AN IMPROVED PROCESS FOR RENDERING WALL PAINTINGS WEATHER-PROOF, AND FOR RENDERING PAINTINGS ABSOLUTELY
Year: 1882

page_text: LETTERS PATENT to Adolf Keim, of Munich in the Kingdom of Bavaria,
German Empire for an Invention of AN IMPROVED PROCESS FOR RENDERING
WALL PAINTINGS WEATHER-PROOF, AND FOR RENDERING PAINTINGS ABSOLUTELY
PROVISIONAL SPECIFICATION left by the said Adolf Keim at the Office of
the Commissioners, of Patents on the 21st August 1882.
AN
ADOLF KEIM, of Munich in the Kingdom of Bavaria, German Empire,
IMPROVED PROCESS FOR RENDERING WALL PAINTINGS WEATHER-PROOF, AND FOR.
RENDERING PAINTINGS ABSOLUTELY UNALTERABLE,
This invention consists in the first place of a process for rendering wall paintings
weather-proof, and embraces four consecutive steps or manipulations which will be
considered in their order, to wit:
First: The preparation of the prime ground and of the painting ground. A
new dry wall surface not yet plastered or an old wall surface cleaned of all plaster
is covered with common mortar of good quality so that all joints are covered and
unevennesses smoothened. On this the painting ground is laid 2 mm. thick, and
consisting of quartz and marble sand, calcined fossil meal and lime paste in proper
proportions. When dry, this is covered with silicated hydrofluoric acid, and then
impregnated with silicate of potash and saturated with silicic acid. This surface is
well washed before painted on. When walls are too moist or rotten for this
treatment, the painting ground will consist of especially prepared clay plates
properly cemented to the walls.
Second-The purification and preparation of the colors. The materials of which
they are composed must be of the same quality. Only mineral colors can be used.
They are finely powdered and mixed with soluble glass well saturated with potassa.
Then follows dilution with water and addition of carbonate of ammonia dissolved
in water. The colors are then deoxidized with warm water and receive an addition
of hydrate of alumina and magnesia. Furthermore, different quantities of fluorspar,
zinc oxide, pulverized marble and glass, manganese and carbonate of baryta are
added. The mixtures thus obtained are powdered in a mill.
Third: The preparation of the fixative. Silicate of potash, caustic ammonia,

page_text: caustic potash and pulverized marble, in proper proportions, are heated in an
air-tight pot in a water bath, cooled, poured off, and kept in glass jars ready
for use.
Fourth-The fixing of the painting. This is done with an atomizer furnished
with an arrangement to warm the fixative in a water bath. After the fixing, the
painting is moistened with carbonate of ammonia and washed with water to
eliminate any alkaline reaction. It is then warmed and impregnated with a
.solution of paraffine in benzole or the like. For the purpose of producing removable
wall paintings, the painting ground is placed on plates inserted in the wall.
This invention consists in the second place of a process for rendering paintings
absolutely unalterable. As a substratum, unpolished glass plates are used covered
on the back with lead foil or an equivalent. Common canvas may be used to paint
on, but it is preferable to steep it in baths of gypsum or baryta water, a solution
of silicate of potash and of silicated hydrofluoric acid. It is then washed with
water, and smoothened by warm iron cylinders and covered on the back. with an
oil ground. After the painting is executed, it is fixed and then washed with
carbonate of ammonia. These paintings may be finished in oil, in which caso they
are to be covered with an oil-varnish on completion; otherwise, with a shellac
varnish.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Adolf Keim in the Great Seal Patent Office on the 21st February
1883.
"AN
ADOLF KEI, of Munich in the Kingdom of Bavaria, German Empire,
IMPROVED PROCESS FOR RENDERING WALL PAINTINGS WEATHER-PROOF, AND FOR
RENDERING PAINTINGS ABSOLUTELY UNALTERABLE,"
This invention, which is applicable, to rendering both portable and fixed, i.e.,
stationary paintings weather-proof, consists of four operations or manipulations,
which are taken up in their turn, to wit:
First: The production of the prime ground and of the painting ground.
A new dry wall surface not yet plastered or an old wall surface cleaned of all
plaster, is cast or covered with common mortar of good quality, consisting of
slaked lime, washed quartz-sand, fossil meal and water, so as to make all joints,
uneven spots and rough parts smooth. Whenever water is mentioned in this
specification, it is understood to mean distilled, or filtered rain water.
The proportion of fossil-meal to sand in the above mortar should be as one to
six. After this cast has held for one day, it is thoroughly moistened, and then the
This ground
painting ground is put on, to a depth not exceeding two millimetres.
consists of four parts of pure white quartz-sand, three and a half parts of artificial
dust-free marble sand, one half part of fossil meal, and one and a half parts of
thick lime paste. When dry it is covered twice with a solution of silicated hydro-
fluoric acid, and then impregnated three or four times with silicate of potash
At the first and
chemically pure and completely saturated with silicic acid.
second impregnations, the silicate of potash should have a consistency of twelve
degrees Beaumé or a specific gravity of 1.090; at the third and fourth a con-
Each timo
sistency of 18 degrees Beaumé or a specific gravity of 1.140.
before a new layer is applied, the preceding one must have dried completely.
In order to remove the salts soluble in water which crystallize out during the
drying, the surface must be well and repeatedly washed before being painted on.
A dry wall surface composed of sound material, which is to serve as the prime
ground for a painting, is rare in new buildings and even rarer in older ones.
it occurs quite often that old, damp, rot infected places are to be painted on, and
for such instances the following supplementary manipulation is intended to secure
durability to the paintings on such defective walls.
But
The first step is to remove the causes of the dampness of the walls and to prevent
the further spread of the rot. [Vide pamphlet "Die Feuchtigkeit der Wohn-
Published by
gebauede." (The Humidity of Dwelling Houses) by A. Keim.
A. Hartleben, Vienna 1882.]. The surface of the wall, cleaned of all of its old
coating, its joints being scraped out to the depth of one centimetre, is exposed for
some days to the air to get dry. It is then carefully swept, and covered with an
extremely thin, watery mortar consisting of one and a half parts of cement, two
parts of pure quartz-sand and half a part of powdered manganese, to such a degree
of thickness that plates of clay, made expressly for the purpose can bo pressed on
to the same and held there. The surfaces of these should be well levelled by a
straight-edge. In this operation not more mortar should be used than is absolutely
necessary for the purpose.
These plates of clay are represented in the accompanying drawing forming a part
of this specification in which.

page_text: The plates should be made of a good, porous clay in two sizes and of thicknesses
varying from one centimetre to eight millimetres. If one size is made say twenty
by forty centimetres, the other should be five millimetres less in each dimension, or
nineteen and a half by thirty nine and a half centimetres. Into the larger plates A
are cut grooves a on one side. The smaller plates B are ribbed, also only on one
side. After having been thoroughly dried, all the plates are glazed on one side and
then placed in pairs one upon the other, with their glazed surfaces in contact, and
in such a manner, as shown in the drawing, that they are not flush with each other
but expose their glazed surfaces to the extent of about two centimetres. The
plates are baked in this position and, united by the glazing, they form one plate.
It is the grooved side that is pressed on to the mortar, the latter entering the
grooves so that when it is dry, the plate cannot be removed from it except in
pieces. The ribbed front of the plates offers a sufficiently large surface for the
painting ground. The manner in which the plates are placed one upon the other,
prevents the possibility of any humidity penetrating through the lower joints of
the plates where they are set together, as the free places are in each instance
covered by the overlapping part of the upper and outer plate.
The upper joints, formed by the circumstance that the upper plate is five milli-
metres smaller than the lower one, and of which the glazing of the lower plate
forms the ground, are then filled up with a thick cement made of oakum, tar,
asphaltum, turpentine and powdered manganesc. This cement is then melted in
with a hot soldering iron, so far that only half the depth of the joints is filled up.
The melting-in, however, is done only after the plates liave thoroughly dried in
position, say for a day or two. Then, with a rather thin mortar consisting of three
parts of washed quartz-sand, two parts of marble-sand, two parts of caustic lime,
one part of fossil-meal and one part of pulverized marble, the remaining portion of
the joints is well filled up, and the surfaces of the plates smoothly finished.
this level, the painting ground already described is laid on, and the manipulation
finished as specified.
Second The purification and preparation of the colors.
On
The first condition is that the materials from which the colors are made, be always
of the same quality, as this regulates the quality of the additions also. Only the
purest mineral colors, free from any artificial admixtures and adulterations, and
containing no substances destructible by heat, must be employed. Well fitted for
use are zinc oxide, artificially prepared iron oxides, all barytes and artificial mineral
colors free from sulphuric acid, Naples yellow, cadmium yellow, orange of chrome,
cobalt blue, ultramarine blue, cobalt green, ultramarine green, oxide of chrome,
hydrated oxide of chrome, chrome red, ultramarine red, German black, bone black
and ivory black. In fixing a painting the colors should suffer no change of shade in
consequence of the strong alcaline nature of the fixative, and should be freed from all
substances soluble in water and in potash-lye or subject to decomposition by soluble
glass. To prevent such a change, and to so purify the colors, they are finely powdered
and mixed with a certain quantity, according to their chemical properties, of dilute
soluble glass well saturated with potassa in which they are digested for some time.
Then follows dilution with water and addition of carbonate of ammonia in sufficient
quantity to eliminate or rather to decompose all the silicic acid contained in the
soluble glass. The colors, inixed most intimately in this way with hydrate of silica
in extremely fine particles, are then deoxidized with warm water and receive an
addition of a sufficient quantity of freshly precipitated hydrate of alumina and
magnesia until one hundred parts by weight of hydrate of silica dried at one
hundred degrees Réaumur, contain forty parts of hydrate of alumina and eighteen
parts of hydrate of magnesia. Both of these latter hydrates are also to be dried at
that temperature. Furthermore, different quantities of fluor-spar, zinc-oxide
pulverized marble and glass, manganese and carbonate of baryta are added to the
colors according to their chemical natures. The mixtures thus obtained are powdered
to the finest degree in a stone mill.
Third: The preparation of the fixative

page_text: Two litres of chemically pure silicate of potash, one of caustic ammonia, one
hundred grammes of caustic potash, and one hundred and twenty of pulverized
marble are heated together in an air-tight pot in a water bath during six hours.
It is then slowly cooled off and the liquid poured off and kept in well closed glass
jars or bottles ready for use.
Fourth: The fixing of the painting.
This is done with an atomizer furnished with an arrangement to warm the
fixative in a water bath. The painting must be fixed four or five times, during
which the temperature of the painting and of the surrounding atmosphere must be
raised to and maintained at from thirty to forty degrees Reaumur by coke stoves
in red heat, and care must be taken that the moist air constantly forming can
be drawn of from time to time. After the fixing, the painting is moistened with
carbonate of ammonia and then washed with distilled water until the latter no
longer shows an alkaline reaction. In order to render the face of the painting
absolutely insensible to the influence of water, it may first be warmed and then
impregnated with a solution of paraffine in benzole, petroleum, ether, turpentine or
similar substances. The paraffine is to act in no way as a binding medium, but
simply as a preservative. For the purpose of producing portable wall paintings,
the painting ground, instead of being put on or applied to a wall, is put on plates
of unpolished glass, stone, wire or the like, which are inserted into the wall after
the picture is painted. Then proceed as herein before indicated.
Having thus described this invention, what I claim is:
FirstA wall plaster or painting-ground consisting of caustic lime, quartz-sand,
pulverized marble and fossil-meal, developed by silicated hydrofluoric acid
and hardened by silicate of potash, substantially as described and for the
purposes set forth.
Second-The process of manufacturing painters' colors, shaded by silicate of
potash and mixed with hydrate of magnesia and alumina, fluor spar, zinc
oxide, pulverized marble or glass, carbonate of baryta, and manganese,
substantially in the proportions specified.
Third: A fixative for paintings consisting of chemically pure silicate of potash,
caustic ammonia, caustic potash and marble, substantially in the proportions
specified.
Fourth Plates of clay, A, with grooves a a, in combination with plates of clay, B,
ribbed as shown, both being glazed on their inner surfaces and joined
together, substantially as described and for the purpose set forth.
In Witness whereof I, the said Adolf Keim have hereunto set my hand
and seal this seventeenth day of February AD 1883.
ADOLF KEIM (LS.)