ingredients together, the lead is melted in a suitable vessel
or furnace, and to every 112lbs. thereof is added (say) about 40lbs. of a mixture
of equal parts of the sulphur and of the silica, and the whole is vigorously stirred,
resulting in the generation of a sufficiently high temperature to fuse the silica
and frit the mass into a homogeneous slag, which, after being finely ground in
water, washed and dried, is ready for use in an ordinary manner for its intended
purpose.
The stated proportions of the respective ingredients may, however, be varied
according to the required character of the glaze or enamel or of the body of the
earthenware or china to which it is to be applied, and other ordinary glazing
ingredients, preferably an alkaline silicate, may be added to and fritted with
the mixture.
The sulphur should be free from iron, and the silica is preferably used in the
form of "cullet," but, sand, flint or other suitable siliceous material may be used.
The materials may be otherwise fritted together than as above described.
Dated this 24th day of June 1899.
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321, High Holborn, London, W.C.,
Agents for the Applicants.
Improvements in Glazing or Enamelling Compounds for Pottery.
We, JAMES NOAD, of High Street, East Ham, Essex, Engineer, and THOMAS
HENRY LEE BAKE, formerly of Coburg Place, Bayswater, but now of 20, Gayton
Road, Harrow, Gentleman, do hereby declare the nature of this invention and in
[Price 8d.]

page_text: what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The object of this invention is to diminish the liability of potters and others
contracting plumbism in the various operations of applying lead glazes or
enamels to earthenware china and hardware, and, to this end, the invention con-
sists in an improved fritted lead compound, applicable, in lieu of whitelead or
other lead compounds ordinarily used for use in admixture with ordinary leadless
glazing or enamelling bodies in producing lead glazes and enamels, and of
advantage in producing such glazes or enamels of less solubility than those pro-
duced by the use of such ordinary lead compounds.
and
or
The improved lead frit is prepared by fritting together refined metallic or pig
lead, sulphur and silica an alkaline silicate, and, in its preparation, the lead,
melted in a suitable chamber, has added to it a mixture of the sulphur and
silica (the latter preferably in the form of calcined and powder-ground flint)
or of the sulphur and a silicate (the latter preferably in the form of powder-
ground cullet) or of the sulphur and a mixture of the silica and silicate, and the
whole is vigorously stirred. This results in the generation of a sufficiently high tem-
perature to homogeneously frit the whole together, and the resultant mass is
finely ground in water washed and dried, the product constituting the improved
lead frit.
The stated ingredients are preferably mixed in such proportions as will con-
vert the lead into a sulphide throughout which the silica and silicate will be
homogeneously fritted or more or less fused in any required proportion dependent
upon the amount thereof added.
The improved lead frit may be admixed with ordinary leadless glazing or
enamelling bodies in such proportions as whitelead or other ordinary lead com-
pounds are at present admixed therewith, or in any such other proportions as will
produce any required percentage of lead in the so-produced lead glaze or enamel.
The sulphur used in the preparation of the improved compound should be free
from iron, and other silicious materials than those above mentioned may be used
being calcined and powder-ground before being used.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
A lead frit, for use in association with leadless glazing or enamelling bodies
in producing earthenware china and hardware lead glazes and enamels, consist-
aud
ing of a mixture of refined metallic lead sulphur and silica an alkaline silicate
fritted together and ground washed and dried, as set forth.
.. 1000
Or
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321, High Holborn, London, W.C.,
Agents for the Applicants.