Improved, or Improvements connected with, Protective Covering for Surfaces.
Year: 1895

page_text: COMPLETE SPECIFICATION.
Improved, or Improvements connected with, Protective Covering
for Surfaces.
1, JOHN CARRINGTON SELLARS, of 68 Bridge Street, Birkenhead, in the
County of Chester, Manufacturing Chemist, 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 :-
This invention has mainly for its object to provide an improved or better, and
cheap, covering, for the surfaces of metals, and other materials perishable under
ordinary atmospheric and hydraulic influences and actions, or by acids, acid
materials, and corrosive substances, and the like, by which such materials will be
protected from the action of atmospheric air, water, acids, and any other gases or
fiquids; and it also has for its further object to provide a covering upon such
surfaces which shall be capable of withstanding pressures applied to it, and rubbing
actions thereon, such as by scrubbing or cleansing.
According to this invention, the materials employed, and the manner in which
the covering is applied, are as follows :-
I employ silicate of soda (preferably neutral); a suitable powder having
hygroscopic properties, an inert or insoluble powdered material, as finely ground
silica, barytes, whiting, French chalk, magnesia, and so forth, being suitable; and
water. That is to say, I use silicate of soda, a pulverulent material which will
take up water, and water (or other suitable liquid), which water when the covering
is heated, as hereinafter explained, will be driven off, and produce a state or
condition of porosity in the covering, the powder thus acting as a means of holding
water within the covering or compound, and when driven off by heat creating the
quality of porosity in it. This covering after being dried by air, say at a natural
temperature, is subjected to artificial heat, and the water held in it is driven off,
rendering it porous as above specified, and also anhydrous, by which it is rendered
capable of taking up or absorbing into itself, a substance or substances hereinafter
specified, in the manner hereinafter described, and facilitates and assures an active
combining action taking place between the two, and making it also hard, and its
adherence with the surface more keen and close.
Onto this surface 1 apply alumina in a suitable form as alum or other suitable
salt of alumina and then, when dry, subject it to artificial heat, whereby a combi-
nation between it and the first applied materials takes place, with the formation of
a compound, probably, more or less a silicate of alumina. In the operation upon the
covering by the artificial heat, if the alumina contains more or less water or
moisture, a certain amount of porosification takes place; and in such cases the
pores are better subsequently filled by applying over this covering any suitable
paint, oils, varnish, albumen, whitewash, Portland cement, or any suitable material
which will fill the pores, and not perish when in contact with the fluid or fluids or
matters with which it will or may come.
In some cases there may be added to the salt of alumina, a material as flour,
whiting, chalk, or coloured pigment, or the like, by which the surface will be tinted
or coloured.
One special set of materials or substances which I have used with success for
covering iron or metal surfaces, the covering made by which will withstand a rubbing
action, the action of air, or water, acids, alkali, acid or alkaline bodies, and the
like, and which will have a considerable length of life, or preserve its nature and
qualities a long time, is as follows:-
1. Silicate of seda, preferably neutral, and dilute, as one part of the silicate, at

page_text: about 100 Twaddle, to two parts of water; to which is added silica, as finely ground
calcined flints, this being added to the dilute silicate of soda to such an extent or
in such quantity as to produce a fluid of the consistency of a thin paint, capable
of being applied with a brush. The above mixture, when applied, (which is
conveniently done in the manner of paint) is dried, and artificially heated, as above
described.
2. Common commercial alum in a saturated solution, to which flour or other
suitable powder is added to bring it to the consistency of a thin paint, which is
applied conveniently in the manner of paint, and then artificially heated.
Before applying the materials to the surface to be covered, in the case of such
surface being a metal one, it should be clean or made bright. For instance, in the
case of iron or steel, the surface may be cleaned by rubbing it with holy-stone,
wire-brushes, or the like, previous to the application of the covering substances.
In the case of a body, to the surface of which the covering is to be applied, as
described, being in itself porous, the substance used in conjunction with the silicate
of soda above referred to, is not required; the body itself creating the necessary
porosity in the covering by absorbing the water, prior to the application of the
aluminous substance.
Besides the application of this invention to the surfaces of metals, it may be
applied to stone or any material in connection with which it is suitable, and capable
of withstanding the action and method employed in its application.
As regards the application of the artificial heat, the application of the covering,
for the purposes above described, where the bodies or articles being covered are
very large, the heating may be conveniently effected by jets of flame, produced in
and by suitable lamps or lights, the jets being directed onto the surface; while in
the case of the articles or bodies capable of readily being moved or handled, they
may be placed in an oven, or stove; or, if desired, heated by the action of a flame,
as in the former case.
As a modification under this invention, in some cases in lieu of using an aluminous
material, I employ lime, and apply it upon the first covering in a similar manner to
the aluminous material above described. In this case the finished or complete
casing would consist of or comprise a silicate of lime. For practical reasons,
however, I prefer the aluminous covering.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, it is to be stated that, while,
in the above Specification, I have set forth my invention applied in a manner which
may be adopted or used with success, yet it is not necessarily restricted to the
mauners of carrying it out therein more particularly specified, and that what I
claim in respect of this invention is :-
1. The herein described. new or improved covering for surfaces, namely, a
covering composed of or comprising silicate of soda, and a salt of alumina or lime,
and acted upon or subjected to heat; substantially as described.
2. The application to the surfaces of bodies such as referred to, of a covering,
first, of silicate of soda and a powdered material, and water, which are subjected
to artificial heat, and then subsequently alum or a suitable salt of alumina, or lime,
which are subjected to artificial heat; substantially as herein set forth.
3. The employment in connection with or for covering surfaces, of:-
(a) Silicate of soda and silica, in the form of a liquid, as hereinbefore
described.
(b) A solution of alum, and a powder, as specified, also in the form of liquid,
as herein before described.