Improvements in the Manufacture of Tin Plates.
Year: 1889

page_text: Date of Application, 18th Oct., 1889
Complete Specification Left, 27th June, 1890-Accepted, 2nd Aug., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Tin Plates.
I CHARLES ANTHONY BURGHARDT of 35 Fountain Street Manchester in the
County of Lancaster Analytical Chemist do hereby declare the nature of this inven-
tion to be as follows:-
:―
My Invention relates to the tinning of sheets of iron, steel, copper or other
metal or alloy and particularly to the manufacture of ordinary tin plates. In
the ordinary process the sheets of iron or steel are coated with tin by being dipped
into a bath of melted tin as is well understood. The coating thus obtained is more
or less irregular and does not consist of pure tin. It is not possible to obtain a very
thin coating of tin and the hardness or comparative impurity of certain varieties of
tin preclude their use for the purpose so that it is necessary to use certain makes.
In the manufacture of the tinned plates or tinned sheets in accordance with my
Invention I obtain a pure tin coating or an electro deposit upon the sheets using an
electric current derived from a dynamo or suitable apparatus. For the bath I use a
solution of a stannate of an alkali obtained by treating tin or tin ore with caustic
soda or caustic potash and for anodes I use plates slabs or ingots of tin. The tin
used may be pure or be ordinary commercial tin and may be of a quality not suitable
for use in the ordinary process. The said bath may be prepared in accordance with
a former Invention for which Letters Patent Number 659 of the year 1889 were
granted to me, or by the aid of an electric current using a bath of the caustic alkali
solution and anodes of tin the current being maintained until the tin would be
deposited upon the cathodes with sufficient freedom when the plates or sheets to be
coated may be used as cathodes and be coated with tin to the required extent. The
relative weight of tin deposited upon the plates will depend upon the strength or
volume of the electric current and upon the length of time that the plates are subjected
to the action of such current. The required amount of coating may be readily obtained
by leaving the plates in the bath for a longer or shorter time. I have found that the
bath works well at a temperature of 80 to 90 degrees Centigrade. In the cases
wherein the anodes consist of impure tin the accumulation of foreign metals or
matters associated with the tin will necessitate the occasional cleaning out of the bath
or the treatment of the same for the removal of such accumulation but in the cases
wherein anodes of pure tin are used the bath may remain in use for a long period
the anodes being renewed as may be required. Such anodes of pure tin may be
obtained by electro deposition from a bath containing a solution of alkaline stannate
prepared in the manner described in my aforesaid invention of 1889. In cases
wherein such electrode deposit is in the form of powder or particles pressure may be
used to make it cohere to constitute an anode. By means of my Invention I am
able to obtain a coating of uniform thickness with a less proportionate quantity of
tin than is required to properly coat plates by the ordinary process so that there is a
saving in cost due partly to the use of tin obtained at less cost and partly to the fact
that less tin is required to obtain a correspondingly effective coating upon the plate.
Another advantage arises from the fact that a coating of pure tin is obtained and
that in my opinion such a coating will be a better preservative of the foundation
plate than the ordinary impure coating. As the deposit upon the plate is or may be
more or less porous I prefer to subject the plates to further treatment having for its
object to obtain a homogenious coating. For this purpose 1 prefer to use the ordinary
hot grease bath the plates being immersed in the bath and kept in as long as may
be considered to be desirable and being lifted out or being withdrawn by means of

page_text: smooth finishing rollers as preferred. Other means might be used for melting the
coating or for some uses simple rolling might be sufficient but upon this point I have
not certain knowledge at present.
Dated this 17th day of October 1000
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Tin Plates.
I CHARLES ANTHONY BURGHARDT of 35 Fountain Street, Manchester, in the
County of Lancaster, Analytical Chemist do hereby declare the nature of this
invention and in what manner the same is to he performed to be particularly
described and ascertained in and by the following statement, that is to say :-
My Invention relates to the tinning of sheets of iron, steel, copper or other metal
or alloy and particularly to the manufacture of ordinary tin plates. In the ordinary
process the sheets of iron or steel are coated with tin by being dipped into a bath of
melted tin as is well understool. The coating thus obtained is more or less irregular
and does not consist of pure tin. It is not possible to obtain a very thin coating of
tin and the hardness or comparative impurity of certain varieties of tin preclude
their use for the purpose so that it is necessary to use certain makes of tin. In the
manufacture of the tin plates or tinned sheets in accordance with my Invention I
obtain a pure tin coating as an electro deposit upon the sheets using an electric
current derived from a dynamo or suitable apparatus. For the bath I use a
solution of a stannate of an alkali obtained by treating tin or tin ore with
caustic soda or caustic potash and for anodes I use plates slabs or ingots of
tin. The tin used may be pure or be ordinary commercial tin and may be of a
quality not suitable for use in the ordinary process.
The said bath may be
prepared in accordance with a former invention for which Letters Patent number 659
of the year 1889 were granted to me or by the aid of an electric current using
a bath of the caustic alkali solution and anodes of tin the current being maintained
until the tin would be deposited upon the cathodes with sufficient freedom when the
plates or sheets to be coated may be used as cathodes and be coated with tin to the
required extent. The relative weight of tin deposited upon the plates will depend
upon the strength or volume of the electric current and upon the length of time that
the plates are subjected to the action of such current. The required amount of
coating may be readily obtained by leaving the plates in the bath for a longer or
shorter time. I have found that the bath works well when it has a strength equal to
the specific gravity indicated by 1.16 and a temperature of about 80 degrees
Centigrade. When working with a bath of the indicated strength an electric
current of sixty ampères to each square foot of surface to be coated gives good
results. In the cases wherein the anodes consist of impure tin the accumulation of
foreign metals or matters associated with the tin will necessitate the occasional
cleaning out of the bath or the treatment of the same for the removal of such
accumulation but in the cases wherein anodes of pure tin are used the bath may
remain in use for a long period the anodes being renewed as may be required. Such
anodes of pure tin may be obtained by electro deposition from a bath containing a
solution of alkaline stannate prepared in the manner described in the Specification of
my aforesaid Invention of 1889. In cases wherein such electro deposit is in the form
of powder or particles pressure may be used to make it cohere to constitute an
anode. By means of my Invention I am able to obtain a coating of uniform
thickness with a less proportionate quantity of tin than is required to properly coat
plates by the ordinary process so that there is a saving in cost due partly to the use
of tin obtained at less cost and partly to the fact that less tin is required to obtain a
correspondingly effective coating upon the plate. Another advantage arises from the
fact that a coating of pure tin is obtained and that in my opinion such a coating will

page_text: be a better preservative of the foundation plate than the ordinary impure coating.
The amount of tin deposited upon each square foot of the sheet metal can be regulated
to a nicety as the amount of tin deposited in a given time with a current of
known force and a solution of known strength can be readily ascertained so that
the operator can determine how long plates must be subjected to the action of the
current to obtain a deposit of the required relative weight of tin. As the deposit
upon the plate is or may be more or less porous I prefer to subject the plates to
further treatment having for its object to obtain a homogeneous coating. For this
purpose I use the ordinary hot grease bath the plates being immersed in the bath
and kept in as long as may be considered to be desirable and being lifted out or being
withdrawn by means of smooth finishing rollers as in the treatment of ordinary
tinned plates as preferred. Other means might be used for melting the coating or
for some uses simple rolling between smooth rollers might be considered to be
sufficient without the use of the hot grease bath.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is.
1. The process for tinning sheet metal substantially as hereinbefore set forth.
2. In the manufacture of tin plates obtaining the tin as an electro deposit upon.
the plates by the use of a bath prepared from a stannate of an alkali and tin anodes
with an electric current of suitable force substantially as set forth.
3. The use of a bath containing in solution the stannate of an alkali prepared in
accordance with my said Invention No. 659 of the year 1889 and of anodes of tin
in the coating by the aid of electric currents of metal sheets or plates substantially
as set forth.
Dated this 26th day of June 1890
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.