IMPROVEMENTS IN THE MANUFACTURE OF VARNISH, AND IN TREATING OILS, ALSO IN THE APPLICATION OF PRODUCTS OBTAINED THEREFROM
Year: 1860

page_text: LETTERS PATENT to Frederick Walton, of Haughton Dale, Denton, near
Manchester, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF VARNISH, AND IN TREATING OILS, ALSO IN THE APPLICATION OF PRODUCTS
OBTAINED THEREFROM."
Sealed the 3rd July-1860, and dated the 27th January 1860.
PROVISIONAL SPECIFICATION left by the said Frederick Walton at the
Office of the Commissioners of Patents, with his Petition, on the 27th
January 1860.
I, FREDERICK WALTON, of Haughton Dale, Denton, near Manchester, do
hereby declare the nature of the Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF VARNISH, AND IN TREATING OILS, ALSO IN THE APPLICATION OF
PRODUCTS OBTAINED THEREFROM," to be as follows:-
This Invention has for its object improvements in the manufacture of
varnish, and in treating oils, also in the application of products obtained there-
from. It is well known that when drying oils are exposed to the action of air,
or are oxydized, they become converted into bodies of a semi-resinous nature.
Now, according to my Invention, I convert drying oils into semi-resinous
bodies, and dissolve these latter in volatile solvents. The preparation thus
obtained dries rapidly like spirit varnishes, and leaves a flexible and tough
film, similar to that produced by the application of oil varnishes, which take a
long time to dry or harden. Drying oils may be converted into semi-resinous
matters by laying a thin film of the oil on a surface of considerable extent,

page_text: and exposing the film to currents of warm air till the change is produced.
The semi-resinous matter may be removed from the surface when it is desired
to produce a varnish by washing the surface in the solvent, or it may be
separated by scraping the surface; or if the process be stopped before the
change is complete, it may be separated by placing many layers of the material
(usually paper or fabric) on which the oil was laid one over the other, and
submitting the pile to a heavy pressure. In order to render the change of
the oil when exposed in thin films as above mentioned more rapid, I prepare
the oil by driving it by means of a considerable pressure through jets or
orifices in very fine streams, which are caused to pass through a case constantly
supplied with warm air. This process is also applicable in preparing drying
oils for other uses, for which it is desirable that the oil should dry or harden
with rapidity. The semi-resinous bodies obtained as above described from
drying oils may be rendered plastic by heat, and in this state may be applied
to fabrics and surfaces either alone or mixed with other substances, by means
of rollers or pressing surfaces; or the material may, particularly when mixed
with fibre, be rolled or pressed out into sheets.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Walton in the Great Seal Patent Office on the
27th July 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
WALTON, of Haughton Dale, Denton, near Manchester, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of January, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Frederick Walton, Her special licence that I, the said Frederick Walton,
my executors, administrators, and assigns, or such others as I, the said Frederick
Walton, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF VARNISH, AND IN TREATING OILS, ALSO IN THE APPLICATION OF
PRODUCTS OBTAINED THEREFROM," upon the condition (amongst others) that I,
the said Frederick Walton, my executors or administrators, by an instrument

page_text: in writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and in.
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frederick Walton, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
thereof, that is to say :-
This Invention has for its object improvements in the manufacture of
varnish, and in treating oils, also in the application of products obtained
therefrom. It is well known that when drying oils are exposed to the action
of air, or are oxidized, they become converted into bodies of a semi-resinous
nature. Now, according to my Invention, I convert drying oils into semi-
resinous bodies, and dissolve these latter in volatile solvents. The preparation
thus obtained dries rapidly like spirit varnishes, and leaves a flexible and tough
film similar to that produced by the application of oil varnishes, which take a
long time to dry or harden. Drying oils may be converted into semi-resinous
matters by laying a thin film of the oil on a surface of considerable extent,
and exposing the film to currents of warm air till the change is produced.
The semi-resinous matter may be removed from the surface when it is desired
to produce a varnish by washing the surface in the solvent; or it may be
separated by scraping the surface; or if the process be stopped before the
change is complete, it may be separated by placing many layers of the material
(usually paper or fabric) on which the oil was laid one over the other, and
submitting the pile to a heavy pressure. In order to render the change
of the oil when exposed in thin films as above mentioned more rapid, I
prepare the oil by driving it by means of a considerable pressure through jets
or orifices in very fine streams, which are caused to pass through a case
constantly supplied with warm air. This process is also applicable in preparing
drying oils for other uses, for which it is desirable that the oil should dry or
harden with rapidity. The semi-resinous bodies obtained as above described
from drying oils may be rendered plastic by heat, and, in this state may be
applied to fabrics and surfaces either alone or mixed with other substances,
by means of rollers or pressing surfaces; or the material may, particularly
when mixed with fibre, be rolled or pressed out into sheets.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the manner in which I
prefer to operate.

page_text: In order to obtain a semi-resinous body or to increase the drying properties
of an oil, I proceed as follows:-I take linseed oil perfectly clear and bright,
and I mix therewith a suitable drier, preferring to employ from 5 to 10 per
cent. of acetate of lead; this mixture I pass through the machine shown in
the annexed Drawing:
Figure 1 is a front view; Figure 2, a plan; and Figure 3; a vertical section
of the machine. a is a pipe leading from a force pump, by which the oil is
forced into the vessel b; at the bottom of this reservoir is a grating c, the per-
forations in which are very fine, say th of an inch or less in diameter; the
grating is supported on a suitable gridiron frame beneath it. The oil forced
through the perforations falls in a fine shower throgh the column d, and as it
falls it comes in contact with a current of air forced in at e, by a fan. The two
sides of the column are enclosed with glass, in order that light may enter the
column, as it tends to bleach the oil. f and fare sheets of perforated zinc ;
through the sheet the air enters the column, and through the sheet f' it escapes
from it; these perforated sheets diffuse the air entering at e, and prevent the
fine streams of oil from being blown out of the column. The current of air that
passes through the apparatus need not be very strong, as all that is required
is constantly to change the air in the column. The front of the apparatus may
either be left open, as is shown, or a casing may be employed to conduct the
air which has been brought in contact with the oil into a flue. The oil descends
into a cistern g, under the bottom of which is a steam space h, by which the
oil under treatment is kept at a temperature between 212° and 550° Fahren-
heit. When the higher temperatures, however, are employed, it is convenient
to substitute for steam, as a heating medium, a bath of a fusible metal, such
as tin or an alloy of tin and lead, the higher the temperature the more rapid
will the process become. i is a pipe communicating with the oil pump for
taking the oil from the cistern g, and returning it to the top reservoir b; thus
the same oil is kept circulating through the machine until it is judged to be
sufficiently vicid for the purpose for which it is required. At the top of the
reservoir b is a small cylinder j, in which a piston k works; is a lever in con-
nection therewith, weighted to the pressure which it is desired to maintain in
the vessel b. From the lever 7 a rod m descends, and is connected with a cock
in the pipe i in such a manner that when the piston k rises from excess of
pressure, the communication between the oil pump and the cistern g is
cut off.
Oil treated as above described, when it has thickened sufficiently, is suitable
to be used by painters and others in place of boiled oil, and it will be of a
better colour.

page_text: In some cases, particularly when it is desirable to work with as little lead as
possible, I boil the oil in the usual manner of boiling linseed oil, before sub-
mitting it to the action of air, as above described. I do not add any acetate
of lead after the boiling operation, and during the subsequent process I do not
raise the temperature of the oil to so high a degree as when working with un-
boiled oil; 212° Fahrenheit is sufficient. The product obtained from boiled
oil will be more highly colored than that obtained by the use of unboiled oil.
If the process is to be carried on to a sufficient extent to obtain a semi-
resinous body, the process should not be carried so far in the machine above
described as materially to reduce the fluidity of the oil; the change being
afterwards completed by spreading the oil in a thin film on an extended surface.
For this purpose I run out the oil into tanks, which I make cubical, say,
three feet every way; each tank is furnished with an open frame of metal,
which will just fit within it, and can be lifted in and out as required. The
frame consists of four uprights, equal in height to the depth of the tank, and
suitably framed together, so that when the frame is in its place they stand
in the four corners or angles formed by the meeting of the sides. In each
corner post a groove is formed to serve as a guide for the ends of rods,
which are employed as is herein-after explained.
In order to distend in this frame a considerable length of fabric, one end
of the fabric is attached to a bar, which is then dropped into the guides in
the two uprights at one end of the frame. The fabric is then taken to the
other end of the frame, and another bar is dropped in over it in the guides
in the uprights at the other end of the frame; it is then taken back to the
point where it was first made fast, and a third bar is dropped in, and so on
till the frame is full. If, as I prefer, the bars are made half-an-inch thick,
the frame will take in 72 yards of a yard wide fabric, cach layer of which
is kept distended, and out of contact with the layers above and below it.
The fabric which I prefer to employ is a strong cotton cloth, or a stout
paper may be used.
The frames, when thus covered, are dipped into the oil tanks, then drawn
out again, and suspended above them, and while thus suspended, they are
submitted to a current of air. It is a convenient arrangement to place a
series of oil tanks in a row, side by side, in a suitable chamber, and to mount
an axis about five or six feet over the row of tanks. These axes have drums
mounted on them, and the fabric frames are connected with these drums by
chains, so that by turning' the axis the whole of the frames suspended from it
can be raised from or lowered into their tanks, as may be required. Air is
forced into the chamber at one end by a fan, and is allowed to escape at the

page_text: touched.
other end. It is preferred, in order to keep the oil fluid, to heat the oil tanks
by means of steam. In conducting the process when a number of frames
have been filled with fabric, and suspended over their oil tanks, as above
described, they are, by turning the axis from which they are suspended, all
simultaneously lowered into the oil tanks, and are then immediately lifted to
their original positions. By this dipping, the whole surface of fabric is
covered with oil, and any superfluous oil which may be taken up runs back
into the oil tanks. The frames aro kept suspended in the current of air,
by preference, until the film of oil is dry, and no longer feels tacky when
This will take about twenty-four hours, but the, time will vary
greatly according to the state of the weather. The frames, when dry, are
redipped, and the process is thus continued until a thickness of dry oil, about
th of an inch in thickness, is accumulated on the surfaces of the fabrics.
It will take some weeks to obtain a sufficient thickness. I would remark
that it is not essential that the oil should be prepared by the use of the
machine shown in the Drawing before spreading it in films on a surface, as
above described; I prefer, however, that this should be done, as it tends to
expedite the process. The frames, when a sufficient thickness of dry oil has
been accumulated, are removed, and the fabric stripped from them. If woven
fabric has been employed in order to separate the dry oil or semi-resinous
matter from the fabric, the same is passed at a slow speed, say, about two
yards per minute, between two plates heated with high-pressure steam, and
having only sufficient space between them to allow of the fabric being passed
through conveniently. Just beyond the plates are two rollers, the distance
between which is adjustable by screws, or otherwise. The end of a length of
coated fabric passing between the plates is entered between the rollers, and
the semi-resinous matter having been scraped off by hand from a few inches
of the fabric, the rollers are caused tightly to nip the end so cleaned. The
rollers are then set in motion, and by their pressure they separate the coating
from the fabric, the former being constantly pressed back, whilst the fabric
passes on between them, and is ready again to be placed on the frames.
The semi-resinous matter separated from the fabric is differently treated
according to the purpose to which it is to be applied. If it is to be used for
coating fabrics to waterproof the same, the semi-resinous matter is passed
several times between crushing rollers heated by steam, to break it down and
reduce it to a uniform plastic mass. I prefer that one of these rollers should
be driven considerably faster than the other, in order that they may have a
guiding as well as a crushing action on the material as it passes between
them. During this operation I prefer to work in with it powdered gum lac,

page_text: either shellac, seed lac, or button lac. The quantity of this gum to be
employed varies according as it is desired that the coated fabric should be
more or less flexible, and the composition more or less hard.
If great
flexibility be required, I add but ten per cent. of gum shellac, whereas if a
hard face is desired, I add as much as fifty per cent. When the mixing is
complete, the composition is spread on the fabric by rollers, as is sometimes
practised with india-rubber and gutta percha. In place of completing the
kneading of the material by means of rollers, it may, after being passed two
or three times between the rollers to crush it completely, be further worked
in a masticator, such as is used in the working of india-rubber and gutta
percha. In a similar manner I prepare a composition suitable for rolling
out into sheets without fabric, and which sheets may be applied to various
useful purposes. In this case, however, I prefer also to mix in flocks in the
masticator, or by means of the rollers, to increase the toughness of the sheet.
The composition may be rolled into sheets, as is practised when working
gutta percha, and it may in a similar manner be moulded by dies and pressure.
It is preferred that the dies should be heated. Articles so produced may
be rendered very hard by drying them thoroughly in a cool oven.
If it be desired to produce a varnish, the semi-resinous body, when it is
removed from the fabric, is passed between very accurately formed and hard
rollers, known as "chilled" rolls, and is by them crushed into a sheet about
the thickness of tissue paper. To this alcohol or wood spirit is added in the
proportion of 6 gallons to 9 pounds of semi-resinous material, and the mixture
is placed in a still in which a shaft is mounted. It descends through a
stuffing-box at the top, and has radial arms mounted on it to stir the mixture,
and arms are mounted on the sides of the still itself, between which the arms
on the shaft pass. Heat is applied to the mixture until the semi-resinous
material is completely dissolved. A portion of the solvent distils over, and
may be at once returned to the still, or may be employed in a subsequent
operation. By distilling off more or less solvent, the thickness of the varnish
may be regulated as is required; or, the varnish may be made by using
chilled rollers, and working the semi-resinous material along with the solvent
until a paste is produced, which may then be completed by heat in the still.
For many uses this varnish will be improved by adding to it a solution of
shellac or other resins soluble in the same solvent as the semi-resinous body
which tends to harden the varnish.
When the semi-resinous material is to be employed in the manufacture of
varnish, it is convenient in some cases to expose the films of oil to the action
of the air on sheets of paper, in place of on a woven fabric of cotton, which I
°

page_text: usuany
proy:
ULLES Case
paper
by rollers, as above described, but I place the paper, with its coating of semi-
resinous matter, in the solvent, and break up the paper, which I afterwards
separate by filtration.
In witness whereof, I, the said Frederick Walton, have hereunto set
my hand and seal, this Twenty-third day of July, in the year of our
Lord One thousand eight hundred and sixty.
FREDERICK WALTON. (L.S.)