A New or Improved Method of Decorating Wood.
Year: 1890

page_text: Date of Application, 1st Jan., 1890
Complete Specification Left, 24th June, 1890-Accepted, 26th July, 1890
PROVISIONAL SPECIFICATION.
A New or Improved Method of Decorating Wood.
We CARL HETTWIG, Manufacturer of Hollmannstrasse 33, Berlin and FRITZ
HECKNER, Engineer of Adolphstrasse 51, Braunschweig both in the Empire of
Germany do hereby declare the nature of this invention to be as follows
The object of this invention is a method or process by means of which permanent
designs or ornamentation may be drawn or niade upon wood in different shades of
brown or brownish colour.
The process depends mainly upon the canterizing of the surface in connection with
the actinism of light where said surface is not protected by a layer of material
impervious to the chemical substances employed.
We are aware that metals have heretofore been etched on surfaces not protected by
lacquer or the like but such lacquers are not suitable for wood since they are as a rule
opaque and do not generally colour.
The mechanical removal of them moreover injures the surface of the wood and
solution of them renders the surface of the wood dirty in appearance.
We use as an improved lacquer suitable for the purpose a concentrated solution of
caoutchouc in chloroform.
To prevent the cauterizing chemicals from "running" in the grain of the wood
the latter is saturated with alum as is done for preparing wood for painting.
The cauterizing chemical substances used are bichromate of the protoxide of copper
and pyrogallic acid.
The former is allowed to soak into the uncovered portions of the wood and before
it is perfectly dry a solution of pyrogallic acid is added, the surface being then exposed
to daylight so that the colour is developed.
The depth of shade is proportioned to the strength of the solutions which may
therefore vary from 4% solutions up to concentrated solutions: If the copper
solution predominates in strength a greenish hue is given if the pyrogallic acid
solution is the stronger a reddish tint results.
Dated this 1st day of January 1890.
HERBERT & Co.,
Agents to Applicants.
COMPLETE SPECIFICATION.
A New or Improved Method of Decorating Wood.
We, CARL HETTWIG, of Hollmannstrasse 33, Berlin, Manufacturer, and FRITZ
HECKNER, of Adolphstrasse, 51, Braunschweig, Engineer, both in the Empire of
Germany, 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 :-
The object of this invention is a method or process by means of which permanent
designs or ornamentation may be drawn or made upon wood in different shades of
brown or brownish colour.
The process depends mainly upon the cauterizing of the surface in connexion with
the actinism of light, where said surface is not protected by a layer of material
impervious to the chemical substances employed.
We are aware that designs have been cauterized on wood by hot irons and acids
also that metals have heretofore been etched on surfaces not protected by lacquer or
the like, but such lacquers are not suitable for wood since they are as a rule opaque
and do not generally colour. The mechanical removal of them moreover injures the
I Price Adl

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surface of the wood, and solution of them renders the surface of the wood dirty in
appearance.
We use as an improved lacquer suitable for the purpose a concentrated solution of
caoutchouc in chloroform.
To prevent the cauterizing chemicals from "running" in the grain of the wood the
latter is saturated with alum as is done for preparing wood for painting.
The cauterizing chemical substances used are bichromate of the protoxide of
copper and pyrogallic acid which are made up in separate aqueous solutions.
After the wood has been covered with the lacquer where desired and the lacquer is
set the bare places of the wood are painted over with the copper solution which is
allowed to soak into the uncovered portions of the wood and before it is perfectly
dry the same parts are painted over with the solution of pyrogallic acid the surface
being then exposed to day-light until the colour is developed.
The depth of shade is proportioned to the strength of the solutions which may
therefore vary from 4% solutions up to concentrated solutions.
If the copper
solution predominates in strength over the pyrogallic acid solution a greenish hue is
given, if the pyrogallic acid solution is stronger than the other a reddish tint results.
By suitable combination therefore of solutions of different strengths, great variation in
colour and shade may be given to the design.
The lacquer need not be subsequently removed.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The method of decorating wood consisting in the preparation of wood for local
chemical cauterizing or colouring by soaking in solution of alun and subsequently
coating parts to remain unaltered with solution of caoutchouc in chloroform,
subsequently treating said wood with solutions of bichromate of protoxyde of copper
and of pyrogallic acid or equivalent chemical matters adapted to tint or cauterize wood
on exposure to light, substantially as set forth.
Dated this 24th day of June 1890.
HERBERT & Co.,
18, Buckingham Street, Strand, W.C., London, Agents for Applicants.