SOME TYPICAL PLANTS.
An interesting Airostyle plant is shown in Figs. 95, 96 and 101, and is
arranged for 16 operators to deal mainly with bronze lacquers, hence
the somewhat simple arrangement with no provision for adjustment of
pressures at each hood.
[Illustration: Fig. 97.--SIDE ELEVATION OF PLANT FOR 12 OPERATORS.]
It will be noted that the ventilator employed is of important size; the
compressor delivering air to the plant is stationed in the basement.
The views of the plant are excellent, and serve to remove the erroneous
impression that such a plant cannot be conveniently and economically
arranged, both as regards floor space occupied and the provision of
adequate gangways on all sides.
Another interesting Airostyle plant is shown in Figs. 84, 85 and 86,
and was installed for japanning gas fires, radiators, gas cookers,
etc. An item worthy of note in this plant is the patented hot air
apparatus installed for warming the japan and for also heating the
sprayer and flexible tube conveying the japan to the sprayer; it is
clearly seen in the centre of the two hoods. The large hood is mainly
used for radiators, which are wheeled on to the large ball-bearing
turn-table, shown white for the purpose of a clearer view, but when
not so used a table is wheeled into position and two operators are
accommodated for smaller work.
[Illustration: Fig. 98.--PART END ELEVATION OF PLANT FOR 12 OPERATORS.]
The power unit, consisting of electric drive and suitable overhead
countershaft, together with the compressor and ball-bearing fan, is
shown in Fig. 100, and is directly outside the japanning shop.
This plant was installed for the Davis Gas Stove Company, Luton, and
has been in operation for several years.
The compressor shown in Fig 98 also delivers air to the gas cooker
department for two or three operators, and to the porcelain enamelling
department for six or seven operators, but as the same practice is
adopted as is shown in the photos here reproduced, no useful purpose
will be served in describing them in detail.
Undoubtedly one of the most important plants in the country, and one
producing the highest finish, is installed at Messrs. Joseph Lucas,
Ltd., Birmingham, and the photographs reproduced here are by their
kind permission. The author was granted the privilege of inspecting
the plant fully, and proposes to enlarge upon its arrangement and
capacities for saving of labour, etc.
[Illustration: Fig. 99.--PLAN OF FIGS. 96 AND 97.]
The whole of the work was carried out by Messrs. The Airostyle and
Lithos, Ltd., and it must be admitted that the plants are so arranged
as to admit of rapid handling of the work, and the subsequent stoving
of the articles is just as conveniently provided for.
Two distinct plants are in use at the moment with a separate steel
plate central draught fan and a water-cooled air compressor (the type
of fan and air compressor employed is shown elsewhere in the book, see
Figs. 71 and 79).
[Illustration: Fig. 100.--AIROSTYLE PLANT POWER UNIT, COMPRESSOR, MOTOR
FAN ETC., INSTALLED FOR THE DAVIS GAS STOVE CO., LTD., LUTON.]
On referring to the drawings Figs. 97, 98 and 99, showing respectively
an elevation, end view and plan of one of the plants, it will be seen
that the plant is divided up into two bays, each accommodating six
operators, so that, in all, twenty-four operators are provided for in
the two plants and were actually seen at work.
It will at once be noticed that ample space between the bays is
provided, and this is most essential in order to give sufficient room
for the racks which are wheeled into place behind each operator. These
racks are readily seen in the photographs, Figs. 103 and 106, and can
also be distinguished in Fig. 104.
The japanning shop in which the plants are installed is of large
dimensions, 250 feet long by 48 feet wide, and is extremely light and
airy, but, owing to the fact that the roof-lights are now painted
over (by Government regulations), the shop at present appears to
disadvantage, and the photographs consequently suffer.
The photographs, nevertheless, show very clearly what an immense amount
of work can be daily handled, but, notwithstanding this, the writer
was assured that there were still numbers of brush hands in the shop.
This was primarily due to the fact that full arrangements for spraying
are not yet completed (12 more operators are being provided for), and,
secondly, to the fact that certain work needing a large amount of
masking can be almost as readily brushed, and this class of work finds
employment for brush hands. Messrs. Lucas, Ltd., admit that there is a
wastage of japan, but maintain that a heavier and much more even coat
is applied with a superior finish to brush work, and that there is an
enormous gain in time of about 4 to 1 over brushing.
They state, also, that an indirect gain is obtained in the economical
working of the stoves, for these are filled far more quickly, and,
consequently, the daily output per stove is correspondingly increased.
A striking proof of the saving is their statement that if they had
not the system of spraying at work, it would have meant 200 hands in
the japanning department, whereas they now employed only 90, and a
considerable number of these were engaged upon brush work, so that if
only the whole of the work could have been handled with the spray, then
the number of hands necessary would have been even less than 90.
The photographs, Figs. 105 to 107, need no description, and are
self-explanatory to a large extent.
The type of instrument used, and the accessories, are described in
detail elsewhere, as they are the standard practice adopted with all
Airostyle plants.
The writer also had the privilege of inspecting another interesting
Airostyle plant, installed at Messrs. G. Cabdy and Sons, Birmingham,
where 7 or 8 operators are employed upon high-class celluloid enamel
finishes upon buttons, medallions, cameos, electrical fittings,
and last, but not least, numerous parts for munition work, such as
cartridge clips for 18 or 24-pounders, etc.
The small articles are laid on a grid measuring about 11 inches by
9 inches, and while holding the grid the operator sprays over the
whole of the article on the grid, and in the case of rounded faces of
buttons, sprays these obliquely from all sides in turn, as well as over
the tops of the buttons.
It may be mentioned that the greater part of the spraying paints and
enamels are supplied by Messrs. Thornley & Knight, Ltd., of Birmingham.
THE BIRMINGHAM SMALL ARMS CO.
The cycle department of this well-known firm deals with an enormous,
amount of parts, and a new paint spraying department on an extensive
scale is in course of construction at Redditch, and the method in use
at the Birmingham works will be to a great extent followed. In both
cases the "Midland" sprayer is used under a pressure of from 30 to 50
lbs.
The method is very thorough, and although comparitively expensive
is well calculated to produce a finish which is (a) capable of
withstanding hard wear and possible knocks and (b) absolutely
rust-proof. The finish is elastic and very durable. It is produced by
the following method. The steel or iron parts are first thoroughly
washed in pure American turpentine in order to remove every trace of
grease and dirt. In passing, it may be said that a suitable white
spirit would probably answer as well and would effect a considerable
saving, although it is possible that the pure turpentine leaves a
certain residue behind it which is of advantage in forming a key to the
subsequent coats. The parts are then stoved, when a coat of pure Baltic
linseed oil is applied by means of brushes, and they are again stoved
at 250° F. Then a coat of black japan, known in the works as "rubber
solution," is sprayed on, and a third stoving is given in this case at
280° F. This is followed by two coats of khaki-coloured enamel sprayed
on, which dries with a semi-gloss finish. The parts are stoved between
each coat and after the final coat, so that they receive five stovings
altogether.
[Illustration: Fig. 101.--COMPRESSOR, ETC., FOR AIROSTYLE PLANT FOR 16
OPERATORS.]
[Illustration: Fig. 102.--AIROSTYLE PLANT INSTALLED FOR GAS FIRE AND
RADIATOR WORK FOR MESSRS. THE DAVIS GAS STOVE CO., LTD.]
The ovens are of special construction and are described in detail
elsewhere. The japans employed are supplied by Messrs. Arthur Holden
and Co., Ltd., of Birmingham.
Samples of the work thus finished were submitted to the author, who
carefully tested them. He found that the finish was all that could
be desired. A piece of plate metal, for instance, was bent double
without the finish being affected, thus showing very clearly the great
elasticity of the coating--a most important and necessary quality in a
finish for this class of work.
MESSRS. FLETCHER, RUSSELL & CO., LTD.
This well-known firm use spraying at their Warrington Works on an
extensive scale. All parts of gas cookers, gas stoves, and ranges large
and small, are sprayed by different sizes of the Airostyle sprayer.
Stoving takes place in most cases, and the work of spraying effects a
great saving, one man being able to do the work of at least three under
the old brush system.
Some very beautiful effects are obtained in stoves intended for use
in drawing, dining and reception rooms, by spraying various coloured
semi-transparent lacquers over silver-bright iron or steel. Rich reds,
browns, greens and blues in various shades are produced, and the bright
surface beneath the lacquer gives a very pleasing and artistic effect.
Stoving produces the necessary hardness of the lacquer, which may be
regarded as being very durable.
SPECIAL MACHINES.
The Berkel and Parnall's Slicing Machine Co., Ltd., whose extensive
works are at 6, Bow Common Lane, London, E., have had a plant for
paint spraying in use for the last four years, and find it to be quite
successful and a great saving of time over the old method of applying
the paint by means of brushes, in addition to a superior finish being
obtained. The sprayer in this case is the "Invincible," and the paint
is sprayed on under pressure varying according to the nature of the
work. The iron parts which go to make up the slicing machine are first
primed and stoved and any imperfections stopped in the usual manner.
They are then painted by means of compressed air and again stoved,
after which they receive a further coat, which is also stoved. Various
ornamentation in gold is then put on, mostly by the transfer process,
although certain parts require lining by hand. The final coat of
varnish is given by means of brushes, it being found that this is
the most economical way for this particular class of work. In this
particular it will be observed that the method differs from that used
in many other works where all the operations are done by spraying,
including a final coat of varnish. The colour used for the paint is a
bright red. There are two spraying cabinets with the usual exhaust, and
turn-tables are employed for turning the parts round to receive the
coat of paint. It may surprise some readers to learn the very large
extent to which these slicing machines are used throughout the world
for various purposes.
GITTINGS, HILLS AND BOOTHBY, LIMITED.
The plant for spraying in use in these works is principally intended
for experimental purposes in connection with the preparation of
paints, varnishes and lacquers of various descriptions which the firm
manufacture. An up-to-date type of pistol is used, with a pressure
not exceeding 30 lbs. to the inch. The work is done in a small closet
with glass sides open at one side, and a small turn-table is employed
upon which to place the article that is being sprayed. Some admirable
results are obtained with the aid of gold lacquers. It is found that
in certain varnishes the application of heat is an advantage, but as
a rule the spraying is done cold. Among the articles which have been
painted are motor cars and various smaller appliances.
THE KINGSBURY MANUFACTURING CO., LTD.
A typical plant for finishing picture frames, furniture, fancy
articles such as wood, cane and other ornamental baskets, is that of
the Kingsbury Manufacturing Co., Ltd., 1, Markfield Rd., Broad Lane,
Tottenham, N. This firm are the inventors of what is known as the
"Inolite" system of gilding, which is described as an ideal process.
Certainly the work produced is as near perfection as one would desire,
the gilding being excellent in appearance, while it is guaranteed for
five years to be free from discoloration or tarnishing. The process
consists in applying by means of spraying, first, a coat of special
enamel, which when dry is rubbed down with a solvent applied by a
pad. Upon this is sprayed a coat of gold paint, and a final coat of
colourless celluloid varnish is given which protects the gold from
tarnishing. The process adopted is described in greater detail under
the head of "Picture Frame Finishing" in this book.
[Illustration: Fig. 103.--VIEW FROM ONE END OF MESSRS. LUCAS, LTD.,
AIROSTYLE PLANTS, SHOWING FAN AND COMPRESSOR DRIVES.]
The coloured celluloid enamels which are applied to fancy baskets,
etc., have a very attractive metallic appearance, which is far superior
to the ordinary crude bronzy effect. Another speciality of the firm is
the finish of frames in special black, which gives a perfectly smooth
finish which might be called "egg-shell gloss." It is quite artistic in
appearance, eminently suitable for the particular purpose, and gives a
durable frame at a comparatively small cost.
The firm estimate the saving of time by using the spraying as compared
with that of employing a brush is as 5 is to 1. They point out that
a little extra material is required, but this is not begrudged as it
possesses advantages in an increased durability of the protective
coating.
THE GAS LIGHT AND COKE CO.
Several of the works of this company, which deal with gas meters,
are fitted with paint spraying installations. The branch at Laburnum
Street, Kingsland Road, in charge of Mr. W. F. Fagan, may be taken as
a type. Two Aerographs and three Airostyles are in use. The old meters
that come to the works are examined, and if the paint is in fairly good
condition the surface is rubbed down with pumice stone and water, but
if it is much decayed the meters are placed in a hot bath containing a
solution of lime and caustic soda, and allowed to remain in it a short
time, when the paint becomes so soft as to be easily removable. The
surface of new tinplate is cleaned down with spirit, when it is quite
ready to receive the coat of paint. At these works many different makes
of meters come in to be dealt with, hence various masks are necessary
to protect those parts which it is not desired to spray. The pressure
used here is rather more than usual, being 40 lbs. to the sq. inch. The
time taken to paint a meter is very small, as can be understood when
it is said that two men working on five-light meters can turn out 30
an hour. Before the spraying apparatus was put in, about a year ago, a
man could paint with a brush about three meters in an hour, so that,
with the present system, there is an immense saving. It is calculated
that the whole of the original outlay of putting in the plant will be
returned at the end of about a year.
The masks or shields having been placed in position, a cap is placed
over each union and the paint is sprayed on. The meters are turned out
at the rate of 900 to 1,500 a week of 48 hours. The spraying apparatus
is provided with the usual exhaust consisting of two 9-inch holes
to each cabinet, with grating over. About 10 per cent, more paint is
allowed than that used when it is applied by hand, but the greater part
of this goes on the surface, and the coat of paint as a protector is
distinctly improved. The exhaust is carried up to the roof, but the
actual loss of paint is very small.
Fig. 108 shows a general view, and a large central draught steel
plate fan is employed to exhaust the hoods, and to drive this and the
compressor a gas engine is employed. The compressor is of the type
illustrated in Fig. 71, page 115, and can just be discerned behind the
gas engine.
Fig. 109 shows a gas meter in position, with the necessary masks fixed,
and Fig. 110 shows the operator about to spray-paint same. This plant
has been in daily operation for more than two years.
THE GAS METER CO., LIMITED.
The installation of a spraying plant at the works of this firm, which
are at 238, Kingsland Road, have been in operation for rather less than
a year, but has proved quite satisfactory. Various types of gas meters
are sprayed with one coat of Torbay paint, which is an iron oxide paint
of high quality, and the one coat possesses amply sufficient quality
to give a good covering. Prior to painting the surface of the tinned
plate which is used for gas meters, it is cleaned down with a piece of
waste dipped in spirit. Masks are used to fit over name plates, etc.,
and the spraying is done in the usual cabinet, with an exhaust. A three
or four-light meter takes about two minutes to do, and the larger
sizes, of course, longer in proportion. All sizes up to and including
500-light meters are sprayed, but those larger, up to 1,000 lights,
are a little too big to handle. The greater part of the meters are
done in deep red oxide iron colour, but three other colours are used
in addition, as may be required. The meter to be sprayed is placed on
a turn-table which bears on a sharp steel point and has on its upper
portion spikes or ridges, to hold the meter in position. The Aerograph
spray is employed in this case.
[Illustration: Fig. 104.--GENERAL VIEW OF AIROSTYLE PLANTS AT MESSRS.
LUCAS' LTD.]
[Illustration: Fig. 105.--J. LUCAS, LTD., AIROSTYLE PLANTS, SHOWING THE
AMPLE SPACE BETWEEN HOODS.]
[Illustration: Fig. 106.--J. LUCAS, LTD., AIROSTYLE PLANTS, SHOWING
THE METHOD OF EMPLOYING RACKS TO GREATER ADVANTAGE, AND ALSO GIVING A
CLEARER IDEA OF THE LARGE FAN EMPLOYED.]