Manufacture of an Improved Compound for Coating Walls and other Surfaces, and for the Production of Casts or Mouldings, and for Analogous Purposes.
Year: 1891

page_text: The decision of the Comptroller-General, of the 31st day of May 1894, allowed,
under Section 18 of the Patents, &c. Act, 1883, an Amendment of this
Specification.
Date of Application, 4th Dec., 1891
Complete Specification Left, 26th Mar., 1892-Accepted, 30th Apr.,
1892
PROVISIONAL SPECIFICATION.
The Manufacture of an Improved Compound for Coating Walls and
other Surfaces, and for the Production of Casts or Mouldings, and
for Analogous Purposes.
I, ROMULUS NORWOOD, of 30, De Crespigny Park, Denmark Hill, in the County
of Surrey, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the manufacture of an improved adhesive compound for
coating walls and other surfaces, and for the production of casts or mouldings and
for analogous purposes.
The object of my said invention is to produce an adhesive compound somewhat
similar to that now commercially known as "alabastine," but which, when mixed
with cold water, will work more efficiently and advantageously than the said
alabastine now does.
My improved compound consists essentially of animal glue and a suitable base,
such as calcined gypsum, treated as hereinafter mentioned so that the said compound
can be made available for use by the addition of cold water.
In the manufacture of my improved compound, I mix the glue and the gypsum
or other base in suitable proportions, and then subject the mixture to heat. By
this treatment, the glue is brought into such a condition that it can be readily
reduced to such a degree of fineness as to enable the compound to be advantageously
prepared for use by the addition thereto of cold water. I thus produce an adhesive
compound which can be used for relief work, modelling and similar work, as well as
for coating and finishing walls and other surfaces.
I find it advantageous to mix a small proportion of sulphate of zinc or an
equivalent substance with the glue and the gypsum or other base.
Dated this 4th day of December 1891
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.
COMPLETE SPECIFICATION (AMENDED).
The Manufacture of an Improved Compound for Coating Walls and
other Surfaces, and for the Production of Casts or Mouldings, and
for Analogous Purposes.
I ROMULUS NORWOOD of 30, De Crespigny Park Denmark Hill, in the County
of Surrey Manufacturer do hereby declare the nature of this 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 the manufacture of an improved adhesive compound for

page_text: coating walls and other surfaces and for the production of casts or mouldings and
for analogous purposes.
The object of my said invention is to produce an adhesive compound somewhat
similar to that described in the Specification of former Letters Patent dated
4th April 1882, No. 1620, and now commercially known as "alabastine," but which
when mixed with cold water, will work more efficiently and advantageously than
the said alabastine now does.
For this purpose, I mix together in suitable proportions strongly adhesive animal
glue and a suitable base such as gypsum or wholly or partially calcined gypsum and
subject the mixture to heat, supplying moisture if necessary. By this treatment,
the glue is rendered friable, and, the gypsum and glue being intimately mixed,
a compound is formed which can be readily reduced to such a degree of fineness as
to enable the same to be advantageously prepared for use by the addition thereto
of cold water. The adhesive compound thus produced can be used for relief-
work, modelling and similar work, as well as for coating and finishing walls and
other surfaces.
Heretofore it has been necessary to use hot water for preparing alabastine for use,
because if this compound, as hither made, were mixed with cold water, its adhesive
property would be deteriorated to such an extent that, when applied to walls and
other surfaces, it would be liable to be easily detached therefrom; and considerable
inconvenience has sometimes been caused by the alabastine having been mixed, by
mistake or by negligence, with water not sufficiently hot to impart the required
degree of adhesion to the coating or covering. By my invention, however, I avoid
all such inconveniences.
I find it advantageous, in some instances, to mix a small proportion of sulphate of
zinc or an equivalent substance with the glue and the gypsum or other base.
In making an alabastine compound according to my said invention, I find it
advantageous to proceed as follows, that is to say :-I put the gypsum into a
suitable vessel or pan and apply heat thereto so as to calcine the gypsum. While
the gypsum is being thus calcined, or after it has been calcined and while it is in a
hot condition, I slowly pour into the vessel or pan containing the gypsum, animal
glue which has been previously dissolved in water, at the same time stirring the
mixture in the said vessel or pan and maintaining the heat therein.
By this means, the water from the glue solution is driven off with the water of
crystallization of the gypsum, if any, rendering the glue friable so that it can be
reduced to a fine state of division, and the atoms of the glue are thoroughly inter-
mixed with those of the gypsum. The compound of glue and calcined gypsum thus
produced can be more readily reduced to a very fine powder than if the calcined
gypsum and the glue were simply ground together.
Or I put dry animal glue, either ground or in lumps or pieces, into the vessel or
pan containing the heated gypsum. In this case, moisture is liberated from the
gypsum by the heat applied to the said vessel or pan, the glue is rendered friable
by the action of the said moisture and by the heat and the gypsum and glue being
intimately mixed, a compound is produced which, when ground, will properly mix
with cold water, and, when so mixed and applied to a surface, will effectually
adhere thereto. If the gypsum does not contain enough moisture to ensure an
efficient action upon the glue (as is usually the case when calcined gypsum is reheated),
a suitable quantity of water or steam is introduced into the vessel or pan.
When sulphate of zinc is used, I either introduce it directly into the vessel or
pan, or I add it in a finely divided condition to the compound after the latter has
been removed from the said vessel or pan.
The proportions of the several ingredients which I find it advantageous to adopt
are as follows, viz. :-To every hundred-weight (112 lbs.) of the calcined gypsum, I
add from five to eight pounds of animal glue, and from half-a-pound to one-pound-
and-a-half of sulphate of zinc or its equivalent when such substance is used. The
proportions will, however, be varied to some extent according to the purpose for
which the compound is required, and according to the strength of the glue employed.

page_text: But a sufficient quantity of animal glue must be used, in the manufacture of my improved
compound, to impart to the said compound the requisite degree of adhesiveness for the
purposes herein specified, without impairing its setting property.
In order to ensure the most efficient working of the compound in respect of both the
adhesion and setting thereof, I use the better qualities of animal glue, as the cheaper
qualities of glue, such as are generally employed for merely retarding the setting of
plaster, even when used in or about in the proportions above stated, will not impart the
desired degree of adhesiveness to the compound.
Suitable colours may, if desired, be added to the compound as it comes from the
pan to produce tints other than white, the said colours being ground in, if necessary,
by any convenient means. Or the said colours can, in some instances, be put into
the pan and mixed with the compound therein.
Instead of the sulphate of zinc, I can, if desired, use other mineral salts, the
objects being to neutralize the retarding effect of the glue upon the setting of the
plaster and to add to the hardness of the material when set.
A useful compound
can, however, be made according to my invention without the addition of such
salts.
It is obvious that I can, if desired, most advantageous to use, in my process, gypsum
previously calcined, the glue, in this case, being introduced with moisture, steam or
water being added, or the glue being first dissolved and then introduced in a liquid
state, and the calcined gypsum being reheated to the required temperature after being
mixed with the glue.
Although in the said former Specification, it is stated that the gypsum and glue
must be in a very finely divided condition, there is also a statement therein that, to
prepare the compound for use, the ingredients mixed and in a loose condition are
dissolved in very hot water. And the use of hot water for this purpose has hitherto
been necessary by reason of the fact that the glue, though reduced to a comparatively
fine state of division, was not previously rendered friable and could not be so
minutely divided as to admit its use with cold water, consequently the compound
had to be dissolved in very hot water in order to bring the glue into such a
condition as to ensure the efficient working of the said compound.
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 :-
:-
First. In the manufacture of a compound for the purposes above specified, the
rendering of the animal glue friable by subjecting it to the action of moisture and
heat while mixed with the gypsum or other base, substantially as hereinbefore
described.
Second. First. The improved process above described, consisting essentially in
mixing animal glue and gypsum (or wholly or partially calcined gypsum) or a similar
base in or about in the proportions above stated (with or without a small proportion
of sulphate of zinc or its equivalent) and applying heat for the purpose of rendering
the glue friable, so that the resulting compound will work efficiently when mixed
with cold water, the said compound, if desired, being finely ground.
Third Second. The improved process above described, consisting in heating
gypsum (or wholly or partially calcined gypsum) or a similar base in a vessel or
pan, slowly pouring into the same while in a heated state, in or about in the above
named proportions, animal glue which has been previously dissolved in water, and
then evaporating the water and reducing the compound to a very fine powder,
with or without the addition of sulphate of zinc or its equivalent, for the purposes
specified.
Fourth. Third. A dry compound, such as above described, consisting essentially of
animal glue and a base such as calcined gypsum, in or about in the above named
proportions, in such a fine state of division that the said compound will work
efficiently when mixed with cold water.
Fifth Fourth. The improved compound consisting of animal glue and a base

page_text: such as calcined gypsum in or about in the above named proportions (with or without
a small proportion of sulphate of zinc or its equivalent) intimately united or
combined and rendered friable by the application of heat, substantially as herein-
before described..
Dated this 26th dor of March 1900
ROMULUS NORWOOD.
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.