IMPROVEMENTS IN THE COMPOSITION AND MANUFACTURE OF PAINTS APPLICABLE TO IRON AND OTHER SHIPS' BOTTOMS. AND FOR OTHER GENERAL PURPOSES
Year: 1865

page_text: LETTERS PATENT to Thomas Spencer, of 32, Euston Square, in the
County of Middlesex, Chemical Engineer, for the Invention of
"IMPROVEMENTS IN THE COMPOSITION AND MANUFACTURE OF PAINTS APPLICABLE
TO IRON AND OTHER SHIPS' BOTTOMS. AND FOR OTHER GENERAL PURPOSES."
Sealed the 24th November 1865, and dated the 31st May 1865.
PROVISIONAL SPECIFICATION left by the said Thomas Spencer at the
Office of the Commissioners of Patents, with his Petition, on the
31st May 1865.
I, THOMAS SPENCER, of 32, Euston Square, in the County of Middlesex,
Chemical Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE COMPOSITION AND MANUFACTURE OF PAINTS APPLICABLE
TO IRON AND OTHER SHIPS' BOTTOMS, AND FOR OTHER GENERAL PURPOSES," to be as
follows:-
The first part of this Invention consists in the application of a mineral
or other proto-carbonate of iron, known to mineralogists as spathose. ore, for
the purpose of a pigment or paint, the same to be used with oil, turpentine,
or varnish, or any of the ordinary media in which paints are usually mixed.
The same may be used in mixture with any other pigment, or alone, according
to circumstances. To prepare this proto-carbonate paint for the purpose of

page_text: this Invention, the raw ore is first to be crushed and then ground into powder.
It is then to be mixed and ground along with any of the above-named media
until it acquires the consistency of ordinary paint, in which state, after mixture
with a sufficiency of any drying material, it may be applied to surfaces in the
ordinary way.
The second part of this Invention consists in the application of a powder of
iron in the metallic state, for the purpose of preventing the well-known
animal and vegetable encrustation or fouling to which the bottom of iron and
wooden ships are liable, and to other surfaces when submerged in sea or other
water. Metallic powder for the purposes of this part of the Invention is
conveniently obtained from steel, iron, or cast-iron filings or turnings, which
on being passed through a fine sieve are mixed with oil, turpentine, or any
varnish, or other of the common media with which pigments are mixed. It
is then to be ground up to the consistency of a coarse paint, in which state it
may be applied to the surfaces already named. This mixture of metallic iron
may be used alone, or with a proportion of any other pigment, such as white
lead, oxide of zinc, or the spathose ore which is referred to in the first
part of this Invention.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Spencer in the Great Seal Patent Office on
the 30th November 1865.
TO ALL, TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SPENCER, of 32, Euston Square, in the County of Middlesex, Chemical
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of May, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Spencer, Her special licence that I, the said
Thomas Spencer, my executors, administrators, and assigns, or such others as
I, the said Thomas Spencer, 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 THE COMPOSITION AND MANUFACTURE OF PAINTS APPLICABLE

page_text: TO.
IRON AND OTHER SHIPS' BOTTOMS, AND FOR OTHER GENERAL PURPOSES,"
upon the condition (amongst others) that I, the said Thomas Spencer, 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 Thomas Spencer, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement:-
The said Invention consists, in. the first part, of an application of a
ferruginous mineral known to mineralogists as "spathose ore for the
purpose of a pigment or paint, to be used in mixture with oil, turpentine, or
varnish, or any media with which paints, such as white lead, are usually
mixed. The same substance, is also known to chemists as the "proto-
carbonate of iron," and though it may be prepared artificially by well-known
chemical methods, yet for the sake of economy prefer to make use of the
natural ore.
The paint prepared from this substance may be used alone or in mixture
with any other pigmentary basis, such as white or red lead, or other metallic
oxides, carbonates, or sulphates, and also with the ordinary earthy or chemical
pigments which are added for the purpose of giving the requisite colour.
The same ferruginous carbonate (spathose ore) may also be converted for.
use as a black paint by eliminating its carbonic acid in a retort or oven by
means of a moderate heat, not under 600 degrees of Fahrenheit, or its
blackness may be further increased by placing in mixture with it one-sixth of
its weight of charcoal, which mixture must be kept at a dull red heat for
from 9 to 12 hours, by which the oxide or its carbonate becomes; converted
into a black friable substance, well fitted for the purposes of this Invention.
The simple oxide, or that prepared in combination with the carbon, is then to
be mixed with oils or varnishes in the manner herein described. To make
the carbonate or the black oxide into paint, the dry substance, must in each
case be first broken into small nut-like pieces and then crushed into powder
and passed through a fine sieve. The sifted powder is then. to be mixed with.
a sufficient quantity of raw linseed oil, and rendered, into a thick magma,
after which it is put into a paint mill, of any construction, and ground as
fine as deemed necessary. When thus treated the thick product, of the mill

page_text: is to be thinned to the proper working consistency, by adding to it either raw
or boiled linseed oil, or spirits of turpentine or varnish, or all these in the
proportions well known to painters, and to which is to be added the requisite
quantity of the well-known body termed "driers." At this stage the paint is
ready for application with brushes in the ordinary manner; two, or three, or as
many coatings of it are given as the nature of the work may render necessary,
though as a rule a less number are required than of those paints which are
chiefly composed of white lead, the ferruginous paint being so much superior
in body. Though the colour of the paint made from the natural ore in the
carbonated state is dark cream colour, it may be altered at pleasure by adding
to it any of the ordinary coloured pigments. The black or oxide paint may
also be used in mixture with other pigments if desired, though I prefer that
it should be used alone as a black paint, especially if applied for the
preservation of metals.
The said Invention consists, in the second parts, of the application of metallic
iron in fine powder for a paint to prevent the adhesion of the well-known
animal and vegetable bodies which so injuriously "foul" the immersed portion
of iron ships, as well as in many instances those of wood. The same paint
is applicable to any other surfaces which are liable to be fouled by submersion
in sea or other water. A sheathing of copper or its alloys has hitherto been
found the most effective remedy against this species of fouling; at the same
time it has been generally believed that this is due to the poisonous action of
the cupreous oxide or its carbonate, which thus prevents these marine.bodies
from fastening themselves on submerged surfaces covered with this metal.
That the carbonate of the oxide of this metal prevents this injurious adhesion
is no doubt true, but it does not do so as a consequence of its poisonous nature,
but simply because the green chalky surface of the carbonate of this metal
affords no firm holding by which a vacuum can be formed to enable animal or
vegetable life to adhere firmly to the vessel as it moves through the water.
There are few but what in boyhood have experienced a difficulty of the same
nature in getting the well-known leather "sucker" to adhere to a stone which
happens to have a rough or friable surface; such a difficulty is experienced
by the living bodies in question, in attaching themselves to the loose surface
of the carbonate of copper. Had this now important problem been earlier
seen from this point of view it would no doubt have been solved before this.
but so long as it was believed that a paint of a poisonous nature was requisite
the object was sought for in this the wrong direction. The application of
copper sheathing to iron vessels being attended with so much difficulty and
expense, as well as the danger of galvanic corrosion being induced by it on
.

page_text: the surface of the iron it was meant to preserve, a paint that should in some
mauner fulfil its functions has been the object long sought. From the
experiments I have been enabled to make from time to time I believe a
remedy will be found in the following species of paint, the chief ingredient
of which is metallic iron. For such a paint I obtain metallic iron powder,
most conveniently from steel, iron, or cast-iron filings or turnings, which on
being passed through a fine sieve, the resulting metallic powder is mixed into
a magma with linseed oil, turpentine, or any of those varnishes with which
paints are usually mixed, after which it is put into a mill and slightly ground
to the consistency of a coarse paint; it is then to be thinned down for use
like any other paint, with such oil or varnish as may be judged desirable for
the work; when in this state it is ready to be laid on in the usual manner
with a brush. In applying this paint it may be mixed with either of those I
have above described, or with ordinary white lead paint. In all cases where
the object is to prevent fouling for a length of time, two or more coatings are.
necessary. When a sufficient number of coatings are given, and the work
thoroughly dry, its surface must be slightly rubbed with grit or pummicestone,
or with coarse glass paper, so that a sufficient number of the metallic points
of the iron paint shall be exposed to allow of its (the paint) slow oxidation by
the action of the sea water. The object in thus inducing corrosion on the
paint, is that it shall prevent such an oxidated surface as shall render it
impossible for the fouling bodies to fasten themselves thereto, as in the case of
copper. This metallic iron paint is not intended to preserve surfaces of iron
from corrosion, but simply to prevent the same from fouling by reason of the
causes I have named; it is therefore to be laid on over such anti-corrosive
paint (such as the black paint herein described as may be previously on the
surface of the iron; moreover, it must obviously be renewed from time
to time.
Having, described the nature of this my Invention, and the manner in
which the same is carried into effect, I shall now state the claims I make in
respect thereof.
I hereby declare that I claim, in the first part, the use and application of the
spathose ore or proto-carbonate of iron (natural or artificial) for the
purpose
of a paint in mixture with oils or varnish, or any other media with which
paints are usually mixed.
I also claim as my Invention the black paint made from the oxide
which accrues from such treatment of the ore or its artificial equivalent,
as I have herein referred to and described.

page_text: I further claim as my Invention, in the second part, the metallic iron paint
herein described, but especially in regard to its application to prevent the
fouling of submerged surfaces by reason of its own corrosion.
In witness whereof, I, the said Thomas Spencer, have hereunto set my
hand and seal, this Thirtieth day of November, in the year of our
Lord One thousand eight hundred and sixty-five.
THOMAS SPENCER. (L.S.)