IMPROVEMENTS IN COATING IRON WITH OTHER METALS
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, EDMUND
MOREWOOD, of Thornbridge, in the County of Derby, Merchant, and GEORGE
ROGERS, of Stearndale, in the same County, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Eighth day of June, in the seventh year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto us, the said Edmund
Morewood and George Rogers, Her especial licence, full power, sole privilege
and authority, that we, the said Edmund Morewood and George Rogers, our
exors, adñiors, and assigns, or such others as we, the said Edmund Morewood
and George Rogers, our exors, adiiors, 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
Invention of "IMPROVEMENTS IN COATING IRON WITH OTHER METALS;" in which
said Letters Patent is contained a proviso that we, the said Edmund More-
wood and George Rogers, or one of us, shall cause a particular description
of the nature of our said Invention, and in what manner the same is to be
performed, to be inrolled in Her said Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
in part recited Letters Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
Edmund Morewood and George Rogers, do hereby declare that the nature of
our said Invention, and the manner in which the same is to be performed,
are fully described and ascertained in and by the following statement thereof,
that is to say:-
Our Invention relates,-
First, to a mode of coating articles of cast iron with tin or other metal as
herein-after described.
Secondly, our Invention relates to a mode of treating articles of iron before
submitting them to molten metal to be coated.
Thirdly, our Invention relates to a mode of treating tin which has becomp
injured or waste in the process of tinning.
Fourthly, our Invention relates to coating sheets of iron with lead or
suitable alloys of lead, but in the case of tin not alloyed to a greater extent
with tin than fifteen per cent., by employing a flux containing sal ammoniac or
chloride of zinc without oil or fatty matters, and further by employing for the
same purpose a flux contain any other suitable metallic salt, as chloride
of tin.
And fifthly, our Invention relates to an after coating of lead or suitable
alloys of lead, but if with tin, to an extent not greater than ten per cent., which
we apply to iron with or without a first coating of other metal, but previously
coated with zinc or an alloy of zinc.
And in order that our Invention may be most fully understood and readily
carried into effect, we will proceed to describe the means pursued by us.
In coating articles of cast iron with molten metals or alloys of metal we
have found that by casting iron into metal moulds the article thus produced
may be coated with metals in a more satisfactory than has been accomplished
when coating articles of iron cast in the ordinary way. And we would here
state that we do not claim the casting of articles of iron into metal moulds,
that being a process well known. In carrying out this part of our Invention,
having carefully cast the articles of iron in metal moulds, we cleanse the
surfaces thereof in any convenient manner, as is well understood, and theu
coat them with metal, either in the usual manner or according to the process
berein described; after cleansing them in acid, if we dry the articles to be
coated we prefer doing so in the manner hereafter described, in order as much
as possible to prevent the prejudicial action of the oxygen of the atmosphere
when drying. The articles of cast iron thus cast in metals moulds are to bo
coated with molten metal in any convenient mode. We would here state that
that we do not claim coating cast iron with molten metal when the articles of

page_text: cast iron have been cast in other than metal moulds; this first part of our
Invention being confined to the combined process of casting iron in metal
moulds, and then coating such articles with molten metal.
We will now proceed to describe the second part of our Invention, which
relates to a mode of treating articles of iron (whether wrought or cast) before
dipping the same into molten metal to be coated. It is well known that if
iron, after the surfaces have been cleansed of scale and other matters, bo
immediately dipped whilst in a wet state into molten metal there is considerable
danger of an explosion, and of the melted metal being projected from the
bath, and in drying articles of iron the surfaces are liable to be injuriously
acted on by the oxygen of the atmosphere in such manner as to prejudice the
coating of metal obtained by the subsequent process of dipping the articles
into the molten metal; and we have discovered that by drying articles of iron
in an atmosphere of vapour, such as will exclude as much as possible the
presence of atmospheric air, we by such means are enabled to obtain dried
surfaces of iron better prepared for receiving a coating of metal when such
surfaces are dipped into a bath of molten metal than when operating according
to the means heretofore resorted to. In carrying out this part of our Invention
we employ an iron trough, which may be made about seven feet long, eighteen
inches wide and three feet deep, but the size of course will vary according to
the nature and description of the articles to be coated; and when sheets or
plates of iron are to be operated on we place three iron racks about eighteen
inches apart across this trough, the racks having upright bars about an incl
apart, between which bars sheets or plates of iron are to be placed on edge,
the object of the bars being to prevent the sheets touching one another. The
racks should reach to the top of the trough and to within six inches of the
bottom of the trough. The bars should be flat and about one and a half
inches broad, with their edges towards the sheet or plates, thus preventing the
sheets or plates touching each other. If the articles of iron are of other
shapes than sheets or plates, racks without upright bars are used, or if upright
bars are employed then they are to be far enough apart to receive the articles
between then. In the bottom of this trough we place sal ammoniac to the
depth of two to three inches, and under the trough we light a fire so as to
heat the sal ammoniae and cause it to give off vapour so as to fill the trough
to the exclusion of the atmosphere. We would remark, that other heated
vapour (which will not seriously affect the iron and yet keep off atmospheric
air from contact with the surfaces of iron which are being dried) may be
used, such as chloride of zinc and others, but so far as our experience goes sal
ammoniae is the best material to be employed. It is desirable to remark, that

page_text: in applying the heat, care is to be observed not to drive off the vapour too fast,
so. as to produce waste, as it is only necessary that the vapour should pervade
the trough to the exclusion as much as possible of atmospheric air. The
plates, sheets, or other articles of iron, whether wrought or cast, may then be
dipped in molten metal, and coated in any convenient manner, as is well
understood, but wo prefer when coating sheets of wrought iron to use rollers,
as was described in our former Patent.
We will now describe the third part of our Invention. In coating iron with
tin it is well known that the workman from time to time remove portions of
waste or spoiled tin from the bath; the tin thus removed, owing to its passing
through the oil or tallow employed as a flux in the tin bath, is mixed with oil
or tallow, This waste or spoiled tin requires to be re-smelted, in which
process waste of tin and expence of smelting, are incurred. Now this part of
our Invention consists in causing the tin thus obtained to be submitted to the
action of beat to raise it to a dull red heat or thereabouts, stirring the same
mixture so that all the oil or tallow may be decomposed. If any fluid tin
should collect in the bottom of the pot during the operation of heating the
waste or spoiled metal from the tin pots, it must, after the waste or spoiled tin
has been removed, be ladled out and granulated or cast into moulds, according
to the purposes for which it is proposed to use it. The waste or spoiled metal
must now be allowed to cool, and when cold put into an earthenware vessel,
and enough of the muriatic acid of commerce poured into the vessel to cover
the waste tin; the length of time which it must be suffered to remain there is
in proportion to the. heat of the mixture. At an ordinary temperature it
should remain about two days, when the acid will be sufficiently neutralized
for our purpose. If an artificial heat is applied, which may be done by intro-
ducing a leaden steam-pipe into the mixture, the solution will be ready for use
in a much shorter time; of this, however, the workman must be the judge.
When the first charge of acid has been sufficiently neutralized and is drawn
off, fresh acid may be added to the remaining scruff or waste tin, by this means
we obtain chloride of tin, which we make use of for tinning metal, as described
in the Specification of our former Patent. Other salts of tin may also be
made by treating the tin in a similar way with other acids.
We will now describe the fourth part of our Invention, which relates to a
mode of coating sheets of iron with lead or any suitable alloy consisting prin-
cipally of lead, but in the case of the alloy of lead and tin then of lead not
alloyed with over fifteen per cent. of tin. We would remark that we are
aware that iron has been before coated with lead combined with tin, in which
cases the tin has formed a very considerable part of the alloy; but it is a well

page_text: known fact that lead or lead only slightly alloyed with tin cannot be advan-
tageously made use of in coating sheets of iron when oil or tallow only are
used for a flux, as the heat of the lead or lead slightly alloyed with tin quickly
decomposes the oil or tallow. And this part of our Invention consists in
applying a flux containing sal ammoniac or chloride of zinc, but not mixed with
tallow, to a bath or vessel containing molten lead or suitable alloys, consisting
principally of lead, but if of lead and tin then not to a greater extent than
with fifteen per cent. of tin when coating sheets of iron with such metal or
alloys thereof, and also in applying a flux containing any other suitable metal-
lic salt, as chloride of tin, for the purpose of coating with the metals or alloys
as aforesaid. In carrying out this fourth part of our Invention we prefer to
use a flux composed of three parts of sal ammoniac and one part of chloride
of zinc without oil or fatty matter; or a flux may be used of one part chloride
of tin and three parts sal ammoniac, with or without one part oil or tallow ;
and the sheets of iron may be immersed in the bath of molten metal in the
ordinary manner; or we prefer to use rollers, as was fully described in the
Specification of our former Patent. In applying the fluxes to the surface of
the molten metal we would remark that we put them on the molten metal
separately, mixing them on the surface of the molten metal; and we can
apply such coating of lead or any suitable alloy consisting principally of lead,
but in the case of the alloy of lead and tin then of lead not alloyd with over
fifteen per cent. of tin, preferring the lead however without admixture in
coating zinced iron or iron which has received a previous coating of some other
metal, as tin, and then a subsequent coating of zinc or any alloy of zinc, in
which case we proceed in the following manner :-The lead being melted in
an iron pot of any convenient size, we cover its surface with a suitable flux, one
composed of two parts chloride of zinc by about one part oil or tallow, with
or without a little sal ammoniac, will answer. This being done we immerse
the articles to be coated in the molten metal, allowing them to remain there
until the surface has become as hot as the molten metal; they are then to be
taken slowly out of the bath and shortly afterwards dipped into water, and
subsequently scrubbed with a brush or with sawdust in order to remove any
flux which may dhere to the surface and to dry the articles. The temperature
of the melted metal should not be allowed to rise much above that of the
melting point of lead, otherwise the zinc is apt to be removed from the
surface of the article to be coated. The best method with which we are
acquainted for ascertaining whether the lead is at a proper heat is by taking a
thin bar of zine which is alloyed with five per cent. of tin and introducing it
into the molten metal, if it quickly melts the metal is too hot, if it does not

page_text: meit the heat is about right, provided the lead is properly fluid. Care must
be taken not to allow the articles to remain in the molten metal longer than
is necessary for their taking the coating. When it is desired to harden the
coating of lead we have found it desirable to alloy it with a small quantity of
antimony, but this adds to the expence.
Having thus described the nature of our Invention, and the best means we
are acquainted with for performing the same, we would have it understood
that we do not confine ourselves to the precise details herein described, provided
the peculiar character of either part of our Invention be retained. But what
we claim is,
First, the mode of coating cast iron with other metal by combining the
processes of casting articles of iron in metal moulds, and then coating such
articles with molten metal.
Secondly, we claim the mode of drying articles of iron before immersing
them in molten metal to coat them by subjecting such articles to heated vapour,
in order to exclude as much as possible the presence of atmospheric air.
Thirdly, we claim the mode of heating the waste tin obtained when tinning
iron and of subjecting it to muriatic or other acid, thereby converting it into
a useful salt of tin, as chloride of tin, to be used as herein described.
Fourthly, we claim the mode of coating sheets of iron with lead, or any
suitable alloy consisting principally of lead, but in the case of the alloy of
lead and tin then of lead not alloyed to a greater extent than with fifteen per
cent. of tin, by employing a flux containing sal ammoniac or chloride of zinc
without fatty matter or oil. And further, we claim the mode of coating with
lead, or any suitable alloy consisting principally of lead, but in the case of the
alloy of lead and tin then of lead not alloyed to a greater extent than with
fifteen per cent. of tin, by employing a flux containing any other snitable
metallic salt, as chloride of tin. And,
Fifthly, we claim the coating of iron, or iron which has received a previous
coating of some other metal, as tin, and then, whether iron or coated iron, a
subsequent one of zinc or a suitable alloy consisting principally of zinc, with
lead or suitable alloys, consisting principally of lead, but in the case of tin and
lead to an extent not greater than per cent., not however claiming for the use
of any particular flux in relation to this coating.
In witness whereof, we, the said Edmund Morewood and George Rogers,
have hereunto set our hands and seals, this Seventh day of December,
in the year of our Lord One thousand eight hundred and forty-four.
EDMUND (LS.) MUKEWOOD.
GEORGE (L.s.) ROGERS.

page_text: AND BE IT REMEMBERED, that on the Seventh day of December, in
the year of our Lord 1844, the aforesaid Edmund Morewood and George
Rogers came before our said Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing therein
contained and specified, in form above written. And also the Specification
aforesaid was stamped according to the tenor of the Statute made for that
purpose.
Enrolled the Seventh day of December, in the year of our Lord One