IMPROVEMENTS IN PREPARING IRON TO BE COATED WITH TIN AND OTHER METALS
Year: 1837

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAM BOOKER, of Melin Griffith Works, in the County of Glamorgan,
Ironmaster, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fourth day of December, in the first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas William Booker, Her especial licence, full power, sole privilege and
authority, that I, the said Thomas William Booker, my exors, adññiors, and
assigns, and such others as I, the said Thomas William Booker, my exors,
admiors, or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term of years therein ex-
pressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention of
"IMPROVEMENTS IN PREPARING IRON TO BE COATED WITH TIN AND OTHER
METALS;" in which said Letters Patent is contained a proviso that I, the said
Thomas William Booker, shall cause a particular description of the nature
of my said Invention, and in what manner the same is to be performed,
to be enrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas William Booker, do hereby declare the nature of my Invention,
and the manner in which the same is to be performed, are particularly
described and ascertained in and by the following description thereof, reference
being had to the Drawing hereunto annexed, and to the figures and letters
marked thereon, that is to say:-
My Invention of Improvements in preparing Iron to be coated with Tin
and other Metals relates, First, to, that process of preparing iron called
pickling, and consists of a mode of heating the pickling liquor (diluted acid),
and in preparing iron plates to be coated with tin and other metals, in such
manner that the heat can be more uniformly kept than when heated by the
direct action of a fire, by which greater uniformity of production can be ensured.
Secondly, my Invention relates to a mode of submitting sheets of iron in such
manner to the action of the pickling liquor as to insure their being kept
separate, notwithstanding a number of plates are in the pickling trough at
one time, the sheets being put into the pickling trough one at a time. And
in order that my Invention may be most fully described and readily under-
stood, I will proceed fully to explain the process and apparatus employed by
me, and which I have found fully to answer. According to the present
practice of submitting sheets of iron to the pickling trough, the diluted acid is
either in a cold state or else in a heated state. When the pickle is in a cold
state the action is slow; and although the heating the liquor quickens the
action of the acidulated liquor on the metal, yet, there having been no effectual
means heretoforo resorted to for regulating the temperature, uniformity of
product cannot be obtained.
Now the object of the first part of my Invention is to introduco a medium
between the fire and the pickling liquor in such manner as to retain or obtain
the pickling liquor at any required degree of temperature, and in such manner
as not to be subject to the varying temperature which is consequent on
applying the heat of fuel direct to the pickling liquor, by which means I am
enabled to produce a much greater uniformity of result to the iron than when
the process of pickling is subject to the varying temperatures consequent on
nsing the naked fire to the liquor.
In respect to the second part of my Invention, I would state that, according
to the ordinary modo of submitting sheets of iron to the action of the pickle,
the usual mode is to take up a number of sheets at one time, and put them into
the pickle trough, and by agitating or moving them about to get the liquor or
pickle between the same, so as to operate on all the surfaces; but by such
means equality of effect of the pickle cannot be ensured, some surfaces and

page_text: parts of surfaces being too much acted on whilst other surfaces and parts of
surfaces are too little acted on by the pickle. Now the second part of my
Invention is so to arrange the pickle trough as to ensure each sheet of iron
being kept separate from its neighbouring sheets; and the plates are to bo
placed into the trough singly, in order to their being kept separate.
DESCRIPTION OF THE DRAWING.
I construct in the usual manner a fireplace A, with a door and ashpit
under it, and a side flue B, and a stack or chimney C, as shewn in the
Figure 1. Over the flue and fireplace A, B, I place an apparatus, which
consists of open or exterior vessel D, within which is placed another smaller or
interior vessel E of lead, Figure 2, which I find may be advantageously so
placed as to be within three inches of the bottom and three inches of the
three sides a, b, c, and nine inches from the fourth sido d. I fill the vacant
space F, F, F, F, between the exterior and the interior vessels with water,
the boiling point of which being, with the strength of pickle hereafter men-
tioned, what I have found most suitable for the purpose; and when working
with sheets of iron of the description most commonly used for making tin
plates, I prepare four grates of lead or wood or other material not prejudi-
cially acted on by the acid, with fourteen divisions in each, as represented in
Figure 3. I find it advantageous to have adjoining to the aforesaid exterior
vessel one, two, or more open vessels filled with water, as represented in
Figure 4. My apparatus thus complete and constructed is shewn in the
Figure 5. Within the interior vessel E the diluted acid is in the usual
manner to be placed, and to be heated by means of the fire in the fireplaces
through the conducting medium before described. When the pickle is thus
raised to the required temperature it is in a state to receive the iron plates,
and then the aforesaid grates, having either been previously filled with the
sheets of iron intended to be coated or without being so filled, are put into the
acid, and in the latter case the said grates are then filled with the said sheets
so to be prepared; and I find that the said sheets being put in so as to pass
through the acid separately or not in contact with each other, or as nearly
thereto as may be, admits of the action of the acid upon them in an improved
and more advantageous manner than has hitherto been adopted. When the
sheets thus immersed in the acid have been exposed thereto a sufficient
length of time to effect the purpose desired, which varies according to the
nature, description, and quality of the iron intended to be coated, they must
be taken out as rapidly as possible, and plunged immediately into the water in
the open vessels before described as adjoining the exterior vessels, and where

page_text: explained.
DESCRIPTION OF THE PROCESS.
Within the leaden vessel mix what is technically called the "pickle" which
consists of sulphuric acid (oil of vitriol) diluted with water to the strength
required for cleaning the iron plates. Begin with mixing it thus:-For
every gallon of water apply one pound (avoirdupois) of sulphuric acid to the
proof (by the graduated hydrometer) of 657; place in the vessel a sufficient
quantity of pickle to cover the iron plates when dropped perpendicularly or
edgeways into and between the pins or divisions. This done, light a fire in
the fireplace, and when the water begins to boil which is in the iron vessels
and flows round the leaden vessel, begin as rapidly as possible to drop the iron
plates singly and separately, one by one at a time, between the pins or
divisions, taking care that not more than two plates are at any time in and
between each pin or division, for it should be understood that the boiling point
of water, with the strength of pickle here given, is what I have found to be
best suited for preparing plates of iron of the description usually employed in
making tin plates; but these may be varied where the quality of the iron
varies, which the workmen will quickly understand after a little practice. The
four grates, with fourteen divisions in each, as before described, will afford
fifty-six divisions; within each of which divisions two plates may be dropped,
care being taken to drop every plate on its lateral edge, singly and separately.
The vessel will thus furnish room for one hundred and twelve plates at a time,
which an expert workman, assisted by a boy, will place there in two minutes;
and by the time the last plate is dropped into the last division, those of the
first division will be effectually cleaned and ready to be taken out of the pickle,
provided the plates have not previously undergone the process of annealing after
being cold rolled. If they have been so annealed they probably will require
to remain in the picklo a minute or a minute and a half longer, but this
will depend very much, first, on the strength or proof of the acid used in
preparing the pickle, and next, on the nature or quality of the iron plates,
particularly whether they are composed of iron manufactured with charcoal
or coke, and whether the iron, previous to its being rolled into sheets or plates,
has been subjected to the process of hammering. The precise length of time,

page_text: therefore, necessary for the plates to stand immersed in the pickle, must be
determined by the skill and discretion of the workman employed in cleaning
or applying the acid or pickle to them. His knowledge and experience of the
peculiar quality of the iron used will enable him to know of what strength his
pickle should be composed, and when to add acid and when to add water, and
to what height or degree to raise and regulate the temperature of the pickle
as the work. proceeds, also how many sheets or plates at one and the same
time should remain and be in the vessel exposed to the action of the pickle.
The moment the plates are effectually cleaned in the pickle, take them out
with a convenient tongs, or otherwise, and throw them into the cold water in
either of the vessels H, from which let them be taken as and when they are
wanted by the persons engaged in performing the next subsequent branch or
process of work.
Having thus explained the nature of the apparatus employed by me, I
would remark that, although I have mentioned water as the intermediate
means between the fire and the pickle, in order to the pickle not being directly
acted on by the fire, I would have it understood that I do not confine myself
thereto, as other matters may be employed, though I believe not with such
cheapness and facility as water. And further, the apparatus may be varied
without doparting from my Invention, provided the principle of action be
retained, and by which the temperature may be regulated and retained at the
required degree. And lastly, it is evident various means and apparatus may
be resorted to for keeping the sheets of iron separate when subjected to the
pickle. I do not therefore confine myself to the apparatus shewn, as the same
may be varied, and yet the plates kept separate one from the other, and
thereby may be obtained a means of ensuring more uniform action of the
pickle to all parts of each sheet of iron in the pickling trough at the same
time.
In witness whereof, I, the said Thomas William Booker, have hereunto
set my hand and seal, this Twenty-sixth day of May. One thousand.

page_text: AND BE IT REMEMBERED, that on the Twenty-sixth day of May, in
the year of our Lord 1888, the aforesaid Thomas William Booker camo
before our said Lady the Queen in Her Chancery, and acknowledged the Speci-
fication aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped!
according to the tenor of the Statute made for that purpose.
Inrolled the Second day of June, in the year of our Lord One thousand