AN IMPROVED METHOD OF PLATING METAL, CHIEFLY DESIGNED FOR THE APPLICATION OF A COATING OR COVERING OF GOLD, SILVER, OR PLATINA UPON THE SURFACES OF BASER METAL
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Abraham Van Winkle at the Office
of the Commissioners of Patents on the 29th January 1878.
"
ABRAHAM VAN WINKLE, of Queen Victoria Street, in the City of London. 'AN
IMPROVED METHOD OF PLATING METAL, CHIEFLY DESIGNED FOR THE APPLICATION
OF A COATING OR COVERING OF GOLD, SILVER, OR PLATINA UPON THE SURFACES OF
BASER METAL."
This Invention relates to an improved method of plating metal, and is designed
to provide means for producing articles or objects coated or covered with gold,
silver, platina, or other metals, which articles will be more durable, and at the same
time less costly than those which are coated by any of the methods hitherto
used.
In covering or coating objects made of the baser metals, such as brass, copper,
iron, zinc, or the like with gold, silver, platina, or other superior metals, whether
by means of plating or electro-deposition, it has heretofore been the practice tó
deposit the metal which is to form the coating or covering upon the baser metal
direct, without any intermediate material between them. Therefore, when the
coating of gold, silver, or the like is a thin one it soon wears off in use, and the
underlying baser metal becomes exposed at the part or parts of the surface at
which the superior metal is worn off, the result being that the said object or article
becomes comparatively worthless, and in some cases totally unfit for the use for
which it was constructed. It has consequently been necessary to deposit a com-
paratively thick layer of the coating' metal, which causes the articles or objects
thus covered to be correspondingly costly in manufacture.
My said Invention consists in providing an intermediate layer of nickel between
the brass, copper, or other base metal of which the article or object is constructed,
and the gold, silver, or other superior metal which is to form the coating or covering
thereof.
It is well known that nickel is very hard, and the facility with which it may be
deposited upon other metals renders it peculiarly suitable for the purposes of my
Invention.

page_text: It will be readily understood that metal covered with this intermediate coating
of nickel need not have so thick a layer of the superior metal as it must have
when the latter is deposited in the usual manner, inasmuch as when the gold,
silver, or other covering metal wears off at parts of the surface of an article or
object coated according to my said Invention, the underlying intermediate layer of
nickel remains. to protect the baser metal beneath it from exposure, and the article
or object is not deteriorated in appearance, nor is it in the slightest degree
less suitable for the purposes for which it was constructed than when first
manufactured.
I may coat or cover the said baser metal with the said intermediate layer of
nickel in any convenient manner, but prefer to do it by means of a solution of
double chloride, or double sulphate of nickel and ammonia; and in subsequently
covering the nickel I prefer to use the cyanide solutions of silver or gold when the
last-named metals are required as the outer coating, but any other solutions of
these last-named metals may be used.