Improvements in or relating to Protecting Surfaces of Iron or Steel from Oxidation and for Giving them an Ornamental Appearance, Applicable for Gun Barrels and other Bright Work.
Year: 1888

page_text: Date of Application, 13th Nov., 1888
Complete Specification Left, 23rd Feb., 1889
Complete Specification Accepted, 23rd Mar., 1889
Improvements in or relating to Protecting Surfaces of Iron or Steel
from Oxidation and for Giving them an Ornamental Appearance,
Applicable for Gun Barrels and other Bright Work.
I, JONATHAN EWART of 33 Upper Aughton Road, Birkdale, in the County of
Lancaster, Rifle sight maker do hereby declare the nature of this invention to be as
follows:-
--
This invention has for its object a coating for iron and steel that will prevent them
rusting and give them always a neat dull black appearance. The invention will be
valuable for almost all kinds of bright work in connection with iron, especially guns,
pistols and the like. Although designed chiefly with a view to obtaining dull black
surfaces the said surface can be lacquered or otherwise finished so as to form a bright
surface if required.
I carry out my invention in the following manner :-The surface of the article is
brought up to a smooth unflawed condition. It is then washed with dilute nitric
acid until.the grain of the metal begins to be exhibited. The exact point at which
to stop the nitric acid treatment can only be found by experience. The article is
then washed with warm or cold water and is heated by means of gas or other appara-
tus to a dull red heat taking care to avoid oxidation as much as practicable. It is
then immersed in oil, preferably castor oil, and allowed to cool theroin.
It will be obvious that there are other chemicals besides nitric acid that will
develope the grain and therefore I do not wish to bind myself absolutely to develope
it with nitric acid. Furthermore that there are other liquids similar to oil which would
give substantially the same effect if a dull red hot iron or steel were thrown into
them, the effect in all such cases being to cover the surface with a thin but firmly
adherent carbonaceous coating.
Dated this 12th day of November 1888.

page_text: Improvements in or relating to Protecting Surfaces of Iron or Steel
from Oxidation' and for Giving them an Ornamental Appearance,
Applicable for Gun Barrels and other Bright Work.
I, JONATHAN EWART, of 33, Upper Aughton Road, Birkdale, in the County of
Lancaster, Rifle sightmaker, do hereby declare the nature of this invention and in what
manner the same is to be performed, to ho particularly described and ascertained in
and by the following statement :-
This invention has for its object a coating for iron and steel that will prevent them!
rusting and give them always a neat dull black appearance. The invention will be
valuable for almost all kinds of bright work in connection with iron or steel, especially
guns, pistols and the like. Although designed chiefly with a view to obtaining dull
black surfaces, the said surface can be lacquered or otherwise finished so as to form
a bright surface if required.
I carry my invention into effect in the following manner :
The surface of the article is brought up to a smooth unflawed condition by any
suitable means, such as by the use of emory, etcetera. It is then washed and rubbed
with dilute nitric acid until the grain of the metal begins to be exhibited. The
exact point at which to stop the nitric acid treatment can only be determined by
experience and it varies with the nature of the material under operation. In the
case of iron, 3 to 5 minutes is usually sufficient. The acid may be applied by means
of a piece of tow or soft rag. The acid employed may consist of a mixture of equal
parts of water and strong commercial acid, though other proportions may be used
with advantage. The article is then washed with warm or cold water and is wiped
dry. It is then heated, by means of gas or other suitable apparatus to a dull red heat,
care being taken to avoid oxidation as much as practicable. It is then immersed in
oil, preferably castor oil, and allowed to cool therein. The effect of this process is to
produce on the article a dull black surface which will not become rusted, and is not
injured by subsequent oiling.
It will be obvious that there are other chemicals besides nitric acid that will develope
the grain, and therefore I do not wish to bind myself absolutely to develope it with
nitric acid. Furthermore, that there are other liquids similar to oil which would give
substantially the same effect if a dull red hot iron or steel were thrown into
them, the effect in all such cases being to cover the surface with a thin but firmly
adherent carbonaceous coating.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
The process for protecting the surfaces of iron or steel from oxidation, which
F
suitable nolishing

page_text: medium such as emery, (2) washing or rubbing the same with a dilute acid, prefer-
ably nitric acid, (3) washing off the acid, drying and heating the article
to a dull red heat in a suitable apparatus, and (4) immersing it in its heated con-
dition in a quantity of oil or other carbonaceous liquid (preferably castor oil) and
leaving in such liquid until it cools, whereby there is produced upon the article a
thin but firmly adherent carbonaceous coating having a dull black appearance sub-
stantially as described.