Improvements in Preparing the Surface of Iron and Steel in the form of Flat or Corrugated Sheets, Hoops, Wrought or Cast Plates, Bars, or Manufactured Articles, for the Purpose of Coating it, and in Coating it with Waterproof Material for the Prevention of Oxidation or Rust.
Year: 1889

page_text: Date of Application, 17th Dec., 1889-Accepted, 18th Jan., 1890
TOMPLETE SPECIFICATION,
Improvements in Preparing the Surface of Iron and Steel in the
form of Flat or Corrugated Sheets, Hoops, Wrought or Cast Plates,
Bars, or Manufactured Articles, for the Purpose of Coating it,
and in Coating it with Waterproof Material for the Prevention
of Oxidation or Rust.
1 ROBERT CHARLES JAY of 41, Saint Luke's Road, Westbourne Park, in the
County of Middlesex, Barrister-at-Law 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 object of this Invention is to produce a suitable surface on the iron or steel so as
to give the coating a firm hold and to coat iron and steel in the form of flat or
corrugated sheets, hoops, wrought or cast plates, bars, or manufactured articles,
with a waterproof material that will prevent oxidation or rust in such manner that the
coating will adhere firmly and will not easily chip or fly off as also to produce a good
and serviceable coating at a lower cost than that of galvanizing or coating iron with
spelter.
In order to carry out my Invention I expose the iron or steel to the moisture of the
atmosphere for a sufficient length of time to bring the scale off and form a coat of
oxide or rust sufficient to eat into the surface of the metal but a thinner coat of rust
may be employed-As this method of rusting the surface must necessarily occupy
some length of time I prefer placing the iron or steel in a bath of acid diluted with
water to bring off the scale and for this purpose I employ muriatic acid in the
proportion of one part of acid to five parts of water-These proportions may be varied
with the requirements of the work and the acid and water may be heated in order to
produce a more rapid action-After the iron. or steel has been in the bath sufficiently
long to bring off the scale, which may require a little assistance in the way of scraping,
I take it out and wash the acid off with water or by dipping it into a bath containing
water and then I expose it to the action of the atmosphere until a sufficient coat of
rust is formed and I assist the process of rusting by moistening the surface of the
iron or steel from time to time with water-The grey film on the iron or steel after
placing in the acid solution may be left on or it may be cleaned off and a scraper or
scratch brush with the addition of water may be used for this purpose and I find the
iron or steel will rust more rapidly when alternately moistened as before described
and dried in a warm atmosphere until a thin coating of rust has been formed when it
may be exposed to the atmosphere as before mentioned.
When the coating of rust is formed I thoroughly dry the iron or steel in an oven
heated to a temperature not sufficiently hot to destroy the coating of rust-It is not
necessary to obtain an exact temperature but I prefer to make the metal as hot as the
hand can well bear as the coating material then combines more thoroughly with the
rust which becomes saturated, thereby bringing the coating material into contact with
the iron or steel itself, thus preventing further oxidation.
The steel or iron having attained the necessary temperature I then coat it with
ordinary gas tar, pitch or a mixture of the two the proportions whereof may vary
with the requirements of the work.
Where pitch is employed I find an addition of treacle or molasses may be employed
with advantage to temper the pitch and render it less brittle-The treacle or molasses
should be thoroughly mixed with hot pitch and this can be more completely carried
out by mixing small quantities at a time.
This coating material may be applied to the iron or steel after the rusting process
or it may be applied to it in its ordinary state without removing the scale as its
adhesive nennertier FA
enoh es to proment it from readily chinning or Axing off-
"

page_text: I mix one part of treacle or molasses with fivo parts of pitch but more treacle or
molasses may be added if it is desired to make the coating more pliable and I employ
treacle or inolasses mixed with gas tar in like manner and in the same proportions-
I also in some cases employ boiled oil or linseed oil as the coating material and when
I require the coating to be coloured I employ colours or paint mixed in the ordinary
manner with boiled oil or driers or both and for some work 1 employ Aspinall's
enamel either as a first coating which may be re-coated or as a finishing coat after the
tar, pitch or other coating has been applied-Again in some instances I mix dry
colours or colours mixed with boiled oil or driers or both into a thick paint with tar
or pitch either seperately or combined or mixed with treacle or molasses as before
mentioned, for which purpose the pitch must be heated and it is also advisable to heat
tar when used seperately or when either are combined with treacle or molasses so as
to make the colours mix more freely-Colour must be added until the desired shade is
obtained.
The tar or pitch either seperately or combined with treacle or molasses will when
mixed with the colours produce darker colours which will be found to differ con-
siderably from the colours originally employed.
I apply all or any of the before mentioned coating materials to the surface of the
iron or steel after it has been oxidized or rusted as before described by means of a
brush or preferably by dipping it into a bath containing the coating material which
may be cold if sufficiently fluid or it may be heated for which purpose I pass steam
through tubes placed round or under the bath or both so that when combustible coating
material is employed the possibility of its taking fire may be avoided.
The iron or steel is only required to remain in the bath a few minutes and I then
submit it to a drying heat in an oven commencing at a low temperature so as not to
make the coating run and gradually raise the heat-The temperature to which the
drying heat may be raised must necessarily vary with the coating material employed
but where possible it should be gradually raised to about 150° Fahrenheit so as to be
able to bear the heat of the sun and kept there until testing samples show that the
coating is sufficiently set not to run and in cases where the articles are to stand hot
water such as hot water cylinders and tanks the temperature must be raised to over
212° Fahrenheit in like manner.
When the iron or steel has been submitted to the necessary drying temperature
for a sufficient time I remove it from the oven and allow it to cool and if required it may
be re-dipped and dried again one or more times so as to give it a thicker coating in which
case I carry the drying of the first coat to a higher point and lower the temperature of
the coating bath as also of the iron or steel as much as possible, without sacrificing
the fluidity of the coating material, so as to avoid dissolving the first coat.
When I employ paint or Aspinall's enamel as a finishing coat on tar or pitch I
dry the tar or pitch as before described and apply the paint or enamel cold after
which I slowly dry it in an oven at a low temperature so as not to dissolve the coating
of tar or pitch and cause discolouration.
When articles are required to be manufactured quickly I make them up out of
sheets or plates or such other iron or steel materials as may be necessary that have
been previously rusted as before described and which I take from stock but in other
cases I manufacture the articles in the first instance and then put them through the
rusting process.
In the case of corrugated iron and steel sheets I rust and coat them after corrugating
and in all cases 1 complete the manufacture of the article as far as possible before
coating it.
A further part of my Invention consists in cleaning off the scale of iron or steel
by placing it in a bath of muriatic acid and water as before described and retaining
it there until the surface becomes coated with a grey film. I then wash the iron or
steel in water in order to get rid of the acid and for some purposes I brighten the
surface by scraping or by means of an iron or steel wire scratch-brush, but I prefer
leaving the grey film on where possible, and I then dry the iron or steel in an oven
and coat it with waterproof material as before described.

page_text: Although I prefer to employ muriatic acid in preparing the surface of the iron or
steel as hereinbefore described other acids may be used to dissolve or clean off the
scale such as sulphuric acid or oil of vitriol.
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―
Firstly. The Improvements in preparing the surface of iron and steel, in the form
of flat or corrugated sheets, hoops, wrought or cast plates, bars or manufactured
articles, substantially and for the purpose or purposes hereinbefore described.
Secondly. The Improvements in coating iron and steel, in the form of flat or
corrugated sheets, hoops, wrought or cast plates, bars, or manufactured articles,
substantially and for the purpose or purposes herein before described.
Thirdly Preparing the surface of iron and steel in the form of flat or corrugated
sheets, hoops, wrought or cast plates, bars, or manufactured articles, by oxidizing or
rusting, substantially and for the purpose or purposes hereinbefore described.
Fourthly. Preparing the surface of iron and steel, in the form of flat or
corrugated sheets, hoops, wrought or cast plates, bars, or manufactured articles,
by scaling or cleaning off the scale, substantially and for the purpose or purposes
hereinbefore described.
Fifthly Preparing the surface of iron and steel, in the form of flat or corrugated
sheets, hoops, wrought or cast plates, bars, or manufactured articlos, by producing
a film, substantially and for the purpose or purposes herein before described.
Sixthly. The coating of iron and steel, in the form of flat or corrugated sheets,
hoops, wrought or cast plates, bars, or manufactured articles, with tar, pitch, oil, or
paint, after the surface has been prepared as herein before described, substantially and
for the purpose or purposes hereinbefore described.
Seventhly. The coating of iron and steel, in the form of flat or corrugated sheets,
hoops, wrought or cast plates, bars, or manufactured articles with a composition of
tar or pitch and paint or colour, after the surface has been prepared as herein-
before described, substantially and for the purpose or purposes hereinbefore
described.
Eighthly. The coating of iron and steel, in the form of flat or corrugated sheets,
hoops, wrought or cast platus, bars, or manufactured articles, with a composition of
tar or pitch and treacle or molasses, either seperately or with colour or paint,
before or after the surface has been prepared as herein before described, substantially
and for the purpose or purposes hereinbefore described.
Ninthly. The coating of iron and steel, in the form of flat or corrugated sheets,
hoops, wrought or cast plates, bars, or manufactured articles, after a film has been
produced on the surface as herein before described, substantially and for the purpose
or purposes herein before described.
Tenthly. The recoating of iron and steel in the form of flat or corrugated sheets,
hoops, wrought or cast plates, bars or inanufactured articles with waterproof material
in the nature of tar, pitch, paint or Aspinall's enamel as herein before described.
substantially and for the purpose or purposes hereinbefore described.
Dated this 17th dow of December 1880