IMPROVEMENTS IN COATING AND ORNA- MENTING ZINC
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
HASTINGS GREENSTREET, of Albany Street, Mornington Crescent, in the County
of Middlesex, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Thirty-first day of
December (One thousand eight hundred and fifty-one), in the fifteenth year
of Her reign, did for Herself, Her heirs and successors, give and grant unto
me, the said Francis Hastings Greenstreet, my exors, adiñors, and assigns,
Her especial licence, full power, sole privilege and authority, that I, the said
Francis Hastings Greenstreet, my exors, adññors, and assigns, or such others
as I, the said Francis Hastings Greenstreet, my exors, adiñors, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, the Invention of "IMPROVEMENTS IN COATING AND ORNA-
MENTING ZINC ;" communicated to me from abroad; in which said Letters
Patent is contained a proviso, that I, the said Francis Hastings Greenstreet,
shall cause a particular description of the nature of the said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, to be inrolled in Her Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said

page_text: in part recited Letters Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Francis Hastings Greenstreet, do hereby that the nature of the said Inven-
tion, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, that is
to say:
These improvements consist in modes of coating, coloring, and ornament-
ing zinc, or bodies having a coating or surface of zinc, by the application to
the surface of acids, and acids combined with other substances which act
chemically upon zinc, either by themselves or when mixed together, or mixed
with pigments or other materials, and the coating or chemical compound thus
produced upon the zinc may either serve by itself for the protection or orna-
ment of the surface, or it may form the base or priming, over which painting
may be executed in the common manner with colors mixed with oil or
varnish ; and provision is made for finishing, preserving, and polishing the
coating formed on the zinc by applying over it suitable varnishes or polishes.
The zine should be as pure and as free from alloy as possible, and may be
either cast, rolled, or pressed. The choice of thickness of metal will in a great
measure depend upon the purpose to which the manufactured article is to be
applied; but it is to be observed that a very strong and thick chemical coating
cannot be produced on very thin zinc, such as would be injured by the corro-
sive action of the acids employed, and generally speaking, thick sheets of zinc
that have not been passed so many times between the rollers are more open in
their texture than the very thin sheets, and are consequently more favourably
acted upon by the substances applied.
The surface of the metal may be cleaned by well rubbing it with wood ashes,
or fine sand moistened with soft water, or with very dilute muriatic acid. It
is particularly to be observed that all greasiness and extraneous substances
must be removed from the surface of the zinc, and when the cleaning is
finished the face of the metal ought not to be touched with the hands. A
very smooth surface is not operated upon quite so favourably as a surface
rather rough, and especially in cases where a very strong coating is to be pro-
duced the surface of the zinc should be roughened; this may be done when the
metal is manufactured, or it may be done afterwards by scratching or scraping
the surface; and in some cases, that will be alluded to hereafter, it is advisable
to engrave lines at intervals over the surface.
Having cleaned the surface of the zinc, and rubbed it perfectly dry, place

page_text: the piece to be operated upon on a suitable stand, in such a manner that the
surface to be coated may be as nearly as possible in a horizontal position,
and then the coating or coloring may be executed in either of the following
ways:-
First, Sprinkling. Take thin sticks, fifteen or eighteen inches long, and
fasten to their ends small pieces of clean sponge; moisten the sponges with one
of the preparations or compounds (given hereafter), and then strike the sticks
with the sponge gently against another piece of wood held over the surface of
the zinc in such a manner that drops of the liquid compound may be thrown
out of the sponge uniformly over the surface of the zine; the size of the drops
may in a great measure be regulated by the quantity of liquid taken into the
sponge; and it is to be observed, that the drops should, particularly at first,
not be large or so close together as to run into one another, for the more
detached the drops are at first the greater will be the firmness and solidity of
the perfect coating produced by repetitions of the sprinkling, continued until
the surface of the zinc is sufficiently covered. In repeating the application of
the preparations, either in this or any other manner, it may be taken as a
general rule that the coating produced by the previous applications, when
properly dry, should be well washed with soft water, in order to remove any
particles that do not stick fast, and sponged almost dry, and then allowed to
get thoroughly dry in the air, but on no account may the drying be accelerated
by warming the zinc or holding it before a fire, because if that is done the
surface of the coating will have a tendency to become moist whenever the
weather is damp, although at first the coating may appear to be perfectly dry.
The washing and drying ought to be performed carefully; rubbing should as
nuch as possible be avoided, and only gentle sponging be the means employed.
If after successive sprinklings, when the surface of the metal is quite covered,
it is desired to produce a still thicker coating, it will be necessary to lay bare
the metal again at certain intervals over the surface. This is best done by
describing down to the metal with an engraving chisel a kind of network all
over the surface, composed of symmetrical cross lines about one-fourth or
three-cights of an inch apart, but the engraving must be carefully performed,
in order that the coating may be as little as possible disturbed. After this the
sprinkling may be again proceed with until the net work is filled up.
Second, Dabbing is done by striking the surface of the zinc with sponge
or hemp moistened with the preparations and fastened to the end of a stick;
by this means a dappled marble-like appearance may be given to the zinc,
but not a very thick coating.

page_text: Third, Spreading-In some cases the preparations may be spread or painted
over the surface of the zinc with a fine hair pencil, or a roll of soft leather or
cloth, as may be most desirable.
Fourth, Marbling.-Lay over the clean surface of the zinc a piece of thin
blotting paper, or any kind of thin unsized paper, and then apply the pre-
paration over the paper with a sponge or soft brush, in such a manner that the
liquid may soak through to the zinc beneath, or apply the preparation under-
neath the paper direct upon the surface of the zinc, which latter method is
generally to be preferred when pigments are used for the purpose of producing
a colored marbling. The gas formed by the action of the preparation upon
the zinc will raise the paper into irregular bladders, and the paper should bo
left untouched upon the zinc until the action has ceased, which will generally
be the case in two or three hours, it may then be lifted off, and the surface of
the zine underneath will have the appearance of veined marble, and after the
surface of the zinc has been allowed to get thoroughly dry in the air, it may
be washed with soft water and dried with a cloth. Different varieties of
marbling may be produced by using different kinds of paper or textile fabrics,
but generally speaking thin unsized paper answers best. Designs may be
transferred to the zinc but cutting out the pattern in paper, soaking the paper
with the preparation, and laying it carefully upon the zinc, or by laying the
paper dry upon the zine, and afterwards applying the preparation over it
with a fine brush; and upon the same principle, impressions of net lace and
many other fabrics may be transferred to the zine, as well as letters and
figures, &c. &c.
In the most essential points the foregoing instructions apyly to all the after-
mentioned preparations and substances, but there are exceptions which will be
pointed out under the heads of the several preparations, and to execute in tho
most perfect manner these different modes of applying the preparations, a
certain degree of practise is necessary, and it is only by attention that the
peculiar effects of the different substances can be fully understood. In order
to ensure the best results, the process should be carried on under a moderate
and uniform rate of temperature, and in a dry and well-ventilated building,
and it will be necessary artificially to dry the air in the operating room when
the weather is damp; and the articles operated upon should be left untouched
upon their stands until the action of the preparation upon the zinc has ceased,
and the coated surface should be placed as nearly as possible in a horizontal
position, so that the liquids applied may not run off on one side and create
blotches.

page_text: The following substances and preparations produce on the surface of the
zinc a coating of various colors and different degrees of strength and thickness,
but I do not confine myself to the use of only these specified materials, as
results varying in character may be obtained by many other acids and chemical
substances, but the following produce a suflicient variety of coatings for all
ordinary purposes, and owing to their comparatively inexpensive character,
they may on the score of economy be recommended:-
The
1. Preparation A.-Muriatic acid diluted in various proportions.
concentrated acid usually sold in trade must be diluted on an average with
half its quantity of distilled water. This proportion of water is, however, not
absolute, as the muriatic acid is not always of the same strength, I find that
a diluted acid of 1114 specific gravity answers well. The diluted muriatic
acid will produce on the surface of the zine a firm coating, and only acid
sufficiently diluted must be used. Concentrated muriatic acid will not produce
a firm coating, but a gelatinous solution which will be a long time in hardening
and then only a crust will be the result, which will easily peel off or dust away
from the zinc. There are also cases in which the commonly used dilution must
be varied in strength, as for instance, when certain pigments or other sub-
stances are to be added, for they do not all operate in the same proportion,
and, therefore, some require a more and some a less diluted acid than others;
thus practical trials with the different substances are absolutely necessary to
enable the operator to obtain the best results, and to produce on the surface
of the zinc a coating that is thoroughly adhesive to the metal, and that will
not peel off, and it may be accepted as a general rule that it is always
better to use acid rather too weak than too strong. The natural color of the
coating given to the zine by the application of diluted muriatic acid unmixed
with other substances is a light ash color. This preparation can be applied
to the zine in either of the ways explained above, but for giving a coating
sprinkling answers best, and it is particularly useful for mixing with and
diluting the other compositions.
2. Preparation B.-Chrone yellow, ground fine with soft water, and then
mixed with the dilute muriatic acid (Preparation A), until the whole forms a
liquid compound about the consistency of cream. This preparation will produco
a strong and quick drying coating of a yellowish-grey color. It is only suitable
for sprinkling and dabbing, and ought to be well stirred when used. It gives
the best result when fresh prepared.
3. Preparation C.-The pigment known in the trade as mountain or
Saxony green, of good quality, mixed by degrees with Preparation A into a
thin liquid compound, and stirred till the effervesence conses.
This prepara-

page_text: tion must be kept in a carefully stopped bottle, but not until the effervesence
has ceased, or the bottle will be liable to burst. This mixture acts quicker
than Preparation A, and produces a firm, strong casting of an iron-grey color,
tinged with green, more or less intense, according to the proportion of the
ingredients, and when used it must always be well stirred, in order that its
application may be a uniform one. The clear decantation of this preparation,
poured off without the sediment being stirred up, may also be used for pro-
ducing a thin coating or stain of a dark iron-black color, and which, by
repeated applications of the solution, may be much deepened. This prepara-
tion may be applied in either of the given methods, but sprinkling and dabbing
answers best. When this preparation is fresh made it operates most power-
fully, and especially when applied during fermentation, but such an application
is only suitable for inferior articles. When used for producing light and shade
effects with the pencil, this preparation may be applied in the following man-
ner Pour some of the decanted liquid upon a waste piece of zinc, and allow
it to form an effervesencing black solution; it may then be applied to the zine,
to be painted with a soft hair pencil; but this solution should only be used
for common work, as it is inferior to Preparation F, and it must not be laid on
too thick, or in many coats, or the coating will be apt to get loose.
4. Preparation D. White lead, ground fine with soft water, and then
mixed with diluted muriatic acid (Preparation A), till the whole forms a thin
liquid. It operates most favourably when fresh prepared, but only in a diluted
state, and gives a grey coating. This preparation should only be applied by
sprinkling, dabbing, or marbling, and it is especially useful in a diluted state,
as a medium for producing many kinds of light colors. In cases where
expense is not much consideration, Kreumitz white will be found preferable to
the common white lead.
5. Preparation E.-Flour of sulphur, ground fine, with soft water and
mixed with the diluted muriatic acid (Preparation A.) This is only suitable
for sprinkling in fine drops, and answers best when fresh prepared. The
colour it produces in the zinc is a yellowish white.
6. Preparation F. The butter of antimony of the shops, mixed in various
proportions with the before-mentioned preparations, operates intensely, but
only as long as it is in direct contact with the zine, and then it produces a
black coating, but it does not change the colouring otherwise executed, pro-
vided the surface of the zinc has been previously coated, and therefore this
preparation is the most suitable medium to use for chemical painting. It
may be applied to the zinc in either of the given modes, and produces a
fine black coating, superior to that of Preparation C. It is very useful for

page_text: shading, but to produce a good effect considerable skill and practice is neces-
sary, and it must be laid on with a very soft hair pencil. Moreover, it is not
generally advisable to apply this preparation direct to the zine that is to be
painted, but the solution should be used that has been allowed to effervesce
on a waste piece of zinc, as explained before under the head of Preparation C.
Preparation G. Butter of antimony, sufficiently diluted with distilled water,
may be used for drawing, printing, painting, and writing, but only direct on
the clean surface of the zinc. It produces a black colour with an effect like
Indian ink, but changes by admixture with pigments. The butter of antimony
should be diluted with water until it almost ceases to effervesce when applied
to the zinc. It may be laid on with a hair pencil or pen only moistened,
and the strokes at first should be given feebly in order that the after shading
may have a good effect.
Preparation H.-Butter of antimony mixed with spirits of turpentine and
preserved in a bottle. This mixture, when slightly rubbed on the clean and
roughened surface of the zine with a piece of wash leather or woollen cloth,
produces a black colour, or a colour of other tints when pigments are added;
and it must be well stirred whenever it is used, in order to prevent the sepa-
ration of the spirits of turpentine.
The foregoing instructions explain the methods of producing on the zinc
different kinds of coatings, varying in character and colour, and if the given
preparations be mixed together, or with other pigments than those described,
in different proportions, and applied to the zinc as before directed, a still
greater variety of coatings may be produced. And in choosing the prepara-
tions and colours, it is particularly necessary to consider whether they are to
be applied direct to the zine, or over a surface previously coated, for the effects
are often very different. In the latter case, generally speaking, the colors
undergo much less change than when applied direct to the zinc, especially if
very weak acid is used.
The Preparations C, F, and H (almost without regard to the admixture
with pigments) will produce only a dark colour whenever they come altogether
or only partly into direct contact with the zinc, provided their strength is
sufficient.
The Preparations A, B, D, E, and G may be mixed with pigments to produce,
even upon the bare zinc, an unlimited variety of coloured coatings, provided
the pigments used are such as will not be decomposed by acids of the requisite
degree of strength; the most suitable pigments are those of intense colour,
such as carmine, cochineal, vermillion, Prussian blue, gamboge, sap green,
&c., &c.; they must be ground fine with distilled water, and then mixed with

page_text: the preparations; and the compositions should always be well stirred before
being applied to the zinc. When chemical painting is to be executed over
a surface already coated, it is most advisable to mix the pigments with Pre-
paration A, together with a small quantity of Preparation G, and then to
dilute the composition until it has no visible action upon the zinc and does not
disturb the coating previously formed.
When a coating, as before directed, is once formed upon the zinc, painting
may be executed over it in the common manner with colours mixed either
with oils or varnishes, and it is by this method that bright colours are laid
on the chemically produced colours being usually rather dull. In cases
where a very thick coating is formed on the zine, by several repetitions of the
sprinkling process, and especially when the zinc is to be used for floorings,
it is advisable to finish the coating with several sprinklings of copal varnish,
which will run into the hollows and fill out the irregularities on the surface
of the chemically executed coating; and if mixed with pigments, the varnish
may serve at the same time to improve or heighten the effect of the colouring.
After this the surface may, if desirable, be ground and polished.
The most serviceable varnish for the coated zinc is wax and compounds of
wax; for not only is such a varnish easily kept in good order by rubbing, but it
effectually protects the zine and the coating on the zinc from injurious influ-
ences, and prevents any oxydation of the surface. The zinc should be mode-
rately warmed over a stove, and then the wax laid on in a melted state; when
the coating on the zine has absorbed as much of the wax as it will take up,
the superfluous wax should be wiped off, and after that the surface may be
polished by rubbing with a hard brush and woollen cloth. Wax dissolved in
spirits of turpentine or spirits of wine may be used instead of the melted wax,
in cases where there is an objection to warming the zine. If a polish brighter
than that given by the wax is required, any of the ordinary varnishes may be
used; but, as before stated, wax is to be preferred for durability.
It is to be understood that I make no claim to the use of a solution of the
nitrate or sulphate of copper, such as is now employed for writing on pieces
of zinc used as labels, but what I claim is, the mode of coating and ornament-
ing zine or zinced surfaces by compounds acting chemically upon the surface,
as herein-before described.
In witness whereof, I, the said Francis Hastings Greenstreet, have
hereunto set my hand and seal, this Third day of June, in the
vear of our Lord, One thousand eight hundred and fifty-two.
FRANCIS HASTINGS (L.s.) GREENSTREET.

page_text: AND BE IT REMEMBERED, that on the Third day of June, in the
year of our Lord 1852, the aforesaid Francis Hastings Greenstreet came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Enrolled the Thirtieth day of June, in the year of our Lord One thou-
sand eight hundred and fifty-two.