Organic Coatings : Properties, Selection, And
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DATE DUE OCT 2 9 1974 1 i ! 30 501 JOSTEN-S are used for Organic coatings in the form of paints, varnishes, lacquers, and related products from chil- protective, decorative, and functional purposes on a wide variety of man's products— identification, environ- dren's toys to guided missiles. On rockets and spacecraft, paints provide mental protection, and temperature control. UNITED STATES DEPARTMENT OF COMMERCE"'"' Alexander B. Trowbridge, Secretary '~~T A NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director A/7 Organic Coatings Properties, Selection, and Use Aaron Gene jRobeils Building Research Division Institute for Applied Technology National Bureau of Standards Washington, D.C. 20234 Building Science Series 7 Issued February 1968 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $2.50 Abstract This publication was prepared to fill the need for a comprehensive, unifying treatise in the field of organic coatings. Besides presenting practical information on the properties, selection, and use of organic coatings (and certain inorganic coatings), it provides basic principles in a number of important areas such as polymer structure, coatings formulation, pigment function, use of thinners, coating system compatibility, and theory of corrosion. Each chapter deals with a major area of the coatings field, including types of coatings, properties of synthetic resins, selection of coating systems, storage and safety, application methods, and surface preparation and pretreatment. There is also a consolidating chapter with illustrative examples of solutions to typical coatings problems. Interrelationships among the various areas of information are indicated through appropriate cross-referencing in the text. Specific references to Federal, Military, and other specifications are given where pertinent, and an entire chapter is devoted to a quick guide and summary of Federal specifications for organic coating materials. Finally, a selected bibliography and a comprehensive index are provided. While written primarily to meet the informational needs of the engineer, architect, maintenance superintendent, and responsible coatings procurement officer, the treatise is sufficiently broad in scope to serve as a general manual, a concise text, or a convenient reference source in the field of organic coatings. Key words: application, coatings, coating systems, corrosion-inhibiting. Federal specifications, fire-retardant, lacquer, latex, multicolor, organic coatings, paint, pigments, polymers, properties, resins, selection, substrates, surface preparation, varnish, water-thinned. Library of Congress Catalog Card No. 66-61927 II Foreword Since publication in 1945 of the Paint Manual issued as National Bureau of Standards Building Materials and Structures Report 105, there have been many significant techno- logical advances in the field of organic coatings. Materials and techniques that were nonexistent or only dimly foreseen twenty years ago are now in daily use. Coatings with new and improved properties emerge continually from research laboratories and production lines. The task of choosing wisely from this huge array of materials is a complex and difficult one that requires both a knowledge of what is available and an understanding of where and how these materials and techniques can best be utilized. The present publication was written to fill this need. Through careful selection and orderly presentation of information, it has been possible to include a broad range of subject matter not previously available within a single volume. Practical information is given on the properties, selection, and application of organic coatings, including methods of adequate surface preparation. Basic principles also are discussed. Thus, a description is given of the polymeric nature of the synthetic resins that are the basis for most of our modern coating systems, and relationships between polymer structure and properties are indicated. A unique feature which should prove useful to those concerned with the procurement or supply of organic coatings for the Government is a quick guide to Federal specifications for these materials in the form of a classified table and a series of summarizing charts. Names and descriptions of some specific proprietary products are included for the convenience of the user. The omission of any particular product does not imply that it is considered unsuitable or unsatisfactory. Conversely, inclusion of a particular proprie- tary product does not constitute endorsement. Photographs of proprietary instrumenta- tion and apparatus are included for illustrative and educational purposes and do not constitute approval or endorsement of the particular product. Use of the information given herein for advertising or publicity purposes is not authorized. For the architect, engineer, maintenance superintendent, procurement officer, and others responsible for the proper selection and application of organic coating systems, this volume should be useful as a general manual, a unifying text, or a convenient source of authoritative information. A. V. AsTiN, Director. m — Preface Paints of the pigment-in-oil type have long provided man with durable protective and decorative coatings for his houses and other structures. Such paints, improved and embellished with new pigments in a wide variety of colors, are useful even today. In recent years, however, paralleling the tremendous growth of the plastics industry, conventional paints have given way more and more to new and often superior coatings based on the new synthetic resins and the new formulating techniques that have been developed. The list of available and useful film-forming materials is almost as long as the roster of different plastics, resins, and cellulose derivatives. These materials, singly or in physical admixture or chemical combination, have been modified with a wide variety of pigments, plasticizers, extenders, activators, stabilizers, solvents, and diluents to produce an almost endless proliferation of coating materials, each with its own set of useful properties. The information problem confronting those who must choose wisely from this bewildering array is indeed a formidable one. It is a basic purpose of this publication to familiarize responsible personnel in the Federal establishment and elsewhere with the types of coating materials that are available, and to organize the essential information concerning such materials in a manner that will permit the selection and application of an adequate coating system for a particular job without requiring that the individuals responsible be or become expert coatings technologists. The sheer magnitude of the problem precludes a discussion or even merely a listing of every material; nor would such an approach be desirable in anything but an encyclo- pedic treatment of the subject. Instead, the guiding philosophy throughout the prepara- tion of this volume has been to anticipate and to meet the practical informational needs of the engineer, architect, maintenance superintendent, and coatings procurement officer while keeping in mind the need for conciseness and clarity. This volume is not intended to take the place of the many excellent manuals tailored in detail to the specific needs of a specialized Government agency or activity. Rather, it offers a broad survey of the field of organic coatings that will serve to orient the reader and may be useful in indicating areas in which available manuals might advantageously be modified to utilize the newer materials and techniques. The information has been selected and presented in a manner that will provide maximum usefulness when the monograph is used as an ajunct to the handbooks and manuals of particular agencies to provide basic information and practical working details not usually found in the more specialized manuals. The author wishes to express his deep appreciation to Paul T. Howard, Head, Organic Coatings Group, National Bureau of Standards, for his encouragement, critical review, and many constructive suggestions throughout the preparation of this work. Grateful acknowledgment is made to Dr. S. G. Weissberg of this Bureau for his scholarly review of the completed manuscript. Other NBS colleagues to whom the author is indebted are Dr. A, F. Robertson, for his review of the information on fire-retardant coatings; Dr. R. Florin, for reviewing the section on effects of high energy radiation; W. C. Cullen, for his review of the section on bituminous coatings; and Dr. W. W. Walton, for his overall review of the manuscript. The author wishes to thank J. H. Geyer of Amchem Products, Inc., G. R. Hoover of Armco Steel Corporation, and M. B. Roosa of Parker Rust Proof Division, Hooker Chemical Corporation, for their valued review of the material on pretreatment of steel, aluminum, and galvanized surfaces. Appreciation is expressed also to Anthony Gallaccio, Frankford Arsenal, for his constructive review of the section on surface preparation and pretreatment of magnesium and its alloys. Finally, the author's great debt to the literature on organic coatings is humbly acknowledged. It is hoped that this volume will contribute tangibly to the knowledge and perspective so essential for the wise choice and proper application of modern coating systems. A. G. Roberts. Washington, D.C. Contents Page Abstract ii Foreword III Preface v 1. Introduction 1 1.1. Scope 1 1.2. Basic objectives and arrangement of information 1 1.3. Structure and use of the index 2 1.4. Historical background ^ 3 1.4.1. Early history of varnish and paint 3 1.4.2. Twentieth-century developments 3 2. Types of coatings 5 2.1. General description and basis for classification 5 2.2. Clear coatings 5 2.2.1. Drying oils 5 2.2.1.1. Linseed 6 2.2.1.2. Tung 6 2.2.1.3. Dehydrated castor 6 2.2.1.4. Perilla, oiticica 6 2.2.1.5. Refined fish oils 6 2.2.1.6. Semi-drying oils 6 2.2.1.7. Non-drying oils 6 2.2.1.8. Tall oil 6 2.2.2. Varnish 6 2.2.3. Spirit varnish 7 2.2.4. Lacquer , 7 2.2.5. Sealer 7 2.2.6. Wax polishes 8 2.2.7. Strippable coatings 8 2.2.8. Synthetic resin coatings 9 2.3.