PROCESS AND APPARATUS FOR ELECTROPLATING, AND GENERALLY APPLICABLE FOR TREATING METALLIC SURFACES BY ELECTROLYSIS
Year: 1884

page_text: I, HERBERT JOHN HADDAN, of 67, Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of said Invention for PROCESS AND
APPARATUS FOR ELECTROPLATING, AND GENERALLY APPLICABLE FOR TREATING
METALLIC SURFACES BY ELECTROLYSIS," a communication to me from abroad by
Dr. Gottfried Wagener and Curt Netto, Professors at the Imperial Japanese
University, of Tokio, Japan, to be as follows:-
=
This process has for its object to cover articles of any size with a pure metallic
coating by galvanising or electroplating, and also to etch or oxidise the metallic
surface of any article without immersing such article into the corroding liquid or
electroplating bath."
"
For this purpose the article to be electroplated or oxidised is made to form the
fixed pole of a galvanic battery, while the other pole together with the corroding
liquid is made portable so that it may be conducted over the whole surface of the
article and subject all parts of the same to the galvanising or electroplating action
until the desired effect is attained.
For electroplating, the anode, in this case the movable pole, consists of the metal
to be deposited as in the usual process.
The solutions employed in this process are the same as in the usual process.
The process of covering a large plate of iron with zinc, for instance, is carried
out as follows:
The iron plate is connected with the negative pole, while the anode, that is to
say the movable pole, consists of a plate of zinc of suitable shape and handy
dimensions.
The zinc plate is provided on one side with a flannel pad, and on the other side
with a handle, and connected in suitable manner with the positive pole of a
galvanic battery or any other generator of electricity by means of Hexible
conducting wires.
The saturation of the pad with the solution of zinc is effected either by repeated
immersion in fresh solution or by a continuous supply controlled and arrested
according to requirements.

page_text: If the pad is saturated by a continuous supply-current, the zinc plate is
perforated and the current passes through the hollow handle, connected at the free
end by an indiarubber tube with the receptacle containing the solution, while the
other end passes through a hole in the zinc plate and is connected with the pad.
I preferably use for this purpose a solution of chloride of zinc as neutral as
possible that is to say which does not attack zinc even when heated.
If the surface of the article to be treated is uneven, it is preferable to use a pole
having the shape of an elastic brush, instead of a plate, and to conduct the current
through flexible metallic wires forming part of the brush.
The nature of the metal forming the brush depends on the object to be attained
as in analogous processes carried out in the usual manner.
The movable bath or pole with the liquid to be decomposed may also be
conducted over the surface of the article by means of suitable mechanisms.

page_text: I, HERBERT JOHN HADDAN, of 67, Strand, in the City of Westminster, do
hereby declare the nature of said Invention for "PROCESS AND APPARATUS For
ELECTRO-PLATING, AND GENERALLY APPLICABLE FOR TREATING METALLIC SURFACES
"
BY ELECTROLYSIS," a communication to me from abroad by Dr. Gottfried Wagener
and Curt Netto, Tokio, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :---
The purpose of this invention is to give, by means of the galvanic fluid, a pure
metallic coating to objects of any size, (but especially large ones) or generally to
subject the surface of such objects to electrolysis without its being necessary to
immerse the object in the conducting fluid or so called bath.
This is attained by the objects in question forming the one fixed pole of the
battery, while the other pole, with the conducting fluid, is moveable and can
therefore, be passed over the surface of the object, so that every point of the same
can be exposed for a sufficient time to the galvanic action until the desired result is
attained.
In the case of a metallic coating, as in the usual process, the anode (in our case
the movable pole) will consist of the metal to be deposited.
As regards the nature of the solution, the same rules apply as in the usual
process.
The following example may serve as an illustration. A large iron plate is to be
coated with zinc.
In this case the plate would be connected with the negative pole; the anode, or
movable pole, would consist of a zinc plate of suitable form and manageable
dimensions.
This zinc-plate a (see accompanying drawing) is covered, on one side, with a
flannel pad 61, and provided, on the other, with a handle, and is connected, in a
suitable manner, by flexible conducting wires d, with the positive pole of the
battery or some other electrical generator.
The pad is saturated with a solution of zinc, either by steeping it repeatedly in
a fresh solution, or by a controllable continuous supply which can be stopped at
pleasure.
In the latter case, namely, when the pad is fed by a constant supply of the
solution, the zinc plate a is pierced, and the supply takes place through the hollow
handle, which is connected at its open end with the trough containing the solution,
by means of the gutta-percha tube e, and at the fore end, extending into the
opening of the zinc plate, it is connected with the flannel pad.-A good solution,
in this case, is a solution of chloride of zinc, perfectly neutral, so as not to attack
zinc even in a hot state.
The deposit obtained in this way, adheres as well to the iron as that produced
by the dry process, whereas, as is well known, the galvanic zinc deposit produced
by immersion does not possess this property.

page_text: In cases where the surface of the object is very irregular it is advisable to employ
a pole formed like an elastic brush, instead of an anode consisting of a plate, and
which conducts the current through flexible metal wires contained in the brush.
The nature of the metal in the brush depends upon the purpose to be attained,
as in analogous processes in the old way.
The moveable pole, with the conducting fluid, can also be carried over the surface
of the object under treatment by means of suitable mechanism-As regards the
application of the process, the following cases may be instanced.
1. Coating armour plates with zinc, the principal advantages being-
a-that the large heavy plates need not be immersed in a metal bath.
b-that the zinc coating can be conveniently renewed without moving the
plates.
2, Large pieces of machinery, cannon, perhaps even large iron structures, could
be covered with a coating of zinc.
3, Cast iron can be covered with zinc or copper, (for instance lamp posts) and it
is also possible to repair the ccating on the spot, as one would renew a coat of
paint.
The process can also be applied
4, to embellish ornamental zine castings (large objects) by coating them with
copper or other metals.
5, generally speaking, objects can receive a metallic coating of silver, gold,
nickel, zinc &c, either for the sake of protection, or for embellishment:
a when their dimensions do not admit of their immersion into a bath.
b-when their position excludes or renders difficult the process now in use.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The process of providing objects with a metallic coating, which consists in
passing over the objects a pervious body containing the galvanic bath, and
connected with the conductor of a battery; so that the object to be coated forms
one pole, while the portable bath constitutes the other pole of the battery.
2. The apparatus, composed of the metallic disc a, the pad b, and the handle c—
connected in a suitable manner with the corresponding pole of a battery or with
soine other generator of clectricity.
3. The employment of an elastic brush, instead of the plate a-conveying the
current through flexible metal wires contained in the brush.
4. The saturation of the pad or the brush, by repeated immersion in a fresh fluid
or conducting solution, or by conveying the latter to it in a continuous and
controllable manner.
H. J. HADDAN.
By Herbert & Co., Agents,
67, Strand.