John Phin.

The workshop companion. A collection of useful and reliable recipes, rules, processes, methods, wrinkles, and practical hints for the household and the shop online

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the weather proves favorable, the wax becomes quite white.

Black-boards.

Various kinds of so-called " liquid slating " have been sold
for converting any smooth board or wall into a black-board
for school or other purposes. The following give very good
results; No. 1 is probably the best, but is somewhat expen-
sive.

1. Take alcohol (95 per cent.), 4 pints; shellac, 8 ounces;
lamp-black, 12 drachms; ultramarine blue, 20 drachms; pow-
dered rotten stone, 4 ounces; powdered pumice stone, G
ounces. First dissolve the shellac in the alcohol, then add
the other ingredients, finely powdered, and shake well. To
apply the slating, have the surface of the board smooth and
perfectly free from grease. Shake well the bottle containing
the preparation, pour out a small quantity only into an old
tea-cup, and apply it with a new flat varnish brush as rapidly
as possible. Keep the bottle well corked, and shake it up every
time before pouring out the liquid.

2. Instead of alcohol take a solution of borax in water; dis-
solve the shellac in this and color with lamp-black.

3. Dilute silicate of soda (water-glass) with an equal bulk
of water, and add sufficient lamp-black to color it. The lamp-
1 >lack should be ground with water and a little of the silicate
before being added to the rest of the liquid.

Brass.

Next to iron, brass is probably the most generally useful
metal, and as the varieties of this alloy are almost infinite, the
range of purposes to which it may be applied is very great.
The color of the alloy inclines to red when the proportion of
zinc is small, gradually changing to yellow, and ultimately
white, when the proportion of zinc is very large. The duc-
tility and malleability of the alloy increase with the quantity
of copper. Ordinary brass may be hammered, rolled into



THE WORKSHOP COMPANION. 19

sheets or drawn to wire while cold, provided it is occasionally
annealed by heating it' to a very low red heat. When worked
hot it crumbles to pieces under the hammer or between the
rolls. But the so-called yellow metal, or Muntz metal, an
alloy of 40 parts of zinc and 60 of copper, may be wrought
while red hot, rolled into sheets and forged into bolts. Brass
is not so readily oxidized as copper, being harder, tougher,
more easily fusible and more fluid when molten. It solidified
without becoming honey-combed, and hence is suited for
making all kinds of castings; while simply by the addition
of from 1 to 2 per cent, of lead, it is capable of being readily
worked on the lathe, and may then be filed without, as ifc
otherwise does, clogging the teeth of the file.

Finishing Brass. The article having been brought to
proper shape by means of the lathe, file, grindstone or other
means, the surface must be rendered smooth and free from
lumps, utters, or scratches. If finished in the lathe, emery
paper and oil may be used to smooth the surface, the final
polish being imparted by rouge. In all cases where brass or
other metals are polished by means of abrasive materials, great
care must be taken that all corners are left sharp and well-
defined, since nothing looks so badly as a corner which ought
to be square but which is worn and rounded in the process
of polishing.

In finishing brass work (and the same remark applies to
the polishing of other materials) great care must be taken to
avoid making any scratches which are deeper than the other
marks left by the material employed. Such scratches are
very difficult to remove by very fine files or by polishing
powders, and therefore, whenever the work shows such
scratches it is necessary to go back to the coarse file or scraper
and begin anew. (See articles on Polishing Metals and Polish-
ing Powders.}

Coloring and Varnishing Brass. To prevent the everyday
rusting of brass goods, the trade has long resorted to means
for protecting the surface from the action of the atmosphere,
the first plan of which i^ to force a change to take place.
Thus, if brass is left in damp sand, it acquires a beautiful
brown color, which, when polished with a dry brush, remains
permanent and requires no cleaning. It is also possible to
impart a green and light coating of verdigris on the surface
of the brass by means of dilute acids, allowed to dry spou-



grt ME WORKSHOP COMPANION.

taneously. 'The antique appearance thus given is very pleas-
ing, and more or less permanent. But it is not always pos-
sible to wait for goods so long as such processes require, and
hence more speedy methods became necessary, many of which
had to be further protected by a coat of varnish. Before
bronzing, however, all the requisite fitting is finished, and the
brass annealed, pickled in old or dilute nitric acid, till the
scales can be removed from the surface, scoured with sand
and water, and dried. Bronzing is then performed according
to the color desired; for although the word means a brown
color, being taken from the Italian " bronzino," signifying
burnt brown, yet in commercial language it includes all
colors. (See article on Bronzing. )

Browns of all shades are obtained by immersion in solu-
tions of nitrate or the perchloride of iron; the strength of
the solutions determining the depth of the color. Violets are
produced by dipping in a solution of chloride of antimony.
Chocolate is obtained by burning on the surface of the brass
moist red oxide of iron, and polishing with a very small
quantity of blacklead.

Olive-green results from making the surface black by means
of a solution of iron and arsenic in muriatic acid, the details
of the process being as follows:

Make the articles bright, then dip in aqua fortis, which
must be thoroughly rinsed off with clean water. Then make
the following mixture: Hydrochloric acid, 6 Ibs. ; sulphate of
iron, i Ib. ; white arsenic, Ib. Be careful to get all the in-
gredients pure. Let the articles lie in the mixture till black;
take out and dry in hot sawdust, polish with blacklead, and
lacquer with green lacquer composed of one part lac varnish,
four of turmeric, and one of gamboge.

A steel-gray color is deposited on brass from a dilute boil-
ing solution of chloride of arsenic; and a blue by careful
treatment with strong hyposulphite of soda.

Black is much used for optical brass work, and is obtained
by coating the brass with a solution of platinum, or with
chloride of gold mixed with nitrate of tin. The Japanese
bronze their brass by boiling it in a solution of sulphate of
copper, alum and verdigris.

Success in the art of bronzing greatly depends on circum-
stances, such as the temperature of the alloy or of the solu-
tion, the proportions of the metals used in forming the alloy,



THE WORKSHOP COMPANION. 21

and the quality of the materials. The moment at which to
withdraw the goods, the drying of them, and a hundred little
items of care and manipulation, require attention which ex-
perience alone can impart.

To avoid giving any artificial color to brass, and yet to pre-
serve it from becoming tarnished, it is usual to cover properly
cleaned brass with a varnish called " lacquer." To prepare
the brass for this, the goods, after being annealed, pickled,
scoured and washed, as already explained, are either dipped
for an instant in pure commercial nitrous acid, washed in
clean water, and dried in sawdust, or immersed in a mixture
of one part of nitric acid with four of water, till a white curd
covers the surface, at which moment the goods are withdrawn,
washed in clean water, and dried in sawdust. In the first
case the brass will be bright; in the latter, a dead flat which
is usually relieved by burnishing the prominent parts. Tlieri
the goods are dipped for an instant in commercial nitric acid,
and well washed in water containing some argol (to preserve
the color till lacquered), and dried in warm sawdust. So pre-
pared, the goods are conveyed to the lacquer room, where
they are heated on a hot plate and varnished.

The varnish used is one of spirit, consisting, in its simple
form, of one ounce of shellac dissolved in one pint of alcohol.
To this simple varnish are added such coloring substances as
red sanders, dragon's-blood, and annatto, for imparting rich-
ness of color. To lower the tone of color, turmeric, gamboge,
saffron, Cape aloes, and sandarac are used. The first group
reddens, the second yellows the varnish, while a mixture of
the two gives a pleasing orange. (See article on Lacquer.)

To Whiten Brass. Small articles of brass or copper may
be whitened by boiling them in a solution of f Ib. cream of
tartar, 2 quarts of water, and 1 Ib. grain tin or any pure tin
finely divided. The tin dissolves in the cream of tartar and
is again precipitated on the brass or copper.

Depositing Brass by Electricity. The first step is to t^or
oughly cleanse the articles, either by means of emery, or bv
laying them overnight in a weak bath of sulphuric acid.
They are then washed off with water, a weak soda solution,
and then immersed as the cathode of a bath consisting of 2
parts of sulphate of copper, 20 parts sulphate of zinc, and 45
parts cyanide of potassium, in 300 parts of water. The anode
should be two plates of zinc and copper of equal size. The



22 THE WORKSHOP COMPANION.

color of the resulting brass coating may be modified by
varying the depth of immersion of one or the other of the
plates. The galvanic current should be a strong one, and
the liberation of hydrogen bubbles on the object to bo
brassed should be plentiful. It is important, however, to
note that the objects should be first coppered to insure a
strong attachment of the brass coating.

Coating Brass with Copper. The following valuable process
for coating brass with copper, is given by Dr. C. Puscher:
Dissolve ten parts, by weight, of sulphate of copper, and five
of sal-ammoniac, in one hundred and fifty parts, by weight,
of water. Place the brass, well cleaned and free from fatty
matter on its surface, into this mixture ; leave it in it for a
minute; let the excess of liquid drain off first, and heat the
metal next over a charcoal fire, until the evolution of am-
moniacal vapors ceases, and the coppery film appears per-
fect. Wash with cold water and dry. The coating of cop-
per adheres firmly.

Cleaning Brass. Large articles of brass and copper which
have become very much soiled iray be cleaned by a mixture
of rotten-stone powder (or any hnarp polishing poAvder) with
a strong solution of oxalic acid. After being thoroughly
cleaned, the metal should be wiped oft' with a cloth moistened
with soda or potash, and a very light coating of oil should bo
applied to prevent the further corroding action of the acid.

A more powerful cleaning agent, because very corrosive,
is finely powdered bichromate of potash mixed with twico
its bulk of strong sulphuric acid and diluted (after standing
an hour or so) with an equal bulk of water. This will in-
stantly clean the dirtiest brass, but great care must be taken
in handling the liquid, as it is very corrosive.

Brass which has been lacquered should never be cleaned
with polishing powders or corrosive chemicals. Wiping
with a soft cloth is sufficient, and in some cases washing with
weak soap and water may be admissible. Dry the articles
thoroughly, taking care not to scratch them, and if, after
this, they show much sign of wear or corrosion, send them to
the lacquerer to be refinished.

Brazing and Soldering.

The term soldering is generally applied when fusible alloys
of lead and tin are employed for uniting metals. When hard



THE WOEKSHOP COMPANION. 23

Eleials, such as copper, brass or silver are used, tlie term
brazing (derived from brass) is more appropriate.

In uniting tin, copper, brass, etc., with any of the sofl
solders, a copper soldering-iron is generally used. This tool
and the manner of using it are too Veil known to need de-
scription. In many cases, however, the Work may be done
more neatly without the soldering-iron, by filing or turning
the joints so that they fit closely, moistening them with tho
soldering fluid described hereafter, placing a piece of Smooth
tin-foil between them, tying them together with binding wire,
and heating the whole in a lamp or tire till the tin-foil melts.
We have often joined pieces of brass in this way so that tho
joints were quite invisible. Indeed, with good soft solder
almost all work may be done over a spirit lamp or even a
candle, without the use of a soldering-iron.

More minute directions may be found in the Young Scien-
tist, Vol. I, page 56.

Advantage may be taken of the varying degrees of fusi-
bility of solders to make several joints in the same piece of
work. Thus, if the first joint has been made with fine tin-
ner's solder, there would be no danger of melting it in mak-
ing a joint near it with bismuth solder, composed of lead, 4 ;
tin, 4; and bismuth, 1; and the melting point of both is f^r
enough removed from that of a solder composed of lead, 2 ;
tin, 1; and bismuth, 2; to 1)6 in no danger of fusion during
the use of the latter. *

Soft solders do not inaKfe /nalleable joints. To join brass,
copper or iron so as to have the joint very strong and malle-
able, hard solder must be used. For this purpose equal
parts of silver and brass will be found excellent, though for
iron, copper, or very infusible brass, nothing is better than
silver coin rolled out thin, which may be done by any silver-
smith or dentist. This makes decidedly the toughest of all
joints, and as a little silver goes a long way, it is not very
expensive.

For most hard solders borax is the best flux. It dissolves
any oxides which may exist on the surface of the metal, and
protects the latter from the further action of the air, so that
the solder is enabled to come into actual contact with tho
surfaces which are to be joined. For soft solders the best
flux is a soldering fluid which may be prepared by saturating
hydrochloric acid (spirit of salt) with zinc. The addition of



24 THE WORKSHOP COMPANION,

i

a little sal ammoniac improves ID. It is said that a solution
of phosphoric acid in alcohol makes an excellent soldering
fluid, which has some advantages over chloride of zinc.

In using ordinary tinner's solder for uniting surfaces that
are already tinned such as tinned plate and tinned copper
resin is the best and cheapest flux, but when surfaces of iron,
brass or copper that have not been tinned are to be joined by
feoft solder, the soldering fluid is by far the most convenient.
Besin possesses this important advantage over soldering fluid,
that it does not induce subsequent corrosion of the article to
which it is applied. When acid fluxes have been applied to
anything that is liable to rust, it is necessary to see that they
are thoroughly washed off with clean warm water and tho
articles carefully and thoroughly dried. *

Oil and powdered resin mixed togethb. mane a good flux
for tinned articles. The mixture can be applied with a small
brush or a swab tied to the end of a stick.

In preparing solders, whether hard or soft, great care is
requisite to avoid two faults a want of uniformity in the
melted mass, and a change in the proportions of the con-
stituents by the loss of volatile or oxidable ingredients. Thus,
where copper, silver, and similar metals are to be mixed with
tin, zinc, etc. , it is necessary to molt the more infusible metal
first. When copper and zinc arc heated together, a large
portion of the zinc passes off i;i fumes. In preparing soft
solders, the material should be melted under tallow, to pre-
vent waste by oxidation ; and in melting hard solders, tho
same object is accomplished by covering them with a thick
layer of powdered charcoal.

To obtain hard solders of uniform composition, they are
generally granulated by pouring them into water through a
wet broom. Sometimes they are cast in solid masses and
reduced to powder by filing. Silver solders for jewelers aro
generally rolled into thin plates, and sometimes the soft;
solders, especially those that are very fusible, are rolled into
sheets and cut into narrow strips, which are very convenient
for small work that is to be heated by a lamp.

The following simple mode of making solder wire, which
is very handy for small w r ork, will be found useful. Take a
sheet of stiff writing or drawing paper, and roll it in a coni-
cal form, rather broad in comparison with its length. Mako
& ring of stiff wire, to hold ii in, attaching a suitable handle



THE WOKKSHOT* COMPANION. 25

to the ring. The point of the cone may first of all be cut off,
to leave an orifice of the size required. When filled with
molten solder it should be held above a pail of cold water;
and the stream of solder flowing from the cone will congeal
as it runs, and form the wire. If held a little higher, so that
the stream of solder breaks into drops, before striking the
water, it will form handy, elongated "tears" of metal; but,
by holding it still higher, each drop forms a thin concave
cup or shell, and, as each of these forms have their own
peculiar uses in business, many a mechanic will find this hint
very useful.

Hard solders are usually reduced to powder either by
granulation or filing, and then spread along the joints after
being mixed with borax, which has been fused and powdered.
It is not necessary that the grains of solder should be placed
between the pieces to be joined, as with the aid of the borax
they will " sweat " into the joint as soon as fusion takes place.
The same is true of soft solder applied with soldering fluid.
One of the essential requisites of success, hoAvever, is that
the surfaces be clean, bright, and free from all rust.

The best solder for platinum is fine gold. The joint is not
only very infusible, but it is not easily acted upon by common
agents. For German-silver joints, an excellent solder is
composed of equal parts of silver, brass, and zinc. The proper
flux is borax.

Bronzing.

Two distinct processes have had this name applied to them.
The first consists in staining brass work a dark brown or
bronze color and lacquering it; the second consists in par-
tially corroding the brass so as to give it that greenish hue
which is peculiar to ancient brass work. The first is gen-
erally applied to instruments and apparatus, the second to
articles of ornament.

Bronze for Brass Instruments. 1. The cheapest and sim-
plest is undoubtedly a light coat of plumbago or black lead.
After brushing the article with plumbago place it on a clear
fire till it is made too hot to be touched. Apply a plate
brush as soon as it ceases to be hot enough to burn tile brush.
A few strokes of the brush will produce a dark brown polish
approaching black, but entirely distinct from the well known
appearance of bl^ck lead. Lacquer with any desired tint,



26 THE WORKSHOP COMPANION.

2. Plate powder or rouge may be used instead of plum-
bago, and gives very beautiful effects.

3. Make the articles clean, bright and free from oil or
grease, then dip in aqua fortis, which must be thoroughly
rinsed off with clean warm water. Then make the following
mixture: Hydrochloric acid, 6 Ibs. ; sulphate of iron, lb.;
white arsenic, Ib. Be careful to get all the ingredients
pure. Let the articles lie in the mixture till black, take out
and dry in hot sawdust, polish with black lead, and lacquer
with green lacquer.

Antique Bronze. Dissolve 1 oz. sal-ammoniac, 3 oz. cream
tartar, and 6 oz. common salt in 1 pint of hot water; ad.d 2
oz. nitrate of copper dissolved in pint of water; mix well,
and, by means of a brush, apply it repeatedly to the article,
which should be placed in a damp situation.

Bronzing Liquid; Dissolve 10 parts of fuchsine and 5 parts
of aniline-purple in 100 parts of 95 per cent, alcohol on a
water bath; after solution has iaken place, add 5 parts of
benzoic acid, and keep the whole boiling for 5 or 10 minutes,
until the green color of the mixture has given place to a fine
light bronze-brown. This liquid may be applied to all
metals, as well as many othe* ,abstances, yields a very
brilliant coating, and dries quick 1 ::. It is applied with a
brush.

Bronzing Wood, Leather, Paper, etc.l. Dissolve gum lao
in four parts by volume of pure alcolipl, and then add bronze
or any other metal powder in the proportion of one part to
three parts of the solution, The surface to be covered must
be very smooth. In the case of wood, one or several coats of
Mention or Spanish white are given, u,nd the object is care-
fully polished. The mixture is painted on, and when a suf-
ficient number of coats have been given, the object is well
rubbed. A special advantage of this process is that the
coating obtained is not dull, but can be burnished,

2. Another method is to coat the object with copal or
other varnish, and when this has dried so far as to become
" tacky " flust bronze powder over it. After a few hours the
bronzed surface should Ipe burnished with a burnislier of
steel or agate.

Brpvvning Gun Barrels, (See



THE WOKKI? 1CP COMPANION. 27

Burns.

Those who work in red-hot metals, glass blowing, etc., are
sometimes apt to burn their fingers. It is well to know that
a solution of bicarbonate of soda (baking soda) promptly and
permanently relieves all pain. The points to be observed
are : 1. Bicarbonate of soda must be used; washing soda
and common soda are far too irritant to be applied if the
burn is serious. 2. The solution must be saturated. 3. The
/solution must be ice-cold.

A laboratory assistant in Philadelphia having severely
burned the inside of the last joint of his thumb while bend-
ing glass tubing, applied the solution of bicarbonate of soda,
and not only was the pain allayed, but the thumb could be
at once freely used without inconvenience.

Case-Hardening. (See Iron.)
Catgut.

This material is so valuable for many purposes that many
mechanics will find it useful to know how to make it, as they
can then provide themselves with any size and length that
may be needed. The process is quite simple. Take the en-
trails of sheep or other animals, remembering that fat animals
afford a very weak string, while those that are lean produce
a much tougher article, and thoroughly clean them from all
impurities, attached fat, etc. The animal should be newly
killed. Wash well in clean water and soak in soft water for
two days, or in winter for three days ; lay them on a table or
board and scrape them with a small plate of copper having a
semicircular, hole cut in it, the edges of which must be quite
smooth and not capable of cutting. After washing put them
into fresh water and then let them remain till the next day,
when they are to be well scraped. Let them soak again in
water for a night, and two or three hours before they are
taken out add to each gallon of water 2 oz. of potash. They
ought now to scrape quite clean from their inner mucous
coat, and will consequently be much smaller in dimensions
than at first. They may now be wiped dry, slightly twisted,
and passed through a hole in a piece of brass to equalize their
size; as they dry they are passed every two or three hours
through other holes, each smaller than the last. When dry
they will be round and well polished, and after being oiled
are fit for use.



23 THE WOBKSHOP COMPANION.

Cements.

General Rides. Some years ago the writer called attention*
to the fact that quite as much depends upon the manner in
which a cement is used as upon the cement itself. The best
cement that ever" was compounded would prove entirely
worthless if improperly applied. The following rules must
be vigorously adhered to if success would be secured:

1. Bring the cement into intimate contact with the sur-
faces to be united. This is best done by heating the pieces
to be joined in those cases where the cement is melted by
heat, as in using resin, shellac, marine glue, etc. Where
solutions are used, the cement must be well rubbed into the
surfaces either with a soft brush (as in the case of porcelain
or glass), or by rubbing the two surfaces together (as in mak-
ing a glue joint between two pieces of wood.)

2. As little cement \s possible should be allowed to remain
between the united surfaces. To secure this the cement
should be as liquid as possible (thoroughly melted if used
with heat), and the surfaces should be pressed closely into
contact (by screws, weights, wedges or cords) until the cement
has hardened.

Where the cement is a Solution (such as gum in water) and
the surfaces are very absorbent (such as porous paper), the
surfaces must be saturated with cement before they are brought
together.

4. Plenty of time should bo allowed for the cement to dry


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Online LibraryJohn PhinThe workshop companion. A collection of useful and reliable recipes, rules, processes, methods, wrinkles, and practical hints for the household and the shop → online text (page 2 of 16)