Chapter I: Preface

In many industries the application of paint for preservative or ornamental purposes is imperative and the item of expenditure is an important one.

There is abundant evidence to prove that the application of paint, either by means of dipping, spraying or other mechanical means, effects an enormous saving of time over the old method of using brushes, while the coats of paint are more durable and thorough.

This saving of time not only lowers the cost of production to a very considerable extent, but it permits of a large increase in the output.

The process of "flowing-on" enamels and varnishes described in the following pages effects an even greater saving of time in those cases where it is applicable. The extent of this saving can be judged by the fact that a complete coat of enamel can be given to the body of a four-seated touring car in the almost incredibly short time of two minutes!

These processes are used to a very large extent in many industries, particularly those connected with metal work and engineering. In the United States of America and in many parts of the Continent they have reached a high degree of perfection. In Great Britain the adoption of the methods is rapidly increasing.

It is hoped that this book will be found of service to manufacturers who desire to ascertain whether the processes can be economically employed in their particular industry or to those who contemplate putting in a plant for the purpose.

It should also be helpful to those who have not been very successful with a trial plant or who desire to bring an existing plant fully up-to-date in its equipment. And it should be said at once that the few cases of failure which have come to the notice of the author have been found on investigation to be due either to the use of paint unsuitable for the purpose or the adoption of a plant which is unfitted for the object aimed at. Three examples may be given. In one small castings were dipped in black paint, but it was found that "tears," or runs of paint which did not dry properly, often occurred. Here, clearly, the paint was at fault. It was too thick for the purpose and did not dry hard quickly enough. The remedy was obvious.

In another case iron casements were dipped horizontally in a shallow paint tank and the time involved in lowering them to obtain a complete immersion was considerable. In this case the shape and size of the tank were not suitable. It should have been deep and narrow, so that the casements could be dipped vertically. The idea that the paint would "settle out" if a deep tank were used was shown to be erroneous.

In a third case spraying had been tried for coating metal casements, when it was found that the saving effected in time was more than counter-balanced by the waste of paint. Of course, spraying was not suitable for a job of this kind, the surface to be covered being so very narrow. Such work is done most successfully by dipping.

The degree of perfection to which the process of dipping has been carried in America is indicated by the fact that it is largely employed for piano cases and many other articles requiring a perfect varnish finish. This process is fully described in these pages and has been successfully carried on for some years. This fact demonstrates very clearly the possibilities of painting and varnishing by immersion.

All the principal appliances used for spraying paint, lacquer, enamel, varnish and similar liquids have been described at length, but no attempt has been made to prove that any one appliance is superior to another. The details of each apparatus are given, and for the convenience of the reader, the manufacturer's name and address. It is suggested that those who contemplate the adoption of paint dipping, or spraying, should get into touch with all these firms, and carefully investigate their respective merits before coming to a decision.

The services of an expert will usually be found desirable, for, although in engineering works much of the necessary apparatus and accessories may be made on the premises, the exact details, such as the kind of paint and the exact design suitable for the particular purpose, are largely matters to be decided upon in the light of experience.

ARTHUR S. JENNINGS.

365, Birkbeck Bank Chambers,
High Holborn, W.C.

August, 1915.

CONTENTS.

CHAPTER I. PAGE

INTRODUCTION.

Increase in the Use of Painting by Dipping and Spraying--The
Remarkable Saving of Time Effected--The Durability Equal
to Brush Painting--Scope of the Subject--Whitewashing
Machines--Cost of Spraying Plant--Dipping Plant may be
very Simple--List of the Principal Products to which Paint
Spraying is Applied 1

CHAPTER II.

PAINTING BY IMMERSION.

An old Idea largely Developed in Recent Years--Simple Forms of
Paint Dipping--Painting Varnish Cans--Larger Plants--The
Tank--The Agitators--McLennan Patent--Paint Proof
Gear Box--Three Tank Plant for Different Colours--The
Rails and Hanging Apparatus--Hanging Articles after they
are Painted--Hoists--Simple Crabs and Lifting Gear--Pneumatic
Hoist--Electrical Hoist--Trolley Hoist--The
Number of Coats of Paint--Advantages of the Dipping
Process--Protecting Parts not to be Painted--Preparing
Woodwork before Painting--Filler for Iron--Stopping Holes in
Woodwork--Rubbing Down 7

CHAPTER III.

REQUIREMENTS OF DIFFERENT TRADES.

Bedsteads--Collapsible Gates--Dipping Sewing Machine Parts--Iron
Rods--Iron Window Frames or Casements--Metal
Furniture--Motor Parts (Metal)--Automatic Finishing of
Pianos--The Standard Hydraulic Immersion System--Wheels--Some
Typical Plants--Carriage Department, Woolwich
Arsenal--James Gibbons--Harrison, McGregor & Co.--Phillips
& Son--The Ford Motor Company--Marshall, Sons &
Co., Ltd.--Hayward Bros. & Eckstein, Ltd.--The Crittall
Manufacturing Co.--Excluding Dust--Heating and Ventilation
of Drying Room--A Model Drying Room 33

CHAPTER IV.

PAINT FOR DIPPING.

The Requirements of a Good Dipping Paint--Specific Gravity of
Pigments--White Dipping Paint--Gloss Paint--W. G. Scott
on Dipping Paints--Proportion of Paste and Thinners--Asbestine
--China Clay--Whiting--Zinc Oxide--Inert
Materials--Primers for Metal--Primers for Hard and Soft
Woods--Second Coat Dipping Paints--White Paste Primer--White
Dip for Metals--White Dip for Hard Wood--White
Dip for Soft Wood--White Spirit--Quantity of Paint
Required for Dipping and Spraying--Spreading Capacity
of Paints 70

CHAPTER V.

PAINTING BY COMPRESSED AIR.

The Evolution of the Apparatus Employed--Early Attempts--The
Concentric Form of Spray--Its Advantages--The Flow of
Paint--Practice Necessary--Cost of Plant--Pressure and
Volume of Air Required 78

CHAPTER VI.

TYPES OF SPRAYING APPARATUS.

The Aerograph--Electric Motor Outfit--Painting a Gasometer--Small
Aerograph--The Aeron--Uniformity of Coats--Cup
Aeron--Air Transformer--The Airostyle--Construction--"Ultra"
type--Pistol "M"--The Eureka Spraying Machine--The
Crane Eureka--The Crane "Record"--The "Invincible"--Type
"E"--Artists' Type--The Midland
Sprayer--The "Paasche" Sprayer--Larger Size--Oil and
Water Separator--Automatic Electric Controller 81

CHAPTER VII.

SUPPLY OF COMPRESSED AIR--PAINT SUPPLY--EXHAUST.

Type of Compressor--Air Main--Air Valves--Purifying Air--Small
Compressors--Water Cooling--Air Pump and Tank
Combined--General Arrangement of Accessories--The Supply
of Paint--The Exhaust Installation--Central Draught Fan--Location
of Work Cabinets--The Fumexer Spraying Cabinet--Accessories
--Turn-tables, Auto--Electric Air Heater 113

CHAPTER VIII.

STENCILS AND MASKS--THE REQUIREMENTS OF DIFFERENT
TRADES IN SPRAYING.

Protecting parts not to be Sprayed--Masks for Gas Meters--The
Hart Patent Mask--Making Stencils--Stencil Paper--Four-ounce
Stencil Metal--Zinc Stencils--Requirements of Special
Trades--Piece Work--Bookbinding--Carriages--Cycle Parts--Electrical
Work--Fancy Baskets--Gas Meters--Gas Stoves
and Ranges--Picture Frames, Picture Mouldings, etc.--Celluloid
Varnish--Spraying Ships' Hulls--Slate Enamelling--Spraying
Colour Specimens--Tramcars 141

CHAPTER IX.

SOME TYPICAL PLANTS.

Plant for Twelve Operators--The Birmingham Small Arms Co.--Airostyle
Plant for Sixteen Operators--The Davis Gas Stove
Co., Ltd.--Fletcher, Russell & Co., Ltd.--Special Machines
--Gittings, Hills and Boothby, Ltd.--The Kingsbury Manufacturing
Co., Ltd.--J. Lucas, Ltd.--The Gas Light and Coke
Co., Ltd.--The Gas Meter Co., Ltd 158

CHAPTER X.

PAINTS, LACQUERS, VARNISHES, ETC., USED IN SPRAYING.

Temperature of Spraying Room--Fine Paint must be used--Firms
who Specialize on Dipping and Spraying Paints, etc.--Stoving
Enamels--Enamels--Hints on Stoving or Baking--Black
Japan Finishes--Steel Furniture Enamels--Imitation Wood
Effects--White Work--Bedsteads, etc.--Transparent Colour
Varnishes--Safe Baking Heats of Pigment Colours--Dipping
and Spraying Compared 177

CHAPTER XI.

SPRAYING VERSUS BRUSHING.

Comparison with Brush Painting--Bronzing with Celluloid
Medium--Objections Sometimes Urged Against Spraying---Mottled
Appearance of Paint and how Avoided--Spraying
Fillers and Primers--Spraying and Dipping Compared--The
Great Saving Effected 193

CHAPTER XII.

THE ARTISTIC APPLICATION OF PAINT SPRAYING.

Artistic Work--Lining on Motors and Carriages--Relief Work
--Scumbling and Colour Glazing--Glazing--Designs for Lamp
Shades--Reds--Blues--Yellows--Greens--Browns--Greys--Scumbling
and Graining--Brush Graining--Marble Grounds--Graining
Grounds 201

CHAPTER XIII.

THE "FLOWING-ON" SYSTEM.

The Latest Method of Finishing Automobiles--Remarkable Speed
of the Method--The Apparatus--Trough Tank used in the
Process--The Kind of Paint or Japan Used--The Floco Process
--Painting Motor Bodies--Description of Modern Enamelling
Ovens for Motor Bodies--Notes on the Construction of Stoves--The
Perkins' Stove--Typical Goodyear Stove--Dipping
Trough 216

CHAPTER XIV.

LIME AND WHITEWASH SPRAYERS.

Periodical Whitewashing in Workshops Compulsory--The Wells
Sprayer--Limewhiting by Machine with 8-foot Bamboo Pole--The
Brown Sprayer--The Merryweather Sprayer--The
Tumbling Barrel Process 243

CHAPTER XV.

A PORTABLE PAINT SPRAYER FOR RAILWAY AND OTHER WORK.

The Pennsylvania Railroad System--fainting Freight Cars--Description
of Apparatus--Plan and Elevation--Detail
Drawings 250