AN IMPROVED PROCESS FOR_
Year: 1881

page_text: LETTERS PATENT to Adolph Guiensohn, of 40, Southampton Buildings, in the
County of Middlesex, for an Invention of AN IMPROVED PROCESS FOR_
T...
PROVISIONAL SPECIFICATION left by the said Adolph Gutensohn at the.
Office of the Commissioners of Patents on the 23rd April 1881.
ADOLPH GUTENSOHN, of 40, Southampton Buildings, in the County of Middlesex.
AN IMPROVED PROCESS FOR COATING WITH TIN THE SURFACE OF LEAD AND
OTHER METALS."
This Invention has for its object an improved process for coating the surface of
lead, alloys of lead, copper, or brass, or other metals with metallic tin. The lead or
other metal to which the tin is to be applied may be in the form of sheet, or tube,
or other flat or curved surface.
In order to put my Invention in operation I make a solution of chloride of tin,.
either saturated or of as great strength as conveniently possible, and free from
acid. I then, make a hot solution of pyrophosphate of soda of such strength that
crystals of the salt separate if the solution be allowed to cool, and I add the last
described solution to the solution of chloride of tin, phosphate of tin being
precipitated.
I collect the sediment thus precipitated and I dissolve it in an alkaline solution,
preferably caustic soda, to which about one per cent. of liquid ammonia- has been
added.
. :
The solution thus obtained is placed in a bath or vessel, and the lead or other
metal to be coated with tin is plunged into it, the deposit of the tin being effected.
by a current of electricity generated in any of the ordinary well known methods,
the positive pole from such generator being connected with fragments or sheets of
metallic tin suspended in the bath or vessel, whilst the negative pole is connected
with the lead or other metal which is to be coated.
The strength of the solution in the bath or vessel may be varied inversely
according to the strength of the electric current, the solution being more diluted as
the current of electricity is stronger.
•
In order that the coat of tin produced by the novel process described may be as
pure as possible, the chloride of tin used as first described should be entirely free
from iron.
:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Adolph Gutensohn in the Great Seal Patent Office on the
22nd October 1881.
ADOLPH GUTENSOHN, of 40, Southampton Buildings, in the County of Middlesex.
AN IMPROVED PROCESS FOR COATING WITH TIN THE SURFACE OF LEAD AND
OTHER METALS."
My present Invention has for its object an improved process for coating with
metallic tin the surface of lead, alloys of lead, copper, or brass, or other metals.
The lead or other metal to which the tin is to be applied may be in the form of
sheet, or tube, or other flat or curved surface.
In order to put my Invention in operation I make a solution of chloride of tin,
either saturated or of as great strength as conveniently possible, and free from
acid.
I then make a hot solution of pyrophosphate of soda of such strength that
crystals of the salt separate if the solution be allowed to cool, and I add the
last described solution to the solution of chloride of tin, phosphate of tin being
precipitated.
I collect the sediment of phosphate of tin thus precipitated, and I dissolve it in
an alkaline solution, preferably caustic soda, to which about one per cent. of liquid
ammonia has been added.
The solution thus obtained is placed in a bath or other suitable vessel, and the
lead or other metal to be coated with tin is plunged into, it or passed through it.
the deposit of the tin being effected by a current of electricity generated in any of
the ordinary well known methods, the positive pole from such generating apparatus
being connected with fregments or sheets of metallic tin suspended in the bath or
vessel already described, whilst the negative pole is connected with the lead or
other metal which is to be coated.
"
The strength of the solution in the bath or vessel may be varied inversely
according to the strength of the electric current, the solution being more diluted as
the current of electricity is stronger.
In order that the coat of tin produced by the novel process described may be as
pure as possible, the chloride of tin used as first described should be entirely free
from iron.
After the bath has been prepared as above described, I sometimes add to it a
small proportion of a solution of pure-chloride of tin, by which the solution is
made to contain a somewhat larger proportion of tin.
As the deposit of tin by means of electricity in the way described can be made
considerably thinner than tin applied to the surface of metal in the usual way by
rolling, considerable economy is effected in the cost of the tin, as well as in the
cost of repeatedly rolling in the ordinary way.
Having now described my Invention, and the manner in which it is to be
performed, I claim,—
The method of coating the surface of lead or other metal with metallic tin by
passing the metal to be coated through a bath of phosphate of tin prepared sub-
stantially as described, and dissolved in an alkaline solution, to which ammonia has
been added, a current of electricity being passed through the metal to be coated.
all substantially as and for the purpose described.
In witness whereof, I, the said Adolph Gutensohn, have hereunto set my
hand and seal, this 20th day of October, in the year of our Lord 1881.
ADOLPH GUTENSOHN. (L.S.)