IMPROVEMENTS IN PROTECTING SUBMERGED STRUCTURES OF IRON OR STEEL FROM CORROSION AND FOULING, AND IN COMPOSITIONS THEREFOR, PARTLY APPLICABLE FOR PROTECTING WOODEN STRUCTURES C PROVISIONAL SPECIFICATION
Year: 1883

page_text: :
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LETTERS PATENT to Farnham Maxwell Lyte of Cotford, Oakhill Road, Putney
in the county of Surrey for an Invention of IMPROVEMENTS IN PROTECTING
SUBMERGED STRUCTURES OF IRON OR STEEL FROM CORROSION AND FOULING,
AND IN COMPOSITIONS THEREFOR, PARTLY APPLICABLE FOR PROTECTING
WOODEN STRUCTURES
C
PROVISIONAL SPECIFICATION left by the said Farnham Maxwell Lyte at
the Office of the Commissioners of Patents on the 14th November 1883.
FARNHAM MAXWELL LYTE of Cotford, Oakhill Road Putney in the County of
Surrey "IMPROVEMENTS IN PROTECTING SUBMERGED STRUCTURES OF IRON OR
STEEL FROM CORROSION AND FOULING AND IN COMPOSITIONS THEREFOR, PARTLY.
APPLICABLE, FOR PROTECTING WOODEN STRUCTURES."
3.
When iron is immersed in water, particularly sea water, it is especially liable to
injury by (1) The corrosion of the metal by oxidation, and (2) The fouling of its
surface by the growth of weeds, barnacles, &°, and by dirt. :
The first cause of injury is easily obviated by protecting the surface of the iron
by paint; the second cause is however not so easily disposed of.
Several anti-fouling compositions are already known which are applicable to
wooden surfaces. When however they are applied to iron, the electro positive iron
reduces the more electro negative metals they contain and the paint detaches or
becomes destroyed and decomposed.
To obviate this I propose to first protect iron and steel from corrosion by the
application thereto of an inert non conducting or imperfectly conducting paint, or
one having for a basis a metallic oxide electro positive to iron and steel or
sufficiently electro positive not to be reduced thereby, and secondly to apply upon
such anti-corrosive paint a paint having anti-fouling or poisonous qualities to the.
weeds, barnacles & the mode of preparing and applying these paints being as
follows: A paint is made by mixing drying oil, with or without turps, by
preference with oxide of zinc or hydrated oxide of zinc, or with powdered glass or
porcelain or pounded burnt clay, finely divided silica, alumina, magnesia, or some
substance which is inert or non-conducting, or the oxide of a metal which is electro
ID 77

page_text: "
positive to iron, adding to one or either of these paints if necessary a slight
percentage (say 10%) of peroxide of lead, or the requisite quantity of red lead or
some compound to promote drying. As the lead is only added to promote drying,
its addition or the proportion in which it is added is not essential.
I may also use for the basis of this paint sulphate of baryta (fixed white) or
even iron oxide paint, or sulphide of zinc or the so-called silicate paint and plain
drying oil or drying oil in which a powdered resin is suspended may also be employed
and the paint may be made up with varnish as well as with drying oil. Never-
theless the oxide of zinc mixed with drying oil as recommended above appears to
answer as well or better than any.
With one of these paints which are inert to iron and steel the surface of the
structure (as free as possible from previous corrosion) is to be coated by one or
more first coats. The iron being thus protected and isolated, a coat of poisonous
paint is applied upon this protective coating. I would here point out that the
application of an inert or non conducting paint. as a first coating to the iron or
steel structure, furnishes a dense impenetrable covering effectually insulating the
iron or steel structure from the electro negative metals contained in the outer
coating of anti-fouling paint and thereby preventing the rapid destruction of the
latter as has heretofore been the case. I would also call particular attention to
the fact in connection with the above mentioned effects, that I use as a first coating
an inert non-conducting or electro positive paint in contra distinction to a spirit
varnish or other medium which is both expensive and will not answer well the
purposes desired.
This first coat or layer is rendered anti-fouling or poisonous to weeds,
barnacles &, by the application thereto of a paint having a basis of oxide of zinc,
white lead or any of the usual compounds to which is added a quantity sufficient
to be poisonous to the growths, of Scheeles or Schweinfurt green (arsenite of
copper, or the compound of the basic acetate and arsenite of copper) or one of the
oxides of copper or the basic acetate of copper by itself or one of the insoluble
salts of copper and if necessary the requisite quantity of peroxide of lead or some
lead compound to promote drying. The poisonous coating or paint may also be
composed of arsenite of zinc or of antimony or of some other metal made by
adding arsenite of soda (produced by boiling arsenious acid in a solution of soda
until it will dissolve no more) to a solution of a zinc or of an antimony.or other
metallic salt, say to the chloride or otherwise.
The anti-fouling coating may also consist of a paint containing the arsenite of
peroxide of iron or the arsenite of lead. The arsenates of copper, iron zinc, lead,
antimony, or other metals may also be used. Any ordinary antifouling paint may
also be used although those I have specified are preferred.
It will be observed that this Invention, so far as it relates to iron or steel
surfaces, depends upon: 1st The protection of the iron or steel by means of a first
coating of an inert nonconducting or electro positive paint having for its basis
oxide of zinc or some non-conducting substance, or the oxide of some metal electro
positive to iron. 2nd Applying thereupon a paint containing arsenic or copper in
one of their forms as arsenious or arsenic acid chemically combined (not mixed)
with certain other metals or any already known antifouling paints in order to
poison growth.
I would have it understood that the above mentioned paint having for its basis
oxide of zinc or a salt of zinc or oxide of antimony, or a salt of antimony.
chemically combined with arsenious acid or arsenite of antimony is also applicable
for protecting wooden surfaces without the employment of the first coating of
paint.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Farnham Maxwell Lyte in the Patent Office on the 14th May
✓ 1884.
FARNHAM MAXWELL-LYTE of Cotford, Oakhill Road, Putney, in the County of
Surrey. "IMPROVEMENTS IN PROTECTING SUBMERGED STRUCTURES OF IRON OR
STEEL FROM CORROSION AND FOULING AND IN COMPOSITIONS THEREFOR, PARTLY
APPLICABLE FOR PROTECTING WOODEN STRUCTURES,”
It is well known that submerged iron structures are especially liable to injury
by (1.) Corrosion of the metal by oxidation, and (2) Fouling by the growth of
weeds, barnacles, &c. The first cause of injury is easily obviated by painting the
surface of the structure, but the second cause is not so easily disposed of, because,
notwithstanding that there are several anti-fouling compositions which are applicable
to wooden surfaces, when these are applied to iron, the electro-positive iron reduces
the more electro-negative metals contained in the compositions, and a galvanic
action being thus set up, the iron becomes corroded and the paint detaches or
becomes destroyed and decomposed.
To obviate this I first protect iron or steel structures by the application thereto
of a sufficient thickness of a paint having for its essential basis a metallic oxide
electro-positive to iron and steel (or sufficiently electro-positive not to be reduced
thereby) or by the application of an inert, nonconducting, or imperfectly conducting
paint, and then apply upon such anti-corrosive paint, a paint having anti-fouling
qualities or qualities poisonous to weeds, barnacles, &, the mode of preparing and
applying these paints being as follows:
A paint is made by mixing drying oil (with or without turps, benzine, or
benzoline) with, by preference, oxide of zinc or hydrated oxide of zinc which is
electro-positive to iron and steel, or with some metallic oxide the metal of which is
sufficiently electro-positive to iron and steel not to be reduced thereby, or with
powdered glass or porcelain or pounded burnt clay, finely divided silica, alumina,
magnesia, or some other substance which is inert or non-conducting (such as
powdered coal or anthracite, coke, or graphite) adding to either of these paints (if
necessary) a alight percentage (say 10%) of peroxide of lead or the requisite
quantity of red lead, or still better manganese driers or some compound to promote
drying. I may also use as the basis of this paint sulphate of baryta (fixed white)
or the so called silicate paint, although the oxide of zinc appears to answer as well,
if not better, than any. The lead or driers are only added to promote drying, and
as the addition of any lead compound is always more or less injurious, it is advisable
that only the smallest necessary amount of this drier should be employed, such
proportion not in any case exceeding 10%.
With one of these paints the surface of the structure (as free as possible from
previous corrosion and dirt) is to be coated by one or more first coats, and the iron
being thus protected and isolated, I apply upon this first coat or layer when
sufficiently dry, any suitable anti-fouling paint, but preferably one which has a
basis of oxide of zinc, white or red lead, or any of the usual compounds, and
contains a quantity. (sufficient to be poisonous to the growths) of Schweinfurt green
(ie. the compound of the basic acetate of copper and arsenious acid) or of the basic
acetate of copper by itself, together with, if necessary, the requisite quantity of
peroxide of lead or some compound to promote drying; or the poisonous qualities
may be imparted to the paint by adding to the above mentioned or any suitable
basis (in lieu of or in addition to the poisonous ingredients above mentioned)
arsenite of antimony made by adding arsenite of soda (produced by boiling

page_text: arsenious acid in a solution of soda until it will dissolve no more) to a solution of
an antimony salt, say to the chloride; or the arsenate of antimony may be used.
No proportions can very well be given for the ingredients considered separately,
but a mixture of equal parts of Schweinfurt green and arsenite of antimony, and
white or red lead made up into a paint with drying oil answers very well. I do
not, however, confine myself to such a mixture nor to those particular proportions.
It will be observed that this Invention so far as it relates to iron or steel surfaces
depends upon :-
[
5
1 The protection of the iron or steel by means of a first coating of an inert,
isolating, non-conducting or. electro-positive paint, and 2nd The application, on
this first coat, of a paint containing arsenic combined with the basic acetate of
copper or antimony or the basic acetate of copper by itself.
The above mentioned paint having for its basis oxide of zinc and containing.
antimony chemically combined with arsenious acid, is also applicable for protecting
wooden surfaces without the employment of the first coating.
I am aware that it is not new to coat ships and other submerged structures of
iron and steel with a first coat of ordinary paint to serve as a priming on which to
apply the antifouling paint; and I am further aware that oxide of zinc and some of
the other substances above mentioned have been used as ingredients of such
priming or first coat. The oxide of zinc or the other substances have, however,
constituted merely accessory or minor ingredients in such priming or first coat,
whereas according to my Invention I practically coat the structure with a dense
layer of oxide of zinc or other sufficiently electro-positive metallic oxide or inert or
non-conducting substance, so that the anti-fouling paint subsequently applied is
completely isolated from the surface of the iron or steel. In other words the oxide-
of zinc or other electro-positive, inert, or non-conducting substances constitute the
essential basis of this paint, the other ingredients of said paint serving merely as
vehicle and drier.
In order to lay greater stress on the importance of my Invention, I would
observe that if the principal ingredient of the first or under coat of paint, were,
for example, one of the oxides of mercury, of copper, of antimony or of arsenic, or
compounds of either of these metals, the paint would be useless as a protection, on
account of these compounds being electro-negative and consequently liable to be
acted upon by the iron. Oxide of lead, or one of the lead compounds, being also
slightly electro-negative (but less so) might act efficaciously at first, but after a
time would become useless. Oxide of iron, and its insoluble compounds would be
better, but oxide of zinc, oxide of magnesium (magnesia) oxide of aluminum
(alumina) oxide of calcium (lime) or any of their insoluble compounds will last
indefinitely as they are all electro-positive to iron
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is:
1st The use, substantially as herein described, of two successive and differently
constituted coats of paint for the purpose of protecting surfaces of iron or steel, the
first coat consisting of a paint having for its basis the oxide of any metal electro-
positive to iron or steel, or sufficiently electro-positive to iron or steel so as not to
be reduced thereby, and the second coat consisting of paint having anti-fouling or
poisonous qualities.
2nd In the method of protecting submerged structures of iron or steel from
corrosion and fouling herein before described, the use of two successive and differently
constituted coats of paint, of which the first is electro-positive to iron or steel and
the second has antifouling or poisonous qualities, the first coat consisting of a paint
composed essentially. of oxide of zinc or hydrated oxide of zinc for the purpose
specified, and being employed in combination with a second coat of anti-fouling
paint.
i
3rd In the method of protecting submerged structures of iron or steel from
corrosion and fouling hereinbefore described, the use of two successive and

page_text: differently constituted coats of paints, of which the first is inert or non-conducting
and the second has antifouling or poisonous properties, the first coat consisting of a
paint having for its basis fixed white (sulphate of baryta) or silicate paint or
powdered glass or porcelain or pounded burnt clay or finely divided silica, alumina,
magnesia, anthracite, graphite or coke, and being employed for the purpose specified,
in combination with a second coat of anti-fouling paint
4th The manufacture, and employment, as a new product, of an anti-fouling
paint for submerged structures of iron and steel having a basis of oxide of zinc,
white or red lead or any of the usual compounds and containing a compound of
basic acetate of copper combined with arsenious acid (the aceto-arsenite of copper,
Schweinfurt green) or basic acetate of copper alone, or the arsenite or arsenate of
antimony alone or mixed with either of the above poisonous ingredients, whether
such paint be applied on an inert non-conducting or electro positive covering as
specified, or not.
5th The manufacture and employment, as a new product, of an anti-fouling paint
having a basis of oxide of zinc, white or red lead or any of the usual compounds,
and containing antimony chemically combined with arsenious acid, substantially as
specified
In witness whereof, I the said Farnham Maxwell Lyte, have hereunto set my
hand and seal this Thirteenth day of May A.D. 1884.
MAYWELL Gol TVTD