IMPROVEMENTS IN MAKING GIPSUM CASTS AND FORMS WASHABLE WITHOUT INJURY TO THEIR APPEARANCE
Year: 1878

page_text: LETTERS PATENT to Friedrich von Dechend, of Bonn, in the Empire of
•
Germany, for the Invention of "IMPROVEMENTS IN MAKING GIPSUM CASTS
AND FORMS WASHABLE WITHOUT INJURY TO THEIR APPEARANCE."
Scaled the 10th December 1878 and dated the 20th June 1878
PROVISIONAL SPECIFICATION left by the said Friedrich von Dechend at the
Office of the Commissioners of Patents on the 20th June 1878.
FRIEDRICH VON DECHEND, of Bonn, in the Empire of Germany. "IMPROVE-
MENTS IN MAKING GIPSUM CASTS AND FORMS WASHABLE WITHOUT INJURY TO
THEIR APPEARANCE."
The Invention comprises the rendering of plates, casts, and ornaments impervious
to wet by the application of chemicals.
The process is divided into two distinct operations. One consists in the appli-
cation of a solution of borax, alum, or other suitable substance, having in view the
hardening of the plaster; and the finishing operation consists in the application of
insoluble precipitates, by which the minutest pores are filled up, and the surface
rendered waterproof.
The one operation need not necessarily precede the other, nor do I limit myself
to the use of any particular chemicals to attain my object, salts of barium, calciuni,
and strontium being suitable for obtaining insoluble precipitates without forming
spots.
One method of performing the same may be as follows:-A hot saturated solution
or borax is spread with a brush over the divers plaster objects to be treated any
requisite number of times; next hydrochlorate of barytes likewise, in the form of a
hot solution, is laid on with a brush and repeated if required; then soap solution is
likewise applied hot, and is greedily absorbed by the porous plaster, any excess
being removed with hot water.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich von Dechend in the Great Scal Patent Office on the 17th
December 1878.
FRIEDRICH VON DECHEND, of Bonn, in the Empire of Germany.
"MAKING
GIPSUM CASTS AND FORMS WASHABLE WITHOUT INJURY TO THEIR APPEARANCE."
The Invention comprises the rendering of plaster casts and ornaments impervious
to wet by the application of chemicals.
The process is divided into two distinct operations. One consists in the appli-
cation of a solution of borax, alum, or other suitable substance, having in view the
hardening of the plaster; and the finishing operation consists in the application of
insoluble precipitates, by which the minutest pores are filled up and the surface
rendered waterproof.
The one operation need not necessarily precede the other, nor do I limit myself
to the use of any particular chemicals to attain my object, salts of barium, calcium,
and strontium being suitable for obtaining insoluble precipitates without forming
spots.
One method of performing the same may be as follows:-A hot saturated solution
of borax is spread with a brush over the divers plaster objects to be treated any
requisite number of times; next hydrochlorate of barytes likewise, in the form of a
hot solution, is laid on with a brush and repeated if required; then soap solution is
likewise applied hot, and is greedily absorbed by the porous plaster, any excess
being removed with hot water.
In witness whereof, I, the said Friedrich von Dechend, have hereunto set my
hand and seal, this Sixteenth day of December, A.D. 1878.
תזו ח"ח
ידזםזמזמ