CERTAIN IMPROVEMENTS FOR COATING OR COVERING METALS AND ALLOYS OF METALS
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
ARMAND LE COMTE DE FONTAINEMOREAU, of Skinner's Place, Size Lane, in
the City of London, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirty-first day of July, in the eight year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Pierre
Armand le Comte de Fontainemoreau, Her especial licence, full power, sole
privilege and authority, that I, the said Pierre Armand le Comte de Fontaine-
moreau, my executors, administrators, and assigns, or such others as I, the said
Pierre Armand le Comte de Fontainemoreau, my executors, administrators, 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, and in the Islands of Jersey, Guernsey, Alderney,
Sark, and Man, and also in all Her said Majesty's Colonies and Plantations
abroad, the Invention of "CERTAIN IMPROVEMENTS FOR COATING OR COVERING
METALS AND ALLOYS OF METALS," communicated to me by a certain Foreigner
residing abroad; in which said Letters Patent is contained a proviso that I;
the said Pierre Armand le Comte de Fontainemoreau, shall cause a particular
description of the nature of my said Invention, and in what manner the
same is to be performed, to be inrolled in Her said Majesty's High Court of
Chancery within six calendar months next and immediately after the date of

page_text: 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
Pierre Armand le Comte de Fontainemoreau, do hereby declare that the
nature of the said Invention, and the manner in which the same is to be per-
formed, are fully described and ascertained in and by the following statement
thereof (that is to say):-"
The Invention communicated to me of coating and covering metals and
their alloys refers especially to covering tin, zinc, lead, antimony, nickel, cobalt,
cast and wrought iron, and all other metals and their alloys, with a coating of
red or yellow copper: It consists of several parts or distinct operations, and,
though some of them are well known, I will however describe them all
successively for the better understanding of this my Specification:-
Firstly, the process of scouring and cleaning perfectly the pieces to be
coated, in order to free them from every mark of oxide. This might be done
in the usual manner; but the method which I here propose is a decided
improvement. It is effected by a prolonged immersion of the pieces in a con-
centrated solution of the carbonated residuum of cyanuret of potassium, in
which they are well scrubbed and brushed.
Secondly, the process of preparing certain metallic salts, having copper and
prussiate of potash (cyanite of potassium), or copper and cyanuret of potassium,
as constituents.
Thirdly, the process of preparing solutions or baths, in which are immersed
the articles to be coated.
Fourthly, immersion in these baths with the application of a galvanic
current.
The first part of the Invention is already sufficiently explained above.
The second part, namely, the preparation of metallic salts, refers to the
making of two distinct salts. To obtain the salt of copper and prussiate of
potash, 1. dissolve about eighteen ounces of sulphate of copper in five pounds
and a half of distilled water, which must be mixed warm with about eighteen
ounces of prussiate of potash, also dissolved in five and a half pounds of distilled
water; then, with a glass stirrer, the mixture is to be worked until it becomes
a thick red paste, not unlike clots of blood. I compose the second metallic
salt, namely, the salt compounded of copper and cyanuret of potassium, as
follows: I dissolve about eighteen ounces of sulphate of copperin five pounds
and a half of distilled water, which I mix with six pounds and a half of a con-
centrated solution of the carbonated residuum of cyanuret of potassium; and I
take care to stir the composition as I do with the salt herein-before described.

page_text: This salt is like the first before described, a thick paste, but grey, and slightly
inclining to a green rather than a red color. Thus prepared, it dissolves pro-
perly by means of heat in the bath of cyanuret of potassium herein-after
described. I must observe that the oxide, the acetate, in a word all the
soluble salts of copper, may be used for the galvanisation; but as it would be
impossible to employ them all with the same advantage, either on account of
their dearness or inconvenience, I consider that I may limit myself to the two
above mentioned. I prefer this second metallic salt to the first described, for,
in addition to the advantage of not thickening the bath, which checks the
electric current, and of not covering the pieces with a white foam, which cou-
ceals their imperfections, this second salt has also the merit of being much
cheaper.
The third part of the Invention, which is composed of four baths, is prepared
as follows:-The first, which is an alkaline solution of copper, I make by
dissolving in nine quarts of distilled water, by means of heat, four pounds and
a half of fused cyanuret of potassium, and adding to it as much of the salt
compounded of copper and sulphate of potash, before described, as can be
dissolved, and, having filtered the bath, is ready for use. When the bath
grows weak, I add more of the salt, which is completely soluble. The second
bath, which is also an alkaline solution without cyanuret of potassium, is
prepared as follows:-1 dissolve three ounces and a half of prussiate of potas-
sium in five and a half pounds of distilled water, and then saturate this solution
with the salt, having prussiate of potash, or cyanuret of potassium and copper,
for constituents. Then I filter, though this precaution may be dispensed with
and the bath is ready for use. This solution is even preferable to that with the
cyanuret of potassium above described, if the salts of copper could be as easily
dissolved in it. I have given two alkaline baths, though one only is sufficient,
but I can indifferently use either of them with the third bath, herein-after
described, to obtain a fine red copper coating. The third bath is a solution of
about four pounds and a half of sulphate of copper in nine quarts of distilled
water, with the addition of two ounces or rather more of sulphuric acid. I
filter, and this bath is ready for use. This addition of sulphuric acid has the
property of briskering the electric current; and though it may be applied indis-
criminately to all the baths I have described, I have found by experience that
it is most beneficial in the bath of sulphate of copper. I generally add also to
this bath a small quantity of chloride of sodium, which is equally proper for
the alkaline baths above described. The fourth bath I compose by means of
two solutions as follows:-I dissolve, for the first solution, about two ounces of
fused cyanuret of potassium in nine ounces of distilled water. For the second

page_text: solution, I dissolve one ounce of sulphate of zinc in nine ounces of distilled
water. These two solutions must be mixed warm, adding to them from half
to three quarters of an ounce of the double salt of copper before described. I
obtain, by means of this bath, which I use alone and independently of those
previously mentioned, a yellow copper coating.
The fourth and last part of the Invention is, the immersion of the pieces to
be coated in the baths before described with the application of a galvanic
current, which I perform as follows:-I should observe that for the perforated
pieces already cleaned, as before described, it is necessary first to stop up the
holes with cork, or to varnish the inside to prevent a deposition from taking
place in their interiors, which naturally hinder the play of the screw or bolts
which fit into them. Screws and bolts attached to the pieces are varnished
for the same reason.
First immersion of the pieces in the first or second alkaline bath.-In
one of the alkaline baths of copper, before described, I suspend the pieces
well cleaned, as aforesaid, by means of copper wires from transverse
metallic rods in communication with the positive pole of a voltaic battery,
whilst copper plates, which line the interior of the decomposing trough,
are to be connected with the negative pole of the same battery. Care must
be taken to insulate the pieces and shake them occasionally, in order that the
parts in contact with the wire conductors may also be coated. The decom-
posing trough may be metallic or not, but should it be so, it is necessary to
prevent the copper plates forming the anodes or zincodes from touching it.
These plates ought always to be in surface at least equal to the pieces to be
coated. The process may be effected at an ordinary temperature, but if
heated the deposition will be more rapid, and of a better quality. I have
found heating by steam to be the best mode, as it is easily conducted and
regulated. This is contrived with facility by passing a steam pipe under a
vessel filled with sand, in which is placed the decomposing trough. As a
matter of course if the operation is conducted with heat, the same temperature
is to be maintained in cleaning the pieces as that of the subsequent baths; 40°
of Beaume's areometer appears to me the best degree of heat, as it does not
cause a too great expansion of the metal, which manifests itself more especially
in the zinc as being the most sensitive. When the pieces are sufficiently coated,
which is easily known by their fine brilliant red color, they are withdrawn and
plunged into a bath of distilled water at the same temperature as the decom-
posing bath whence they have been taken. They are washed properly, and
are placed again still warm in the second bath. All pieces with concave
surfaces which are to be coated ought to be turned several times in the baths

page_text: during the operation, otherwise the air lodging in the cavities would prevent
the formation of a regular deposit in them.
Second immersion of the pieces to complete the first part of the third
operation. Although in the preceding process, namely, immersion in one
of the alkaline baths, the pieces were covered with a layer of copper of a
fine appearance, their immersion into the solution of sulphate of copper
is indispensable in order to increase it to such a degree of thickness as
may be capable of resisting the action of the acid when the process of
the last final scouring and polishing operation takes place. The mode
of operating before described for the first bath is wholly applicable to
this bath, excepting, however, the following modifications:--In order that
this operation may be perfect, it is necessary to employ a battery with constant
galvanic currents. In this respect that of Mr. Smee seems superior to others,
since it is important that the zinc, or the positive element of the battery, should
correspond as nearly as possible with that of the anodes or zincodes, and that
of the cathodes or platinodes, the perfect harmony of the surfaces being
the best means of obtaining a good galvanization of the pieces. For this
second bath the pieces will be rapidly coated, and a few hours will be suffi
cient to obtain a deposition of the proper thickness. Meanwhile the operator
should carefully avoid a too rapid action, for in this case the deposited metal
would be pulverulent, rugged, of a brown red color, and brittle as glass. A
moderated action, on the contrary, gives a copper deposition of a rosy tint,
perfectly malleable, ductile, and adhering. A too near approach of the
cathodes and anodes would also give a burnt copper of 22 very bad quality;
contact between the pieces, which must always be avoided, would cause great
disorder in the battery. After some seconds of immersion in this bath the
operator should examine them, and if any blotches should appear he ought
immediately to take them out, scrape and brush the blackened parts very
carefully, scour and wash them well in distilled water, and then replunge them
into the first alkaline bath until there remains no trace of the blotches. This
would happen if the pieces had not been well cleaned and scoured previous to
being immersed in either the first or second baths, or if the coppering of these
said baths were incomplete. I must observe that the same precaution should
be taken when the pieces are in the first bath, since the pieces must be
subjected to a second immersion in it if they are covered with blotches or
black marks.
Immersion of the pieces in the fourth bath, to obtain a
copper: This bath, being prepared as before described, I
decomposition trough furnished with red copper anodes.
coating of yellow
pour it into a
I can also use

page_text: anodes of zinc, but in that case I add more of the salt of copper, as above
described. I can allow the sulphate of zine to remain in that bath, as it will
maintain the saturation of it by being dissolved as soon as it is metallically
reformed. operate as I have before stated when speaking of the first and
second alkaline baths, taking care, however, to ascertain carefully the con-
venient degree of electricity by means of the electric regulator. Although it
is impossible in this bath to obtain an unlimited deposition, as in the operation
for obtaining a red copper coating. I can, however, at the end of a certain
time produce a rather strong plating of the yellow copper. I can also vary at
pleasure the color produced in that bath, by adding to it a certain quantity of
those salts which have copper for bases. It may be also sensibly modified by
the addition of solutions of the salts of tin, lead, nickel, cobalt, antimony, and
others. Relatively to the pieces of cast and wrought iron, I slightly tin them
in the ordinary manuer, before immersion in the baths herein-before described,
for the process of obtaining deposits of red and yellow copper. This coating
of tin will very strongly favor the deposition and adhesion of the metals of the
pieces coated, the coating solution will be more effectual and more quickly
obtained. The coating of cast and wrought iron with zinc, according to
Crawford's process, would be still more preferable, since in that connection
zine is highly positive, and will therefore favour still more the deposition. The
perforated pieces of cast or wrought iron, well cleaned as before described,
must, before the tinning or zincing, be prepared as I have stated previous to
their being immersed.
And having now described the nature of the Invention communicated to me,
I wish it to be understood that I make no claim to any of the apparatus, or
to the mode of using them, nor do I confine myself thereto, though I consider
the means above described the best and most simple for performing the
Invention. But what I claim as the luvention communicated to me is,-
First, the mode of cleaning metals, and alloys of metals, by a prolonged
immersion in a solution of carbonated residuum of cynanuret of potassium, in
which they are well scoured and brushed.
Second, the tinning or zincing of cast and wrought iron pieces before pro-
ceeding to obtain either a red or yellow copper coating.
Third, the improved method of depositing a red copper coating on metals
and their alloys by means of an alkaline and an acid bath, as I have described
the operation. And,
Fourth, the improved method of depositing a yellow copper coating on
metals and their alloys by means of a single bath composed of two solutions, as
I have described.

page_text: And such the Invention being, to the best of my knowledge and belief,
entirely new, and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, HerDominion
of Wales, and Town of Berwick-upon-Tweed, and in the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, and also in all Her said Majesty's
Colonies and Plantations abroad, I do hereby declare this to be my Spe-
cification of the same; and that I do verily believe this my said Specification
doth comply, in all respects, fully and without reserve or disguise, with the
proviso in the said herein-before in part recited Letters Patent contained;
wherefore I hereby claim to maintain exclusive right and privilege to the
said Invention.
In witness whereof, I, the said Pierre Armand le Comte de Fontaine-
moreau, have hereunto set my hand and seal, this Thirty-first day of
January, in the year of our Lord One thousand eight hundred and
forty-five.
P. DE FONT (L.S.) AINEMOREAU.
AND BE IT REMEMBERED, that on the same Thirty-first day of January,
in the year above mentioned, the aforesaid Pierre Armand le Comte de
Fontainemoreau came before our Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing therein
contained, in form above written. And also the Specification aforesaid
was stamped according to the tenor of the Statute in that case made and
Provided