Improvements in Electro-depositing Copper, Brass, and Bronze.
Year: 1891

page_text: Date of Application. 8th Apr., 1891
Complete Specification Left. 8th Jan., 1892-Accepted, 13th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electro-depositing Copper, Brass, and Bronze.
We WILLIAM HENRY WALENN of No. 9, Carleton Road Tufnell Park
London N. Consulting Electrician and ILLIUS AUGUSTUS TIMMIS of No. 2 Great
George Street, Westminster London S.W. Civil Engineer, do hereby declare the
nature of this invention to be as follows:-
--
This invention consists in the use of free ammonia in alkaline solutions for
depositing copper brass and bronze by means of electricity, in conjunction with means
for preventing the escape of the ammoniacal gas during electro-deposition and, if
desired, for using the solution under pressure. By this method of working ordinary
alkaline solutions the application of heat is avoided, thick and adhesive coatings
can be given to iron, for instance, and the solution is kept practically in the same
condition for a long period of time. Čast and wrought iron, steel, zinc and other
metals that readily dissolve in acids may be advantageously coated with copper,
brass and bronze by means of this invention.
Another part of this invention consists in the use of commercial potassium
cyanide containing, within reasonable limits, 40 per cent. of real potassium cyanide
(K.C.N. or KCy.) in alkaline copper, brass and bronze solutions.
The following ingredients, proportions methods of making and of working
solutions according to this invention are given as parts of the invention as well as
examples by which all other alkaline coppering, brassing or bronzing solutions may
be made and worked.
It is preferable to make a solution hereinafter called the "solvent solution" then
to charge this solution with the metal to be deposited by means of electricity, using
a large anode and the smallest possible cathode and to treat the solution subse-
quently in any way that will increase the amount of metal, per gallon, in solution
or otherwise promote its efficiency.
,,
In the case of copper, 2 lbs. avoirdupois of 40% potassium cyanide are dissolved
in one gallon of water. One ounce of neutral ammonium tartrate is dissolved
It is best to make the
in 5 ounces of water and added to the cyanide solution.
neutral ammonium tartrate solution by adding ammonia water to a solution of
tartaric acid taking care that the resulting solution has the proper amount of water
and that it is not acid in its reaction on test paper. To the solution containing the
cyanide and tartrate add 5 ozs. of ammonio-cupric oxide and the resulting solution
is the "solvent solution which is to be charged with copper, in the proportion of
between 2 and 3 ozs. per gallon. When the solution is charged sufficient ammonio-
cupric oxide is to be further added to the brown solution until it is of a clear sea-
green color. The solution is entirely made in the cold and charged in a closed
vessel, the vessel having a gas tight cover through which or through any other
When the
part of the casing the conducting wires pass to the anode and cathode.
solution is made, 6 ozs. of ammonia water per gallon are added to the solution and
the cover or a false cover is thenceforward kept on the depositing vessel. The
deposition is done in the usual way.
The preferred proportions of the solvent solution for brass are equal parts of the
cyanide and tartrate solutions. For bronze 6 parts of the cyanide and one part of
the tartrate. The method of charging, adjusting and working the brass and bronze
solutions is exactly the same as for the copper solution.
When the solution is used under pressure the pressure may be created by a head
of liquid or by forcing air or ammonia into the depositing vessel. A moderate
pressure say 2 lbs. per sq. inch will suffice to give a good coating but the pressure
may be increased to any amount that is found to be serviceable.

page_text: This invention yields a tough homogeneous, non-porous, bright and adhesive
metallic coating.
Dated this 8th day of Anril 1891
W. H. WALENN.
I. A. TIMMIS.
COMPLETE SPECIFICATION.
Improvements in Electro-depositing Copper, Brass, and Bronze.
We WILLIAM HENRY WALENN of No. 9 Carleton Road; Tufnell Park,
London N. Consulting Electrician and ILLIUS AUGUSTUS TIMMIS of No. 2 Great
George Street Westminster London S.W. Civil Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention consists in the use of free ammonia in alkaline solutions for
depositing copper, brass and bronze by means of electricity, in conjunction with
means for preventing the escape of the ammoniacal gas during electro-deposition
and, if desired, for using the solution under pressure. By this method of working
ordinary alkaline solutions the application of heat is avoided, thick and adhesive
coatings can be given to iron, for instance, and the solution is kept practically in
the same condition for a long period of time. Cast and wrought iron, steel, zinc
and other metals that readily dissolve in acids may be advantageously coated with
copper, brass and bronze by means of this invention.
Another part of this invention consists in the use of commercial potassium
cyanide containing within reasonable limits 40% of real potassium cyanide
(K.C.N, or' KCy) in alkaline copper, brass and bronze solutions.
The following ingredients, proportions, methods of making and of working
solutions according to this invention are given as parts of the invention as well as
examples by which all other alkaline coppering, brassing or bronzing solutions may
be made and worked.
It is preferable to make a solution hereinafter called the "solvent solution," then
to charge this solution with the metal to be deposited by means of electricity, using
a large anode and the smallest possible cathode and to treat the solution subse-
quently in any way that will increase the amount of metal, per gallon, in solution
or otherwise promote its efficiency.
In the case of copper, 2 lbs. avoirdupois of 40 per cent. potassium cyanide are
dissolved in one gallon of water. One ounce of neutral ammonium tartrate is
dissolved in five ounces of water and added to the cyanide solution. It is best to
make the neutral ammonium tartrate solution by adding ammonia-water to a
solution of tartaric acid, taking care that the resulting solution has the proper
amount of water and that it is not acid in its reaction on test paper. To the
solution containing the cyanide and tartrate add five ounces of ammonio-cupric
oxide and the resulting solution is the "solvent solution" which is to be charged
with copper, in the proportion of between two and three ounces per gallon. When
the solution is charged, sufficient ammonio-cupric oxide is to be further added to
the brown solution until it is of a clear sea-green colour. The solution is entirely
made in the cold and is charged in a closed vessel, the vessel having a gas tight
cover through which or through any other part of the casing the conducting wires
pass to the anode and cathode.
When the solution is made, 6 ounces of ammonia water per gallon are added to
the solution and the cover, or a false cover is thenceforward kept on the depositing
vessel. The deposition is done in the usual way.
The preferred proportions of the solvent solution for brass are equal parts of
the cyanide and tartrate solutions. For bronze, 6 parts of the cyanide and one
part of the tartrate. The method of charging, adjusting and working the brass
and bronze solutions is exactly the same as for the copper solution.

page_text: When the solution is used under pressure the pressure may be created by a head.
of liquid or by forcing air or ammonia into the depositing vessel. A moderate
pressure, say 2 lbs. per square inch, will suffice to give a good coating but the
pressure may be increased to any amount that is found to be serviceable.
This invention yields a tough, homogeneous non-porous, bright and adhesive
metallic coating.
Free ammonia exactly becomes the substitute of heat in this invention. Although
it does not expand the metal to be deposited upon, as heat does, its power of
diffusibility and the extreme minuteness of its molecules enables it to confer upon
the solution the power of permeability, so that the metal deposited from it enters
into the pores of the iron or other underneath metal and accomplishes what heat
does in former inventions, for the complete and perfect adhesion of the coating to
the underneath metal. The presence of ammonia also confers conductibility upon
the solution and euables a lower electro-motive force to be used than could
advantageously be done in any previous process. The use of free ammonia aids
materially the non-porous and compact character of the deposit and makes it
uniform throughout the entire cathode however large it may be. It also makes
the solution equally dense throughout, both at the upper and at the lower part.
It
tends to clean the article or cathode as a final and infinitesimal cleaning from the
minute remains of the acids and other substances used in the ordinary cleansing
processes converting them into soluble substances which are perfectly innocuous to
the working of the solution. Further, the use of free ammonia as described, tends
to render the solution perfectly electro-neutral, so that the cathodes may be left an
indefinite time in the bath before the electric circuit is completed. It renders the
solution active in its soluble action upon the anodes during the passage of the
electric-current so that there is no danger of the solution becoming weak from
want of the proper amount of metal in solution. It preserves the solution in
working order. In the case of brass and other alloys it preserves the color of the
deposit and the relative proportion of the constituent metals of the alloy.
Ammonia also tends to prevent saline crystalline or pulverulent deposits in the
bath or on the anode or cathode.
The electric power used may be advantageously a dynamo-machine in the day
time and, if it be desired to continue the deposit during the night, accumulators.
The electro motive force may be from one volt up to six volts. If necessary two
baths may be coupled in series and the accumulators coupled up in multiple arc, so
that they give only the electro motive force of one cell. Or the solution may be
worked entirely by accumulators. Or by the cast-iron and leaded amalgamated
zine battery set forth in the Transactions of the British Association for 1849
(Birmingham Meeting) and in the article Electro-Metallurgy in Maspratt's
Chemistry as Applied to Arts and Manufactures A.D. 1879
The principal diluent in cyanide of potassium containing 40 per cent. of real
cyanide (K.Cy.) and 60 per cent. of extraneous matter is potassium carbonate.
This particular quality of cyanide is found to be necessary for the perfect working
of the solution as it preserves the balance and constancy of the solution. The
purer cyanides tend to dissolve the anode during the times that the solution is out
of work or the electric current not passing. This particular quality (40 per cent.
real cyanide) only dissolves the anodes during the passage of the electric
current.
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 I
claim is :-
-
First The use of free ammonia in an enclosed depositing vessel for depositing
metals by ac alkaline solution, as described and for the purposes set forth.
Secondly The use of free ammonia in an enclosed depositing vessel in the
coppering solution and the other solutions, the methods of making which are given
and described for the purposes set forth.

page_text: :-
Thirdly The use of pressure in combination with the addition of free ammonia
(to the solutions mentioned) and the enclosed vessel as described and for the
purposes set forth.
Fourthly The use of 40 per cent. cyanide (more or less) but within reasonable
proximity to that degree of purity, for copper, brass or bronze solutions.
Dated this 8th day of January 1892.
W. H. WALENN.
I. A. TIMMIS.