A NEW AND USEFUL PROCESS OF COATING IRON AND OTHER METALS WITH COPPER AND OTHER METALLIC SUBSTANCES
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EBENEZER
G. POMEROY, of Cincinnatti, in the County of Hamilton, and State of Ohio,
United States of America, Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain and Ireland,
bearing date at Westminster, the Seventh day of March, in the thirteenth.
year of Her reign, did, for Herself, Her heirs and successors, give and grant.
unto me, the said Ebenezer G. Pomeroy, Her especial licence, full power,.
sole privilege and authority, that I, the said Ebenezer G. Pomeroy, my exors,..
admors, and assigns, and such others as I, the said Ebenezer G. Pomeroy, my
exors, admors, 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 mentioned,.
should and lawfully might make, use, exercise, and vend; within England,,
Wales, and the Town of Berwick-upon-Tweed; and in all Her Majesty's.
Colonies and Plantations abroad, and in the Islands of Jersey, Guernsey,
Alderney, Sark, and Man, my Invention of "A NEW AND USEFUL PROCESS OF
COATING IRON AND OTHER METALS WITH COPPER AND OTHER METALLIC SUBSTANCES;"
in which said Letters Patent is contained a proviso, obliging me, the said
Ebenezer G. Pomeroy, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in

page_text: what manner the same is to be performed, and to cause the same to be enrolled
in Her Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said in part recited Letters Patent, as
in and by the same, reference being thereunto had, will more fully and át large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Ebenezer G. Pomeroy, do hereby declare that the nature of the said Invention,
and the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof (that is to say) :-
My Invention of a new and useful process of coating iron and other metals
with copper and other metallic substances will be clearly understood from the
following description thereof.
Process No. 1.-Immerse the iron, no matter as to its shape or form, in
dilute sulphuric acid for the purpose of cleansing the surface of the article
which is to be coated, and when thus cleansed submit the iron to a brisk
heat, and when dry immerse it in a mixture of clay and water, say, a thin
pulp, a sufficient amount of clay being held in suspension in the water to
leave a thin coating on the surface of the article so immersed, then dry the
iron again over a brisk fire, as before, and it will be in a proper condition for
process No. 2.
Process No. 2.-In order to carry out this process, a suitable bath of
melted metal, copper or its alloys, is provided of a sufficient depth to cover
the article or articles to be coated. This bath is set over a furnace, or so
arranged as to be capable of retaining the copper in a fluid state. The
temperature to which the copper is to be brought to form a union with the
iron admits of a large range, for if the copper be rendered fluid it will unite
with great facility, with the iron. The length of time requisite for the iron
and copper to form a union will be according to the thickness of the article
under operation. For instance, sheet iron will not bear to remain in the bath
longer than a few seconds, and for this reason, so soon as it has become
impregnated with the melted metal in the bath it becomes hot short, and will
break by its own weight, but if it is carefully handled it will as soon as
it has cooled become tough; it may then be passed between rollers as
often it is necessary to reduce it to the desired thickness. The result.
of this annealing process will be a smooth surface, fully equal to the
brightness of pure copper or brass. The time required to coat the iron will
generally be proportioned to the massiveness of the piece, that is, it will
depend on the time necessary to bring up the temperature of the iron to the

page_text: point of alloying with copper.. When in a fluid state the copper is in a con-
dition to commence coating clean iron, and will do so if the piece of iron be
pot so large as to reduce the copper around it to the pasty or solid form. If
the heat of the copper be much above the bare melting point, thick pieces of
iron will be the sooner raised to the required temperature and coated with the
copper. In the first dipping the iron should remain in the bath so long as it
will bear it without becoming hot short, for (observe) the more the copper.
penetrates the iron upon the first dip the greater will be its toughness and
strength, and if it be desired to increase the thickness of the coating you may
make dips in quick succession; this will of course increase the coating upon
the surface. The usefulness of clay as a coating to defend the surface of the
iron from oxydation after it has been cleansed depends in part upon the union
formed between the ammonia generally found in clays, and the. residual
sulphuric acid of the first, that is, the cleansing process; the property of the
acid to act slowly upon the iron is then destroyed or neutralized by the
ammonia in the clay, while the clay itself mechanically protects the surface of
the iron from the action of the air. To be effectually defended by the copper
the iron ought to be thoroughly coated, since if any point of iron 'be left
exposed it will be corroded only the more rapidly on account of its being in;
contact with the less oxidizable metal, which in relation to it acts as an electro-
negative body, just as iron imperfectly tinned is found to corrode faster at the
naked parts than if no tin had been applied to any part of it. This copper-
coated iron will be found useful for many purposes and appliances. It will
be found useful in the sheathing of vessels, in the roofing of houses, and in
marine steam boilers. The saving will be great in employing it as fastenings
of ships, inasmuch as a spike made of iron is much stronger than one made of
copper, but when covered by this process with copper it will prevent the action
of the gallic acid of the wood upon the iron.
Having thus fully described my process of coating and impregnating iron
and other metals with copper or the alloys of copper, what I claim as my
Invention or discovery, and desire to secure by Letters Patent, is,-
First, the before-described process of coating and impregnating iron or
other similar metals in all useful shapes and forms with copper, or any alloy
of which copper forms a part, the said process consisting of cleansing the iron
or other metal with sulphuric or other acid, defending the cleansed surface
with a coating of clay or other aluminous earth, drying the same, and then
plunging the article thus coated into melted copper or an alloy of that metal.
Second, I claim the use of the clay paste to protect the metal from

page_text: oxydation during the process of alloying or coating the metal plates. or pieces.
of metal, as set forth herein..
In witness whereof, I, the said Ebenezer G. Pomeroy, have hereunto
set my hand and seal, this Twenty-first day of August, in the year
of our Lord One thousand eight hundred and fifty.