第 2 节
作者:
阎王 更新:2021-02-20 15:17 字数:9321
gold; and it is ready to use。 Clear the article to be plated from all dirt
and grease with whiting and a good brush; if there are cracks it may be
necessary to put the article in a solution of caustic potash。 At all
events every particle of dirt and grease must be removed; then suspend the
article in the cyanuret of gold solution; with a small strip of zinc cut
about the width of a common knitting needle; hooking the top over a stick
which will reach across the top of the vessel or bottle holding the
solution。 If the zinc is too large the deposit will be made so fast that
it will scale off。 The slower the plating goes on the better; and this is
arranged by the size if the zinc used。 When not using the plating fluid
keep it well corked and it is always ready to use; bearing in mind that it
is poison as arsenic; and must be put high out of the way of children; and
labelled poison; although you need have no fear using it; yet accidents
might arise it its nature were not known。
9。 ELECTRO SILVERING … USUAL METHOD
This is done every way the same as gold plating (using coin) except that
rock salt is used instead of the cyanuret of potassium to hold the silver
in solution for use; and when it is of the proper strength of salt it has
a thick curdy appearance; or you can add salt until the silver will
deposit on the article to be plated; which is all that is required。 No
hesitation need be felt in trying these receipts; as they are obtained
from a genuine source; and are in every day use。
10。 GOLD PLATING FLUID
Warm six ounces of pure rain water; and dissolve in it 2 ounces of cyanide
of potassium; then add a 1/4 ounce oxide of gold; the solution will at
first be yellowish; but will soon subside to white; then half fill a
bottle with whiting; fill it up with this solution and shake it well; you
may now take a piece of old cotton; wet it with the solution; rub it well
over brass; copper; &c。; and it is nicely washed with gold。
11。 SILVER PLATING FLUID
Dissolve one ounce of nitrate of silver; in crystal; in 12 ounces of soft
water; then dissolve in the water two ounces of cyanuret of potash; shake
the whole together and let it stand until it becomes clear。 Have ready
some 1/2 ounce vials; and fill them half full of whiting; then fill up the
bottles and it is ready for use。 The whiting does not increase the coating
powder … it only helps to clear the articles and save the silver fluid by
half filling the bottles。 The above quantity of materials will cost about
1。62c。; so that the fluid will be about 3 cents a bottle。 It is used in
the same way as the gold plating fluid。
12。 QUICKSILVER PLATING FLUID
Take of quicksilver one ounce; one ounce nitric acid; one ten cent piece;
rain water 1/2 pint to a pint; put the three first articles into a tumbler
together; let them stand until dissolved; occasionally stirring; then add
the water; and it is ready for use。 This is used in the same way as the
silver and gold plating fluid。
13。 TO GILD STEEL
Pour some of the ethereal solution of gold into a wine…glass; and dip into
it the blade of a new penknife; lancet; razor; &c。; withdraw the
instrument and allow the ether to evaporate; the blade will then be found
to be covered with a beautiful coat of gold; the blade may be moistened
with a clean rag or a small piece of very dry sponge dipped into the
ether; and the same effect will be produced。
14。 TO GILD COPPER; BRASS; &c。 … BY AN AMALGAM
The gilding of these inferior metals and alloys of them is effected by the
assistance of mercury with which the gold is amalgamated。 The mercury is
evaporated while the gold is fixed by the application of heat; the whole
is then burnished of left mat in the whole or in part; according as
required。
15。 GILDING GLASS AND PORCELAIN
Dissolve in boiling linseed oil an equal weight either of copal or amber;
and add as much oil of turpentine as will enable you to apply the compound
or size thus formed as thin as possible to the parts of the glass intended
to be gilt; the glass is to be placed in a stove till it is so warm as
almost to burn the fingers when handled。 At this temperature the size
becomes adhesive; and a piece of leaf gold applied in the usual way will
immediately stick。 Sweep off the superfluous portions of the leaf; and
when quite cold it may be burnished; taking care to interpose a piece of
india paper between the gold and the burnisher。 It sometimes happens when
the varnish is not very good that by repeated washing the gold wears off;
on this account the practice of burning it in is sometimes had recourse
to; for this purpose some gold powder is ground with borax; and in this
state applied to the clean surface of the glass by a camel hair pencil;
when quite dry the glass is put into a stove; heated to about the
temperature of an annealing oven; the gum burns off; and the borax; by
vitrifying; cements the gold with great firmness to the glass; after which
it may be burnished。
The gilding upon porcelain is in like manner fixed by heat and the use of
borax; and this kind of ware; being neither transparent nor liable to
soften; and thus to be injured in its form in a low red heat; is free from
the risk and injury which the finer and more fusible kinds of glass are
apt to sustain from such treatment。 Porcelain and other wares may be
platinized; silvered; tinned; or bronzed; in a similar manner。
16。 GILDING THE EDGES OF PAPER
The edges of the leaves of books and letter paper are gilded whilst in a
horizontal position in the bookbinder's press or some arrangement of the
same nature; by first applying a composition formed of four parts of
Armenian…bole and one of candied sugar; ground together with water to a
proper consistence; and laid on by a brush with the white of an egg。 This
coating; when nearly dry is smoothed be the burnisher; it is then slightly
moistened by a sponge dipped in clean water and squeezed in the hand; the
gold leaf is now taken up on a piece of cotton from the leathern cushion
and applied on the moistened surface; when dry it is to be burnished by
rubbing the burnisher over it repeatedly from end to end; taking care not
to wound the surface by the point。
17。 PROFESSOR WORTS' AMALGAM FOR SILVERING
This is the only means yet discovered for silvering iron directly; yet it
is not so lasting as some of the other processes。 Take quicksilver and the
metal potassium; equal parts by volume; put them together in a tumbler;
and if both metals be good there will be a brisk ebullition; which
continues until an amalgam of the two is formed; then add as much
quicksilver as there is of the amalgam; let it work till thoroughly mixed;
and it is ready for use。 This amalgam you may apply with a cloth to any
metal; even iron; though it be a rusty bar; and you have it neatly
silvered over。
18。 FOR COPPERING IRON
This is the latest method; and that now in use。 To a solution of sulphate
of copper; add a solution of ferrocyanide of pottasium; so long as a
precipitate continues to be formed。 This is allowed to settle; and the
clear liquor being decanted the vessel is filled with water; and when the
precipitate settles the liquor is again decanted; and continue to repeat
these washings until the sulphate of potash is washed quite out; this is
known by adding a little chloride of barium to a small quantity of the
washings; and when there is no white precipitate formed by the test; the
precipitate is sufficiently washed。 A solution of cyanide of potassium is
now added to this precipitate until it is dissolved; during which process
the solution becomes warm by the chemical re…action which takes place。 The
solution is filtered; and allowed to repose all night。 If the solution of
cyanide of potassium that is used is strong; the greater portion of the
ferrocyanide of potassium crystalises in the solution; and may be
collected and preserved for use again。 If the solution of cyanide of
potassium used to dissolve the precipitate is dilute; it will be necessary
to condense the liquor by evaporation to obtain the yellow prussiate in
crystals。 The remaining solution is the coppering solution; should it not
be convenient to separate the yellow prussiate by crystallization; the
presence of that salt in the solution does not deteriorate it nor
interfere with its power of depositing copper。
19。 PECULIARITIES IN WORKING CYANIDE OF COPPER SOLUTION
The true composition of the salts thus formed by copper and cyanide of
potassium has not yet been determined; but their relations to the battery
and electrolyzation are peculiar。 The solution must be worked at a heat
not less than from 150~ to 200~ Farenheit (that is not quite as hot a
boiling water; which is 212~ Farenheit。) All other solutions we have tried
follow the laws; that if the electricity is so strong as to cause gas to
be evolved at the electrode; the metal w