Improvements in Producing Designs upon Metal by Etching.
Year: 1893

page_text: Date of Application, 22nd Nov., 1893
Complete Specification Left, 22nd Aug., 1894-Accepted, 27th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in Producing Designs upon Metal by Etching.
THOMAS PULLING, Practical Church and Domestic Decorator, 120 Goldhawk
Road, Shepherds Bush, London W. do hereby declare the nature of this invention
to be as follows:-
Improvements in producing designs upon metal by etching without the aid of
machinery or metal tools of any kind, for organ and other pipes, panels for furniture
wall or ceiling decorations, church tablets, panels &c. fascias advertisment tablets,
stencils, door plates, or decorative work of any kind in metal, where low relief is
required.
Any pattern required to be etched is first painted on the metal in strong
embossing black, wax or other protective medium. When dry, it is placed in a bath
of acid the strength of which is regulated to suit the depth the pattern may be
required to be raised or sunk.
Dated this 7th day of August 1893
THOMAS PULLING.
Improvements in Producing Designs upon Metal by Etching.
I, THOMAS PULLING, of 43, Richmond Gardens, Uxbridge Road, Shepherds
Bush, in the County of Middlesex, formerly of 120, Goldhawk Road, Shepherds
Bush, in the county aforesaid, Practical Church and Domestic Decorator, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
My invention relates to a new or improved method for producing letters and
designs upon metallic surfaces in a cheaper and more expeditious way than
heretofore, and consists essentially in painting or otherwise forming the letters or
designs on the metallic surface in an acid resisting medium and then biting or
etching the design by means of a suitable acid.
The metal I prefer to use is rolled sheet zinc, on this I paint the parts of the
designs or letters which are required to be in relief with an acid resisting medium,
such as brunswick black, but I prefer to use what is known in the trade as "strong
embossing black." When the painted parts are dry, and the back and edges of the
plate have also been covered and protected with an acid resisting medium, I place
the plate into a bath of dilute acid preferably hydrochloric acid, the strength of
the acid depending upon the design, the thickness of the plate and the relief
required. For instance with an intricate design with fine lines required to be in
relief, a weak acid bath would be used, but where the design is bold and a good
relief desired, a strong bath is desirable. In some cases it may be desirable to
produce two or more different degrees of relief in the same plate, this I accomplish
by first protecting with the acid resisting medium all portions of the design to be
in relief, then biting in to the desired depth in the acid bath after which the
resisting medium is removed, preferably by a suitable solvent, the plate is then
again covered with resisting medium leaving only those places bare that are
required to be of a greater depth; it is then re-bitten in the acid bath to the
desired depth.

page_text: Plates so ornamented are particularly adapted to receive coloured enamels or
paints on the bitten portions of the design, as the action of the acid on the metal
produces a good key for holding the enamel or paint, and in some cases I may
gild with gold, silver leaf, aluminium leaf or the like, the portions of the designs
or letters in relief. Or I may sometimes electrically deposit brass, nickel, copper,
gold or silver, on the said plate when finished.
I have above described the invention with reference to sheet zinc, but it will be
understood that sheet copper or other metal may be employed with a slight
variation in the mordant or acid used for etching or biting in the design; for
instance with copper I prefer to use diluted nitric acid.
This method of producing letters and designs upon metallic surfaces is specially
applicable for metal sheets used in the manufacture of organ pipes, furniture panels,
walls or ceiling decorations, church tablets, fascias, advertisement tablets, door plates
and similar metal work where low relief is required.
I wish it to be particularly understood that I do not limit myself to the precise
details of the process herein before described, but that I hold myself at liberty to
make such changes and alterations as fairly fall within the spirit and scope of my
invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
(1.) The production of designs or letters upon metal, as set forth.
(2.) Producing designs or letters upon metallic surfaces in low relief, by first
painting the design in an acid resisting medium and then biting or etching the
unprotected portion by acid, as hereinbefore described.
Dated this 21st day or August 1994.
ROBERT E. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Agent for the Applicant.