IMPROVEMENTS IN COATING METALS WITH OTHER METALS
Year: 1851

page_text: TO ALL TO HOM HESE PRESENTS SHALL COME, we, HENRY
GRISSELL of the Regent's Canal Iron Works, in the County of Middlesex,
Engineer, and THEOPHILUS REDWOOD, of Montagne Street, in the same County,
Professor of Chemistry, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eleventh day of
January. One thousand eight hundred and fifty-one, in the fourteenth year of
Iler reign, did, for Herself, Her heirs and successors, give and grant unto
us. the said Henry Grissell and Theophilus Redwood. our exors, admors, and
assigns, Her especial licence. full power, sole privilege and authority, that we,
the said Henry Grissell and Theophilus Redwood. our exors. admors, and
assigns, or such others as we, the said.Henry Grissell and Theophilus Red-
wood, our exors, admors, or assigns, should at any time agree with, and
no others, from time to time and at all times during the term of years
therein expressed. should and lawfully might make. use, exercise. and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, our Inven-
tion of "IMPROVEMENTS IN COATING METALS WITH OTHER METALS;" in which said
Letters Patent is contained a proviso, that we, the said Henry Grissell and
Theophilus Redwood, shall cause a particular description of the nature of our
said Invention, and in what manner the same is to be performed, by an..
instrument in writing under our hands and seals, or under the hand and sen!
of one of us, to be inrolled in Her Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said in part
.

page_text: recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
Henry Grissell and Theophilus Redwood. do hereby declare that the nature of
our said Invention, and in what manner in which the same is to be performed,
are fully described and ascertained in and by the following description thereof,
that is to say:-
For coating iron with zinc. we use a bath or vessel of suitable shape and
size, which we prefer to he made of iron, in which the zinc is melted by the
application of heat. On the surface of the melted metal we put a thick
stratum of chloride of zinc, made by dissolving zinc in. muriatic acid, and
applying heat until the whole of the water has been driven off; or we put a
mixture of eight parts of chloride of zinc and ten parts of chloride of potassium,
or a mixture of about equal parts of chloride of zinc and chloride of sodium,
or a mixture of about equal parts of dry or anhydrous sulphate of zinc and
chloride of sodium or chloride of potassium. When the zinc and the saline
compound are in a state of fusion, the iron to be coated is put into the melted
zinc through the fused salt, and is kept there for a short time. On taking it
out, if the zinc has not adhered to all parts of it, some powdered salammoniac
is to be sprinkled over it according to the usual method. and the immersion
effected again.
In this process we claim the use of chloride of zinc applied as described
in the previously fused state, also the use, as described, of the mixtures of a
chloride of zinc with chloride of potassium or chloride of sodium, and of
sulphate of zinc with chloride of potassium or chloride of sodium.
For coating zinc, iron coated with zinc, or other metal with a metallic alloy,
we use a bath or vessel of suitable shape and size, which may be made of iron,
in which the alloy is melted by the application of heat. One of the alloys
which we use consists of about twenty-six paris of tin. ten parts of zinc, and
five parts of lead. A stratum of chloride of zinc mixed with about an equal
weight of salammoniac is kept in a state of fusion over the surface of the
melted alloy, and more salammoniac may be added from time to time if the
salt becomes thick: care must be taken not to apply more heat ihan is neces-
sary to keep the alloy and the saline compound fluid. The metal to be coated
is put through the saline compound into the alloy, but it should not be left
there longer than is necessary for effecting the coating. We also use the
alloys commonly known as "fusible metal," in the same way as the preceeding.
The fusible metal which we prefer to use consists of bismuth, lead, and tin, which
may be mixed in the proportions of cight parts of bismuth, five parts of lead,

page_text: and three parts of tin; but other proportions may be used, provided the
resulting alloy will melt at a temperature below four hundred degrees of
Fahrenheit's scale. In this process we claim the use in the manner indicated
of the alloys specified or referred to, and of the method described for coating
metals with such alloys.
For coating iron or other metal with tin or with tin alloyed with lead.-The
iin, or alloy of tin and lead, is melted by the application of heat in a bath or
vessel of suitable size and shape, which we prefer to be made of iron, and a
stratum of chloride of zinc, to which about an equal weight of salammoniac
has been added, is kept in a state of fusion over the surface of the melted
metal; more salammoniac may be added from time to time if the saline com-
pound becomes thick. The iron or other metal to be coated is put into the
melted metal through the salt which floats on its surface, and is kept there
until the coating has been effected. We find it advantageous in conducting
this process, and the same remark applies to the preceding processes, to pass
the metal to be coated several times into and out of the bath, so that the saline
compound used may each time come into contact with the surface to be
coated. We also find it. advantageous in the preceding processes to put the
metal to he coated into a boiling or hot solution of chloride of zinc, slightly
acidulated with muriatic acid, before putting it into the metallic bath. In this
process we claim the use of a mixture of chloride of zinc and salammoniac,
forming a saline compound which is kept in a state of fusion over the surface
of the melted tin, or tin alloyed with lead, in effecting the deposition of these
metals on the surface of other metals.
For coating iron or other metal with silver or with an alloy of silver and
copper. The surface of the iron, or other metal to be coated, is first amalga-
mated, that is to say, it is coated with a thin covering of mercury, which
wholly or partially combines with the metal. forming an amalgam. This may
be effected by any of the well-known processes for the purpose; but we find
the following process to answer very well for amalgamating the surface of iron.
We mix about twelve parts of mercury, one part of zinc, two parts of sulphate
of iron, two parts of muriatic acid, and twelve parts of water in a dish or pain,
to which heat is applied, and whilst the mixture is hot. say at a temperature
of about two hundred degrees, the iron to be amalgamated is put into it. and
he mercury spread or rubbed over the surface of the iron. The silver, or alloy
of silver and copper, is melted in a crucible placed in a suitable furnace, and
he amalgamated metal is put into it and left there until the coating has been
ffected.
We claim the process of coating iron or other metal with silver, or silver

page_text: alloyed with copper, by amalgamating the surface of the metal to be coated,
and then putting it into the melted silver or alloy.
For coating iron with copper, with brass, or with any alloy of copper, with
zinc, Lin, or lead.-The copper or alloy to be used for coating the iron is
melted in a crucible placed in a suitable furnace, and a stratum of borosilicate
of lead (made by fusing together about twenty-four parts of boracic acid, one
hundred and twelve parts of oxide of lead, and sixteen parts of silica) is kept
in a state of fusion over the surface of the melted metal. The iron to be coated
is put into the melted metal through the borosilicate of lead, and is left there
for a short time, or until the coating has been effected: we sometimes cont. the
iron with zinc, or with tin, or amalgamate the surface by the processes already
described, and when thus coated, introduce it into the melted copper, or alloy
containing copper, as above described. We also give to iron a coating of
copper or of brass in the following way-Chloride of copper is put into the
bottom of a crucible or other suitable apparatus, and above it is placed the
iron to be coated. The crucible is covered and put into a furnace, and kept
at a red heat until the chloride of copper has volatized, and the vapour coming
into contact with the iron has left a coating of copper upon it. Instead
of chloride of copper, metallic copper and salammoniac or oxide of copper
and salammoniac may be used. In order to convert the coating of copper
thus produced into a coating of brass, some zinc is put into the bottom of
a crucible, and over it some animal or other charcoal. The iron, with its
copper coating, is then introduced, and the crucible filled up with the charcoal
and a cover closely luted on, with only a small aperture for the escape of
gases. The crucible is now put into a fire and heated to redness, so as
to volatilize the zinc, the vapour of which coming in contact with the copper
will combine with it to form brass.
In this process we claim the use of borosilicate of lead kept in a fluid state
over the surface of melted copper, or brass, or any alloy of copper, with zinc,
tin, or lead, whilst used for coating iron by immersion.
We also claim the process of coating iron with copper, by exposing the iron
at a red heat to the action of fused chloride of copper, or the vapour of
chloride of copper, and of subsequently converting the coating of copper into a
coating of brass, by exposing the former to the action of the vapour of zinc.
In witness whereof, 1, the said Theophilus Redwood, have hereunto set
my hand and seal, this Tenth day of, July, in the year of our Lord One
thousand eight hundred and fifty-one.

page_text: AND BE IT REMEMBERED, that on the Tenth day of July, in the
year of our Lord 1851, the aforesaid Theophilus Redwood came before
our said Lady the Queen in Her Chancery, and acknowledged the Speci-
fication aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stamped accord-
ing to the tenor of the Statute made for that purpose.