IMPROVEMENTS IN THE MANUFACTURE OF METALLIC SHEETS, IN COATING METALS, IN METALLIC COMPOUNDS, AND IN WELDING
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Jonn
DAVIE MORRIES STIRLING, of Black Grange, North Britain, Esquire, 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 Thirty-first day of
January, One thousand eight hundred and fifty-one, in the fourteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Davie Morries Stirling, my exors, admors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said John
Davie Morries Stirling, my exors, admors, and assigns, or such others as I, the
said John Davie Morries Stirling, my 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, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF METALLIC
SHEETS, IN COATING METALS, IN METALLIC COMPOUNDS, AND IN WELDING;" in
which said Letters Patent is contained a proviso, that I, the said. John
Davie Morries Stirling, shall cause a particular description of the nature of
my said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her said
Majesty's High Court of Chancery within six calendar months next and

page_text: immediately after the date of the said in part 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, I, the said
John Davie Morries Stirling, do hereby declare that the nature of my said
Invention, and the 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 :-
My first improvement in the manufacture of metallic sheets is the use of
polished rolls to such sheets as are either intended for being coated with other
metals or after such sheets have been so coated; these improvements are
particularly applicable to iron plate either coated or to be coated with tin,
zinc, or other of the more fusible metals. After the plates or sheets of iron
have been cleaned, by pickling or otherwise, in the usual way and as is
well understood, I cause them to be passed between polished rolls, using suf-
ficient pressure to smooth the surface without injuring the quality by producing
brittleness. And I would remark, that as iron is of such different qualities as
regards its ductility, both when hot and cold (according to the district from
which the ore is produced and peculiarities of make), no absolute rule re-
specting the amount of pressure can be given; but a little practice will enable
a workman to judge, and care is to be taken that the rolls are clean. The
plates so polished are then to be dipped in the usual manner into the metal or
alloy intended for the coating. After such plates or sheets have been coated
with any metal or alloy, they are, where a high degree of smoothness is desired,
again passed between polished rolls, the degree of pressure being carefully
regulated so as to avoid the producing brittleness. It is not essential that the
sheets of metal should be passed between the smooth rolls before coating, but
I prefer that such should be the case.
Part of my improvements in coating metals, or alloys of metals, with other
metals or their alloys, relates to coating iron with tin or its alloys. After
having coated the iron with zinc for this purpose, I take iron, previously coated
with zinc, whether such coating has been produced by dipping, as is well
understood, or by deposition from solutions of zinc, and after cleaning the
surface by washing in acid, or otherwise, so as to remove any oxide or foreign
matter which would interfere with the perfect and equal adhesion of the more
fusible metal or alloy into which it is to be dipped, I then melt tin, or any
suitable alloy thereof, and cover its surface with any suitable material, such as
fatty or oily matters, or the chloride of tin, so as to keep the surface of the

page_text: metal free from oxidation; and when the metal is perfectly fluid I dip the
sheet plate or other form of iron, coated with zinc, in the melted metal, and
such dipping is to be conducted in a like manner to the process of making tin
plate, or of coating iron with zine. When a fine surface is required, the plates
or sheets of iron coated with zinc may be passed between polished rolls (as
already described) before and after, or either before or after, they are coated
with tin or other suitable alloy thereof. I prefer in all cases to use pure tin,
known as grain tin, for the coating.
Another part of my Invention, in the coating of metals and alloys of metals,
consists of the covering, either wholly or in part, zinc and its alloys with tin
and such of its alloys as are sufficiently fusible. To do this, I proceed as
follows:-
I take a sheet or plate of zinc (and I prefer such zinc as has been previously
rolled, both on account of its ductility and smoothness, and after cleaning its
surface by immersion in dilute acid, or otherwise-I prefer hydrocloric acid,
but I do not confine myself thereto -I dry such sheet or other form of zine
and then dip it or pass it in any convenient manner through the melted tin or
fusible alloy of tin; and I find that it is desirable to heat the zinc, as nearly as
may be, to the temperature of the melted metal previous to such dipping; and
I recommend that the dipping or passing through be conducted as rapidly as
is consistent with the thorough coating of the zinc, to prevent as much as
possible the zinc being alloyed with the tin, and that the tin or alloy of tin
should not be heated to a higher temperature than is requisite for its proper
fluidity. The metal thus coated, if in the form of sheet plate, or cake, can
then be rolled down to the required thickness; and, should the coating of tin
or alloy be found insufficient or imperfect, the dipping as above described is to
be repeated; and the rolling also, if desired either for smoothing the surface or
further reducing the thickness, is then to be repeated. The process of rolling
zinc when coated. is carried on in like manner to rolling zinc.
Another part of my Invention is the coating of lead or alloys of lead with
tin and its alloys. The process of coating is to be conducted as above
described for the coating of zinc, and the surface of the lead is to be perfectly.
clean; the lead may, like the zinc, be dipped more than once, either before or
after being reduced in thickness by rolling. I employ the hydraulic press.
advantageously in the process of coating lead or its alloys with tin or its alloys,
and as this process is already practised and well understood, as applied to the
coating of lead pipe with tin, I would remark that I use a die or orifice of
such length and width as will allow an ingot, cake, or sheet of lead to be

page_text: formed, and on both sides of this cake or sheet melted tin is to be poured into
a receptacle, as is well understood in the making of pipe; and I would
remark, that where only one side or portion of the cake, ingot, or sheet is to
be tinned, that a partition or division shall be 'placed to confine the melted
tin, so that it shall only be applied to that portion of the lead which is
required to be tinned. Where a smooth surface is required I pass the cake
or other form of lead through a collar of suitable hard and smooth material,
such as hardened steel or iron, kept as cool. as may be, and I recommend
that the ingot or other form should be passed while hot through such collar.
Where a strong coating of tin is required, the lead so,coated is to be passed
through melted tin. Such coated lead or its alloys may be reduced by
rolling, and where the lead so coated is to be reduced to extreme thiness the
further coating is advantageously given after the coated metal has been
reduced to some extent by rolling. Any number of additional contings may
in a similar manner be given, according to the purpose for which the coated
lead is required. In coating lead or its alloys with tin I recommend that
where the coated metal is to be used for purposes where a surface of lead is
to be avoided, pure tin is to be used. Where lead is alloyed with antimony,
zine, tin, or other metal, to render the lead more hard than lead in its ordinary
state, the tin coating may also be somewhat hardened by alloying with zinc or
other suitable hardening metal. Lead and its alloys may also be coated with
tin or its alloys more fusible than the metal to be coated, as follows:-The
cake or other form to be so coated is to be placed, as soon after casting as may
be, into an iron, gun metal, or other suitable mould, or if this cannot be con-
veniently done the surfaces are to be cleaned and prepared for the reception
of the tin or alloy of tin, either by previously tinning the surface or by apply
ing other suitable material to facilitate the union, as heretofore practised. At
one end of the mould a chamber of more than sufficient capacity to contain
a quantity of the metal to be used for coating is to be attached, and may
with advantage form an integral part of the mould, or such chamber may
surround the mould, and by a sluice or valve, or sluices or valves, in such
chamber or chambers the melted metal is to be allowed to run on to the
surface of the metal to be coated, when the metal is to be coated on one side
only. When it is intended to coat the metal on both sides, the vertical position
will be found convenient, and the coating metal is to be poured into a chamber
or chambers attached to the mould, and the melted metal introduced into the
lower part of the mould by opening a sluice or valve, sufficient space being
left on each side of the cake or other form to allow the coating to be of the

page_text: required thickness; and I should recommend such sluice or valve to be of nearly
the width or length of the cake or other form, and that the melted metal
should flow into the bottom of the mould. The mould, of whatever material
it may be, and the cake or other form are to be heated to nearly the melting
point of the coating metal. I am aware that lead has been previously coated
with tin by pouring tin upon the lead, and also by pressure; I do not, there-
fore, claim the coating of lead by such means. The surface of such plate or
cake ought to be smooth and true, and the mould, if horizontal, to be perfectly -
so, and if upright, quite perpendicular, so as to insure in both cases, or in
either case, an equal coating. The surface of the lead should be clean, and
it will be found advantageous to raise the temperature of the lead to a point
somewhat approaching to the melting point of tin or the alloy to be employed
in coating, as by this means the union of the two metals is facilitated. I
would recommend that a somewhat larger quantity of the tin or alloy than is
necessary for the coating the lead or other metal or alloy be employed, and
that, when the requisite thickness of coating has been given, the flow of the
coating metal be stopped, by this means the impurities on the surface of the
tin will be prevented passing through the opening on to the surface of the
cake. The chamber or chambers should be kept at such a temperature as to
insure the proper fluidity of the coating metal. Zinc and alloys of zinc may,
in like manner, be coated with tin and its alloys by employing like apparatus
to that just described when coating lead and its alloys; and it constitutes part
of my Invention thus to coat zine. I do not, however, claim the coating of
zinc with tin, as that has before been done by pouring on tin.
Another part of my Invention consists in coating zinc and its alloys with
tin and its alloys by pressure. I take a suitable piece of zinc or alloyed zinc
and I prefer zinc or alloyed zinc previously rolled, and when it is desirable to
coat such zinc or alloyed zinc on both sides with tin or alloyed tin I take a
piece of rolled tin or alloyed tin of sufficient dimensions to completely cover
the zine, I then subject the zinc or alloyed zinc and tin, or alloyed tin so
placed, to pressure to obtain perfect contact, and for this purpose when in
making sheets I employ rolls and roll out the two metals to the extent
<lesired.
Another part of my Invention relates to the employment of zinc when
welding together plates or other forms of iron, principally applicable when
piling iron. I have found thin sheet zinc placed between the layers to answer
well, but I prefer the use of calamine in the form of powder or paste; in the
latter case the paste may be formed with water, to which a small quantity of

page_text: borax may be added; the paste can then be applied with a brush or otherwise
to the surfaces of the plates or other forms of iron. Additional stiffness and
toughness are produced by this process, and cold short iron I believe to be
more particularly benefitted thereby.
In witness whereof, I, the said John Davie Morries Stirling, have here-
unto set my hand and seal, this Thirty-first day of July, in the year of
our Lord One thousand eight hundred and fifty-one.