Year: 1885

page_text: I, JAMES PRATT, of numbers 2. and 4. Pocock Street, Blackfriars Road, in the
County of Surrey, Glass Silverer and Gilder, do hereby declare the nature of this
invention, to be as follows:-
This invention relates to improvements in the process of gilding glass whereby
the desired effect is attained in a quicker, more regular and economical manner
than is the case by the means at present employed for that purpose.
The face of the. glass plate to be gilded is cleaned and a solution of chloride of
tin is poured over the same. The plate is then placed on an inclined bed, bench
or table, such as is described in the specification of Letters Patent granted to me
and dated 2nd February 1882, N° 515, which is heated and a mixture of a diluted
solution of gold in hydrochloric acid and nitric acid, with caustic soda and
glycerine or manite or a mixture of glycerine and manite is then poured over the
glass until the desired thickness of gold becomes deposited on it. The surface of
gold is then thoroughly washed, and, in some cases, a mixture of nitrate of silver
and ammonia with a certain amount of Rochelle Salts is poured on the gold and a
coating of silver becomes deposited, on the same. This method is at present well
known to the trade for silvering glass which has not been previously gilded. The
whole of the coating on the glass is then varnished and painted in the usual
manner.

page_text: C
Improvements in the Process of Gilding Glass.
I, JAMES PRATT, of numbers 2. and 4, Pocock Street, Blackfriars Road, in the
County of Surrey, Glass Silverer and Gilder, 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 said Invention relates to an improved process of gilding glass whereby the
desired effect is attained in a quicker, more regular and more economical manner
than is the case by the means hitherto employed for gilding glass.
According to my Invention the face of the glass to be gilded is thoroughly
cleansed in the usual way and a solution of Chloride of Tin (which may be prepared
as is usual for silvering glass) is poured over the glass which is then washed with
distilled water and placed on an inclined surface, it preferably being an inclined bed,
bench or table such as is described in the Specification of Letters Patent granted to
me and dated 2nd February 1882 N° 515. which table is heated preferably by steam
and a mixture of a dilute solution of chloride of gold that is a solution of gold
in Aqua Regia (hydrochloric acid and nitric acid) with pure caustic soda and
glycerine with or without manite is poured over the glass until the desired
thickness of gold becomes deposited on it; the gold coating is then thoroughly
washed with distilled water.
The aforesaid mixture I find to answer well if it be prepared in the following
way and with the following proportions of the ingredients.
I dilute the ordinary solution of chloride of gold by adding to every 3 parts
thereof by weight 40 parts by weight of distilled water. I then prepare a
solution of caustic soda by dissolving 1 part by weight of pure caustic soda in
20 parts by weight of distilled water and I also prepare a solution of glycerine
and distilled water taking equal parts by weight of each and to this I prefer to
add a few drops of manite as I find that it expedites the deposit of the gold on
the glass.
The soda solution is first added to the glycerine solution and then just before
use they are added to the chloride of gold solution.
The following is the best way with which I am acquainted for carrying out the
process.
I cleanse the glass and treat it with the Chloride of Tin solution in the same
manner as is at present practised in treating glass preparatory to silvering it with
a solution of nitrate of silver. I then thoroughly wash the glass with distilled
water by pouring it thereover and I remove the glass to the inclined heated table
and maintain the heat at about 150° to 200° Fahrenheit and I then pour over the
glass the gilding solution prepared as hereinbefore described. The glass should be
supported upon a layer of india rubber cloth so that there is as little waste of the
gilding solution as possible it being received as it flows from the table in any
suitable receptacle from which it can be taken for reuse. The pouring is continued
until the metallic film appears over the whole surface of the glass which will
usually be in about 10 minutes and then the gilded glass is removed and again
washed with distilled water.

page_text: I then cover the gold with silver by pouring over the gilded surface a mixture
of nitrate of silver and ammonia with a certain amount of Rochelle salts as is well
known and practised in silvering glass.
The gilding and silvering of the glass having been effected the metallic coating
on the glass can be varnished and painted in the usual manner to protect it from
injury.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
First. In the manufacture of gilded glass first treating the cleaned glass with a
solution of Chloride of Tin and then pouring over the glass whilst supported upon
an inclined surface and heated a gilding solution, substantially as hereinbefore
described.
Secondly. In the manufacture of gilded glass pouring over the glass after it
has been properly cleaned and prepared a gilding solution whilst the glass is
supported upon an inclined surface and heated, substantially as hereinbefore
described.
Thirdly. In the manufacture of gilded glass pouring over the surface of the glass
properly cleaned and prepared a gilding solution whilst the glass is supported upon
an inclined surface and heated and then applying to the coating of gold a silver
backing, substantially as hereinbefore described.
And Fourthly. The manufacture of gilded glass by treating the cleaned glass
with chloride of tin solution and then pouring over the surface of the glass a
gilding solution whilst the glass is supported upon an inclined surface and heated
and applying to the coating of gold a silver backing, substantially as hereinbefore
described.
Date LLLL
T.... 1000