IMPROVEMENTS IN AIR AND WATERPROOF COATINGS, AND IN THEIR APPLICATION."
Year: 1856

page_text: LETTERS PATENT to William Clark, of 58, Chancery Lane, in the County
of Middlesex, Engineer, for the Invention of IMPROVEMENTS IN AIR AND
WATERPROOF COATINGS, AND IN THEIR APPLICATION."-A communication.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
6th December, 1856.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer, do hereby declare the nature of the said Invention for " IMPROVE-
MENTS IN AIR AND WATERPROOFS COATINGS AND IN THEIR APPLICATIONS," being a
communication to me by a foreigner residing abroad, to be as follows:-
This Invention is relative to the fabrication of coatings of glutinous mate-
rials, employed particularly in dyeing and painting, in the preservation of
moulded plasters, porous stones, and organic pervious alterable substances. It
is a kind of artificial leather, composed of gelatine and tannin. In preparing
and applying these coatings, I imprint or coat the objects to be treated with
gelatine, isinglass, (or fish glue) and glue, and other glutinous matters, and
after drying, soak them in a solution of tannin, or of matters containing tanuic
acid, such as nutgall, sumac, bolbah, or oak bark. By this immersion the
materials are coated and penetrated, according as theyare more or less porous,
[Price S.

page_text: with an artificial leather, which permits them to retain their elasticity.renders
them of uniform consistency, impervious to air and water, and imparts a
facility for taking and fixing colors, and, lastly, preserves all organic matters
from decay. With these coatings I render papers and all kinds of stuffs
impervious to air and water. These coatings are also adapted as a substitute
for gelatine in dyeing and gilding,and in the manufacture of "papier mache."
I fix and render size colors insoluble, by covering them with a thin layer of
gelatine and silicate of potash or silicate of soda (these two last being employed
instead of the tannic acid). In dyeing, the gelatine (employed for fixing the
mordant oxides) can be replaced by albumine or caseine.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the 26th
June 1857.
TO ALL TO WHOM THESE PRESENTS' SHALL COME, I, WILLIAM
CLARK, of 53. Chancery Lane, in the County of Middlesex, Engineer, send
greeting.
WHEREAS Her Most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of December, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did. for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, 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 AIR AND
WATERPROOF COATINGS, AND IN THEIR APPLICATION," a communication, upon
the condition (amongst others) that I, the said William Clark, my executors
or administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly 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 William Clark, do hereby declare
the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following
statement (that is to say)
--
This Invention is relative to the fabrication of coatings of glutinous mate-
ials, employed particularly in dyeing and painting, in the preservation of
moulded plasters, porous stones,and organic pervious alterable substances. It
is a kind of artificial leather, composed of gelatine and tannin. In preparing
and applying these coatings, I imprint or coat the objects to be treated with
gelatine, isinglass (or fish glue), glue, or other glutinous matters, and after
drying, soak them in a solution of tannin, or of matters containing tannicacid,
such as nutgall,sumach, boblah,or oak bark. By this immersion the materials
are coated and penetrated, according as they are more or less porous, with an
artificial leather, which permits them to retain their elasticity, and renders
them of uniform consistency, impervious to air and water, and imparts a
facility for taking and fixing colors, and, lastly, preserves all organic matters
from decay. With these coatings I render papers and all kinds of fabrics or
stuffs impervious to air and water. These coatings are also adapted as a
substitute for gelatine in dyeing and gilding, and in the manufacture of
papièr maché." I fix and render size colours insoluble, by covering them
with a thin layer of gelatine and silicate of potash or silicate of soda (these
two last being employed instead of the tannic acid). In dyeing, the gelatine
(employed for fixing the mordant oxides) can be replaced by albumen or
caseine.
66
In the preparation or dressing of cotton or other goods or fabrics, the great
loss of starch, gelatine,gum,&c.,and also of alkaline, silicate,renders it necessary
again to apply the preparation or dressing after every washing, and the advan-
tage with which the application of a permanent preparation or dressing maybe
used for industrial purposes, forming in a manner one body with the
pre-
pared substance, may be readily conceived.
Some such advantages have been obtained in the preparation or dressing
stuff goods by using solutions of india-rubber, but this substance is very
expensive, and its solvent gives a disagreeable and lasting odour to the
materials prepared.
With respect to the fixing of colours in dyeing, among other processes of
animalizing fabrics, I have indicated the penetrating them with gelatine,
which is rendered insoluble by combining it with tannin.
Of this same chemical action advantage is taken to impart to the fabrios a
preparation or coating uniting the conditions of incorruptibility (not subject
o decay) with that of not detaching itself in washing, or even by a slight
application of soap,and of giving the stuffs or fabrics their original consistency

page_text: and elasticity after this washing, by ironing them only, or by mangling or
calendering them in a warm state.
This preparation or coating can be applied by successive immersions of the
stuffs or fabrics, to be prepared, in tepid or warm solutions of gelatine and
tannin, the materials being wrung and allowed to dry after each immersion.
In these successive applications care should be taken which agent is first
used. The operations for preparing the fabrics should be commenced by
immersing the fabrics in a bath of gelatine, and be terminated by their
immersion in a bath of tannin, for this reason, that the tannate of gelatine or
artificial leather that is obtained is slightly soluble in the gelatinous bath.
Besides adapting the preparation or coating above described to cotton, flax,
silk, and woollen fabrics or stuffs by this method, success has been obtained in
preparing a perfectly impervious and very solid felt,composed of thick wollen
fabrics, by felting these fabrics, strongly impregnated, with artificial leather.
The impermeability is still further secured by the addition of fatty bodies in
the felting process. When well prepared, fabrics of thin cotton, flax,cr silk
are rendered transparent by linseed oil; they will serve for the manufacture of
window and other blinds. The gelatine intended for these various operations
consists of glue, bone, gelatine, dust, glutinous matter.&c.,&c., according to
the nature of the fabrics. The tannin is made of all tanning substances,
pure tannin, decoction of nutgall, decoction of sumach, of boblah, and also
of oak bark.
This improved method of preparing fabrics applies either to stuffs or
fabrics in the piece, or to made up articles; it is particularly applicable to
cordage and sails of ships.
Printing or Impressing. In the same manner as in the application of
soluble silicates for printing or impressing with mineral colours, I also
resort to the combination of tannin and gelatine for fixing all insoluble
colours on fabrics, which are ordinarily fixed by means of albumen.
The imprinting or impressing is effected by the ordinary processes with a
solution of gelatine, in which the coloring matters are diluted, as ultramarine
blue, sulphuret of cadmium, lakes, and all other colors not acted on by a
solution of tannin. The printing should be conducted in a heated workshop,
in order to prevent the gelatine from coagulating; the printed fabric is then
dried and put into a warm bath of nutgall, sumac, boblah, or any other dry
tanning matter. This method of fixing colors is very suitable for and works
well with the operations of dyeing. Thus many metallic solutions thickened
by means of gelatine, and fixed by the tannin,give very standing or permanent
impressions by a subsequent immersion in a bath of taunin.
Acetate of

page_text: alumina diluted in gelatine and fixed by the tannin, gives, when mixed with
madder, very rich red colors, which are more solid than those obtained by the
ordinary processes of printing or impressing. The same results are obtained
with other colors not changeable by tannin.
The dyeing or impressing of greys and blacks is effected by passing the
fabrics printed or impressed with artificial leather into baths holding iron in
solution.
With all colours impressed with tannate of gelatine, the ground is easily
whitened by chlorine, which does not dissolve the gelatine. It is certain that
calico printers will derive great advantage from the use of tannate of gelatine
in innumerable circumstances; gelatine, either as for the thickening of the
mordants, or as a recipient of the colors to be fixed, being destined to occupy
an important place in dyeing and printing operations.
Coating Paintings.-One of the most important applications of my coating
of artificial leather consists in using it for fixing colors in distemper.
It is known that colors applied with size or gelatine are easily removed by
a washing in water, which does not permit their use for external purposes.
According to my Invention, it is sufficient to wet the colors thus applied by
means of a brush or sponge, or by watering them with a solution of tannin
obtained from nutgall, sumach, or any other tanning matter, in order to prevent
the removal of the color so applied either by cold or hot water, either
immediately after its application or after it isdry. This solution of taanin may
be applied in one or more coats or layers, but it is better to apply it in several
coats of a weak solution in succession, to prevent different shades of colour
resulting from the rapid absorption of the tannin, especially when painting on
mortar or plaster. These shades of color can be more surely prevented by
covering the painted part first with a coating of gelatinous solution, more or less
weakened, and applying the tannin after complete desiccation. This method
of operation produces a very durable varnished paint. Decoctions made with
one part of nutgall to ten parts of water are in most cases sufficiently concen-
trated; but it is better to keep below this proportion, and apply it several
times. By the application of these coatings the color is fixed and retained on
wood, stone, metals, or other bodies with great tenacity; it never peels off, on
account of the elastic properties of the leathery cement. Very old paintings
in distemper can be fixed as well as new paintings, but become slightly
browned, especially where concentrated solutions are used, unless the solutions
are composed of pure tannin. For coarse paintings I use sumach, which gives
a greenish hue to the white ground, but this tint is extremely slight when only
the necessary proportions of the tanning matter are used. The infusion of oak

page_text: bark produces tannates of less consistency, and having more color, and is
only applicable for coarse paintings.
When I apply colours diluted in solutions of albumen or of milk, I likewise
fix them by means of the tannin, but albumen and milk are in general much
too high priced. In the operations above-described for fixing distemper
colors, as well as in my application of silicates for paintings, it is particularly
desired to include under this Patent the application of artificial sulphate of
baryta, and I will also add for the tanned paintings the application of sulphate
of strontian, and even fine plaster, which I dilute in gelatinous solutions to
obtain a ground, without excluding the chalk used in common painting. The
artificial sulphate of baryta in particular furnishes an admirable coating or
painting material for walls, ceilings, &c.
When the successive coats, three for example, have been applied, the color
is polished by a pumicing, and the work terminated by applying the taunin in
coats of a very weak solution, if a more glossy surface is desired. Previous
to the application of the tannin, the surface to be hardened is covered with a
gelatinous solution. By employing a tanning matter slightly colored, magni-
ficent white grounds are obtained, which are as polished as a mirror.
I have no doubt that the substitution of the artificial sulphate of baryta for
zinc white and white lead or ceruse in fine paintings will soon become general
for painting the panelling of drawing-rooms, and that it will also be applie!
for whitening the ceilings of the most humble dwellings.
All painting matters, according to this Invention, are infinitely better when
the artificial sulphate of baryta is used as a base than when using zinc white
or white lead; the baryta white mixed with size covers well and presents
a whiter, finer, and smoother colour.
Various applications of the coating before-described. In additiontotheuseof
tannate of gelatine or artificial leather for the purposes of preparing or dressing
stuffs or fabrics printed and painted, herein-before described, other very varied
and not less important applications have been found. For instance, on moulded
plaster or porous stones I apply an impermeable elastic coating not liable to
decomposition, by penetrating these bodies by means of cold immersion, or,
still better, by a warm immersion, or sprinkling, &c, first with a gelatinous
solution, and after desiccation, with a solution of tannin produced from one
or other of the various sources already indicated, oak bark included.
By the application of the same processes I render fishing nets, cordage,
sails, and also the wood of ships not liable to decay. The same processes
likewise apply to railway sleepers, and all organic materials subject to decay.
In the latter cases, in order to the better insure the preservation, I add to

page_text: the gelatinous solution a little arsenious acid or, better still, arsenite of potash
which is decomposed when the tannin is applied.
Lastly, paper pulp penetrated with gelatine will give, by means of pressure,
monldings and objects of ornament, which are consolidated by immersion in
tanning solutions.
After the application of the tannin to paper pulp treated with gelatine, a
very clear impression is obtained by pressing the objects to be moulded, while
yet slightly wet, in heated moulds.
Having described the nature of my Invention, and the manner in which the
same may be performed, I wish it to be understood that I claim as the
Iuvention to be secured by the herein-before in part recited Letters Patent,―
First, in painting generally, and in the impressing or printing of paper and
fabrics or stuffs, the use of gelatine fixed by means of tannin, as herein-before
described.
Secondly, the preparing fabrics or stuffs by successive immersions in baths
of gelatine and of tanning solutions, and afterwards ironing or warm mangling
or calendering them.
Thirdly, the coating of paintings, paper, orengravings with a varnish or coat
of artificial leather, as herein-before described.
Fourthly, the application of the said artificial leather cating for the
preservation of wood, plaster, stone, &c., and other organic substances.
And, fifthly, the manufacture of objects in "papièr mâché, in the manner
and as above described.
In witness whereof, I, William Clark, have hereunto set my hand and
seal, this Twenty-sixth day of June, One thousand eight hundred and
fifty-seven.
Witness,
WILLIAM G. E. SWINNOCK.
WILLIAM CLARK. (L.S.)