Improvements in the Process of Tinning Iron and Steel Plates.
Year: 1892

page_text: Date of Application, 22nd Nov., 1892-Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
Improvements in the Process of Tinning Iron and Steel Plates.
I, EDWIN NORTON, residing in Maywood, in the County of Cook, in the State
of Illinois, United States of America Manufacturer, do hereby declare the nature
of my 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 improvements in the process of tinning iron and steel
plates.
The object of my invention is to produce from the black iron or steel sheets,
finely finished tin plate, without the use of what is known in the art as "brushing;'
that is to say the brushing of each sheet on both sides by hand with a hempen
brush to remove the granulated superfluous tin left upon the surface after soaking
in the tin bath.
Where palm oil, tallow, or tallow and resin, or similar grease or oil fluxes are
used as a preliminary coating for the sheets before dipping the same into the tinning
or soaking bath, it has always been necessary to perform the brushing operation
mentioned before dipping the sheet into the finishing bath of clean tin preparatory
to passing it between the finishing rolls.
To overcome this item of cost and labor with its attendant loss of oxidation of
the tin in brushing, other fluxes than those above mentioned have been sometimes
employed; but these other fluxes have as a base muriatic acid, which renders them
destructive to the iron or steel, often causing great loss by pin holes, and such fluxes
are always unpleasant to use and even dangerous to workmen.
I have discovered that stearic acid applied to the sheet will cause the tin to
flow thin and smooth, and produce a better finish than the muriatic acid flux
without any of the evils of the latter. And this is particularly the case in the
making of what is known as "coke finish" tin plates, where only two to two and
one-half pounds of tin are used to the box of plates. With the stearic acid flux a
bright, silvery, smooth finish may be obtained upon these plates without the
expense of brushing, a thing which cannot be done by use of the grease fluxes
formerly employed, and this also without any of the injurious effects similar to
those which result from the employment of muriatic acid as a flux.
In practising my invention the black plates are first "white pickled" in any of
the usual ways, an operation so familiar as to require no special description, the
sheets are next coated with the stearic acid preferably by dipping them into a
molten bath of the same; the sheets are then dipped into the molten bath of tin
and finished in the usual way.
The stearic acid, besides being productive of the advantages above mentioned,
is clean and pleasant to handle, is very fluid when melted and consequently covers
easily, and as a material costs about the same as palm oil flux so extensively used.
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 :-
The process of making tin plate which consists of the following steps: first white

page_text: pickling the sheets; second coating the same with melted stearic acid; third
immersing the same in melted tin and finishing, substantially as specified.
Chicago. Illinois USA
October 26th 1000
Witnesses:
H. M. MUNDAY.
EMMA HACK.
EDWIN NORTON.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.