IMPROVEMENTS IN NONCONDUCTING COM- POSITIONS OR MATERIALS FOR COVERING STEAM BOILER AND OTHER SURFACES."
Year: 1881

page_text: LETTERS PATENT to Daniel Henry Dade, of Bermondsey, in the County of
Surrey, for an Invention of "IMPROVEMENTS IN NONCONDUCTING COM-
POSITIONS OR MATERIALS FOR COVERING STEAM BOILER AND OTHER
SURFACES."
PROVISIONAL SPECIFICATION left by the said Daniel Henry Dade at the
Office of the Commissioners of Patents on the 18th March 1881.
DANIEL HENRY DADE, of Bermondsey, in the County of Surrey. " IMPROVE-
MENTS IN NONCONDUCTING COMPOSITIONS OR MATERIALS FOR COVERING STEAM
BOILER AND OTHER SURFACES."
According to this Invention I make compositions of silicate cotton, and other
materials, which shall be easy of application and if need be of removal for repairs
of the boiler or other surface covered thereby.
It has hitherto been difficult and expensive to apply silicate cotton on a large or
commercial scale to such purposes, owing to the necessity for special means for
holding the material in place; the material had thus to be stuffed underneath an
outer covering of sheet iron or a wood lagging fastened on a wooden frame-work;
this entails, however, so great expense that other nonconducting material or
compositions have been given the preference, although inferior to silicate cotton or
as nonconductors of heat or sound; the silicate cotton has also been placed in a
kind of mattress or beneath a cover of canvas sewn on to hoop iron or wooden
frames in order to reduce the expense of application, but this kind of covering is
bulky in appearance, very liable to shift, and also easily crushed when trodden on
by men working on or passing over the top of a boiler; silicate cotton has also
been mixed with a thick clay wash, forming a kind of cement, which is adhesive to
a hot surface, so as to need no outer covering, but as the clay clogs up the fine
interstices or air spaces between the fibres of the silicate cotton the nonconducting
properties are greatly impaired.

page_text: The object of my Invention is so to treat silicate cotton as to glue or stick some
of the fibres together without clogging up the air spaces, the material at the same
time affording the required adhesion to the boiler or other surface. The result of
treating the silicate cotton according to my Invention is that the liquid with which
it is treated or permeated by the application of heat is driven to the surface of
the layer in which I form the silicate cotton, forming thereon a comparatively hard
protecting skin, while the interior of the layer is left comparatively soft and elastic
and quite porous, having an appearance somewhat like felt. The consistency and
nonconducting properties of the material are not impaired to any sensible degree,
whilst the application is easy and inexpensive. The outer skin may, moreover,
when dry, be rendered still harder by a coating of coarse calico or common paper,
which may be painted or tarred. The liquid employed in the treatment of the
silicate cotton consists of a decoction of Irish moss, which may be mixed with thin
boiled starch.
According to one mode of manufacture I put a small quantity of the decoction
in a vessel or vat; I then form a layer of silicate cotton thereon by spreading it
thereon; on the top of that I pour more of the decoction, and I may thus alternate,
three or more times, heat being applied to the vessel underneath or by other means;
the decoction in a short time thoroughly penetrates the silicate cotton, making it
into a kind of cement in order to let the heat and steam or vapors rise or circulate
freely. I prefer to place one or more pipes or hollow shafts in the vessel.
The material is then removed from the vessel and gently stirred or mixed on a
board or floor; or I may put water only in the bottom of the cistern or vessel and
rest the silicate cotton on a removable grid above it so as to let the steam from the
water permeate the silicate cotton and facilitate the saturation of it with the
decoction.
With the above compositions or material I may use cow hair, paper pulp, and
hacklings, or fibrous material, cut rather short to prevent the decoction from
turning sour. I may use a small quantity of tannic extract or alum and cloves or
borax.
The composition is put into casks, and may be applied to the boiler or other
surface in one or more layers to a thickness of about one to three inches. In
some cases, especially for pipes for vertical surfaces and for very hot surfaces, I use
for the first layer a composition of silicate cotton and the decoction containing a
proportion of clay.
I may also form the material into boards, which, for the better preservation in
transport and handling, and especially for large sizes, may be covered with thin
cheap paper or coarse canvas or other fabric. Such board can, while still wet
any time after when damped, readily be bent to be adapted for curved surfaces.
When dry and set these boards are ready for transport. I join these boards by
means of the aforesaid composition and keep them in place by means of wire
netting or wires and canvas.
When the boiler or other surface has been coated as described I paint, tar, or
varnish the composition itself or the paper or canvas covering thereof.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Daniel Henry Dade in the Great Seal Patent Office on the
17th September 1881.
DANIEL HENRY DADE, of Bermondsey, in the County of Surrey. "IMPROVE-
MENTS IN NONCONDUCTING COMPOSITIONS OR MATERIALS FOR COVERING STEAM
BOILER AND OTHER SURFACES."
According to this Invention I make compositions of silicate cotton ‘and other
materials of a fibrous heat nonconducting nature, such as asbestos, vegetable fibre,:
and hair, which shall be easy of application, and, if need be, of removal for repairs
of the boiler or other surface covered thereby; also to make such compositions not
liable to crack by great heat, and to render them incombustible. The object of my
Invention is also to stick or glue some of the fibres together without clogging up
the air spaces, the material at the same time affording the required adhesion to the
boiler or other surface.
It has hitherto been difficult and expensive to apply such fibrous materials, and
more especially silicate cotton on a large or commercial scale to such purposes, owing
to the necessity for special means for holding the material in place; the material
had thus to be stuffed underneath an outer covering of sheet iron, or a wooden
lagging fastened on a wooden framework; this entails however so great expense
that other nonconducting materials or compositions of a non fibrous nature have
been given the preference, although inferior to fibrous materials, such as silicate
cotton, as nonconductors of heat or sound. The silicate cotton has also been placed
in a kind of mattress, or beneath a cover of canvas sewn on to hoop iron or wooden
frames, in order to reduce the expense of application, but this kind of covering is
bulky in appearance, very liable to shift, and also easily crushed when trodden on
by men working on or passing over the top of a boiler, Silicate cotton has also
been mixed with a thick clay wash, forming a kind of cement which is adhesive to
a hot surface so as to need no outer covering, but as the clay clogs up the fine
interstices or air spaces between the fibres of the silicate cotton the nonconducting
properties are greatly impaired.
The object and result of my Invention is also to make the aforesaid fibrous
materials, and especially silicate cotton, applicable to many purposes to which they
could not hitherto be applied.
The result of treating the silicate cotton, according to my Invention, is that the
liquid with which it is treated or permeated by the application of heat is driven to
the surface of the layer in which I form the silicate cotton, forming thereon
comparatively hard but elastic protecting skin, while the interior of the layer is
left comparatively soft and elastic and quite porous, having an appearance somewhat
like felt, and it is thereby also prevented from cracking. The consistency and non-
conducting properties of the material are not impaired, but rather increased, whilst
the application is easy and inexpensive and obviates the necessity of an outer casing
of sheet iron, wooden lagging, or other materials to serve as a protection and for
keeping the cotton in its place. The outer skin may moreover, when dry, be
rendered still harder by a coating of coarse calico or common paper, which may be
painted or tarred.
The liquid employed in the treatment of the silicate cotton consists of a decoction
of Irish moss or other similar lichen, which may be mixed with thin boiled starch,
or with a decoction of silicate of potash or silicate of soda and water previously
softened, say, one part of the former and three of the latter, to which may be added
a solution of a small proportion of gum arabic and isinglass; or I may use a strong

page_text: decoction (say, 25 lbs. of moss to 50 gallons of softened 'water) boiled for several
hours.
In order to prevent the aforenamed solution from charring when exposed to high
heat, or from burning when exposed to fire, I mix with it a solution of a material
called trass, which is found in some parts of Germany, notably in the Rhine district.
There are two qualities of this trass, the white and the blue, and it is preferable to
mix these two kinds; and dissolve them'in water. This'trass, being of a very rich
and fatty nature, can only be dissolved after having been immersed in water for a
very considerable time, and even then it is so difficult to blend that I prefer to use
.steam power for working it.. This solution needs' only be a comparatively thin
one; I use about 1 cwt. of trass to about 250 gallons of water, from which as much
of the lime as possible has been taken by filtration or otherwise, and which has
previously passed through decayed vegetable matter, in order to render it soft and
easily workable. The solution, when mixed with the decoction above described, has
the following effect when mixed with silicate cotton or other fibrous materials,
such as hair or vegetable fibre when dried. either in the open or through heat,
viz.:―
Contrary to the action of clay it does not solidify these materials, nor does it
barden them or make them dense, or fill up the air cells between the fibres, thereby
destroying the non-conducting properties of these materials, and cracking them
when exposed to the heat of fire. On the contrary, it gives to these fibres, and
especially so to the silicate cotton, a certain amount of elasticity, and not only does
not destroy the air-cells, but gives to the whole a porousness something resembling
pumice stone. This trass is of itself an excellent non. conductor, having in that
respect similar properties to infusoria or infusorial earth, which, especially in
Germany, is used for covering boilers mixed with lime or cement. This however
is a mistake, as the latter materials are not proof against cracking, and besides to
a large extent destroy the non conducting properties of the infusorial earth. Trass
and infusoria have much similarity between them, and belong to the same class in
geology. The principal difference is that the former, when dried by heat, has
extreme adhesive properties, whereas the other has none whatever.
The addition of the other decoction has the effect of making the whole much
lighter and softer inside. The two combined have the effect of producing powerful
adhesion of any fibrous material it is mixed with, to either a hot or a cold surface
when applied wet, and when dried by heat or otherwise leaving the interior soft,
porous, and in every respect non radiating, sound proof, and frost proof, and
rendering the outer surface hard and elastic. This is especially suitable for
covering boilers, pipes, cylinders, and so forth, and I give the whole combination
the name of silicate cotton composition.
To prevent any portion of the mixtures or solutions, especially the vegetable
portions thereof, from decaying, turning sour, putrifying, or rotting, and to make
the silicate cotton or other fibrous materials used by me for various purposes,
especially for building and domestic purposes, proof against rot, mildew, and
vermin, such as earwigs (to which silicate cotton when applied in the loose or raw
state is even more liable than felt, sawdust, and such like, and also for preventing
the emission of sulphuretted hydrogen by contact with acids, which, especially for
domestic and building purposes, and when used for lining vessels and receptacles
containing food, is of the greatest objection. I use a large proportion of tamic
extract, chiefly obtained from refuse from the tan yard (bark I have found to be
decidedly objectionable), and I prefer in many instances to boil the whole of my
decoctions or mixtures for several hours in a strong tamic solution instead of
water, but in that case it is necessary to soak all the vegetable ingredients for at
least a whole night in water.
In order to counteract the emission of sulphuretted hydrogen, and to a certain-
extent making silicate cotton into a kind of slabs, styled slag felt, solutions such
as common soda or silicate of soda have been and are being used, but not only do

page_text: •
the crystals formed on the surface of the cotton by-these. means make the material:
strongly hygroscopic, so that in damp buildings it will always be wet, but the
slabs can only be made in very small sizes, say, 6 inches x 12 inches, necessitating
a good deal of labor.
İ
"
According to one mode of manufacture I put a small quantity of the whole of
the decoction mixed with the solution of trass into a large vessel or tank. I then
form a layer of silicate cotton thereon by spreading it. thereon, on the top of that I
pour more of the decoction, and I may thus alternate three or more times. Heat
may be applied to expediate the action. The whole solution in a short time
thoroughly penetrates the silicate cotton, making it into a kind of mortar.
The material is then removed from the vessel and gently stirred or mixed on a
board or floor.
:
The composition is put into casks and may be applied to the boiler or other
surface in one or more layers to a thickness of about one to three inches. In some
cases, especially for very hot or superheated surfaces, I use for the first layer a
mixture of the silicate cotton and the decoction containing a large proportion of
trass solution.
I may also form the material into boards in order to facilitate the application of
silicate cotton and other fibrous material for covering boilers and other surfaces for
the various purposes already named and to make them especially applicable to cold
surfaces; and also to make them more suitable for transport, I mix them with all or
some of the aforementioned decoctions or solutions, and put the whole in a
consistency resembling mortar to moulds and roll this material into a kind of
boards of various thicknesses or sizes. I then prefer to place these boards on
wooden trays and place them in a strong current of air or exposed to the sun until
they are dry, or I may, when they are half dry, expose the boards to hot air, which
has the effect of giving them a barder surface; this is especially when boards of
large sizes, say over 3 feet x 1 foot are required.
These boards I can make either flat or curved in order to suit the form of any
surface to which they may be applied; this I effect by placing them, when partly
dry, on moulds or sheets of iron bent to the requisite proportions on which I allow
them to dry.
I may or may not provide these boards with a backing of canvas or strong
textile material or thin sheets of tin or zinc overlapping the boards, say from one to
three inches, both on one side and at one end, so as to make them keep and
adhere closer together when placed side by side, and these overlaps fastened or
secured over each board adjoining, thus make the whole of the covering as it were
self supporting and the whole surface continuous.
I may also make these boards suitable for covering steam pipes. I curve them
to such an extent as to give them the exact shape of a half circle. Two of these
form a ring or cylinder when placed together, and to keep them in that position I
give them a backing of canvas or strong textile material, or thin sheet tin or zinc.
This backing also is made to overlap at one end so as to cover each ring adjoining,
and it has an overlapping strip along one side which can be fastened down after
the ring (which is made so as to open and shut in the same way as a portmanteau)
is clasped round the pipe.
The crevices, between these boards or rings, can be filled up with my silicate
cotton composition above described.
I need not necessarily make these boards or rings entirely solid, that is to say,
entirely made of this composition, as for some purposes it is preferable to employ
what I term silicate cotton sheeting.
The sheeting I can form by having alternate layers of the aforenamed compo-
sition, and the loose silicate cotton in between. I make these sheets either in
moulds or not, as they can at any time be cut to the required sizes.
This process of placing loose cotton between two or more layers of the com-
position, which to a certain extent has been allowed to penetrate into the cotton

page_text: makes the whole much lighter in weight, and has the effect of making the sheeting
sufficiently pliable, and I may adopt the same method for making my rings for
pipes, with the backing added as before described. I sometimes prefer to make
this sheeting of alternate layers of loose silicate cotton and of paper of a woolly
and porous nature, or of paper felt or of some textile material, after having covered
it on either or both sides with my silicate cotton composition, viz., silicate cotton
mixed with all or some of the ingredients before described by adopting the same
treatment as hereafter described for making wooden or other walls fireproof. This
would be specially preferable for sheets of large sizes, or for sheeting which requires
to be bent to a certain extent or to be pliable.
This sheeting is especially suitable for lining walls, partitions, doors, ceilings,
roofs, fireproof rooms, sheds, field hospitals, barracks, and so forth, and also for
lining refrigerators and cooking stoves.
The sheeting can be made from inch thick upwards, but when they are required
thin and more than two feet square they are very liable to break in transit or when
being handled, and I therefore-give them sometimes a backing of thin paper or
textile material. As however these sheets are often exposed to heat I make the
paper or textile material fireproof, by previously, or after having been adjusted
on the sheets, saturating them with a thin solution of trass and silicate of soda or
potass.
I also find that by the aid of a combination of all or some of the before described
materials I may make wood, felt, lathing, stage scenery, and in fact all inflammable
materials fireproof by covering them with a thin layer of "the silicate cotton
composition" before described.
In order to make the composition adhere I give the wooden or other combus-
tible surface a coating of the aforesaid decoction, and apply to the coating while
wet a thin layer of the "silicate cotton composition."
The surface is then sufficiently hard to paper or paint it, and the surface will
not take fire. In this way I can make a whole building to a very large extent
fireproof, especially as this thin layer is sufficiently tough to prevent cracking when
exposed to great heat.
And having thus described and ascertained the nature of this Invention, and the
manner of carrying the same into effect, I declare that I claim,-
First. Treating silicate cotton and other fibrous substances such as hair, vegetable
fibre, and asbestos with a decoction of Irish moss or similar glutinous substance
with or without the admixture of thin boiled starch, or of a decoction of silicate of
potash, or of a decoction of silicate of soda, to which glutinous decoction especially
for resisting high heat may be added a solution of trass so as to render the silicate
cotton sufficiently self adhesive and coherent, all substantially as set forth, for the
purpose of doing away with an outer casing or means for holding the silicate 4
cotton in place, and to give it an exterior hard and elastic protecting skin which
is not liable to crack by great heat without detracting from its nonconducting
properties.
Second. The manufacture from silicate cotton of sheets flat or curved, which
resist fire, heat, damp, vermin, and transmission of sound, and are easy of
transport, application, and removal, all substantially as and for the purposes
described.
Third. The manufacture of cylindrical coverings in two halves for protecting
pipes against radiation of heat, such coverings having a canvas or other backing,
and being self supporting, all substantially as set forth.
Fourth. The manufacture from silicate cotton and other fibrous substances such
as cow hair, asbestos, and vegetable fibre, of a kind of mortar or cement which is
highly nonconducting and heat resisting, and not liable to crack by heat, and
which may be applied for protecting against heat, radiation, and for rendering
combustible surfaces fireproof.
Fifth. The manufacture from the "silicate cotton composition" of boards flat or

page_text: curved for the purpose of covering boilers for preventing radiation, and if desired
provided with a backing, all substantially as set forth.
In witness whereof, I, the said Daniel Henry Dade, have hereunto set my
hand and seal, this Fourteenth day of September, in the year of our
Lord One thousand eight hundred and eighty one.
.Tדרד
TT
DAN'. H. DADE. (L.S.)