BS-7079-D1-1993 ISO-8504-1-1992.pdf

BRITISH STANDARD BS 7079-D1: 1993 ISO 8504-1: 1992 Preparation of steel substrates before application of paints and related products Group D: Methods for surface preparation Part D1: General principles UDC 667.648.1:669.14:621.7.02 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7079-D1:1993 This British Standard, having been prepared under the direction of the Pigments, Paints and Varnishes Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 April 1993 © BSI 02-1999 The following BSI references relate to the work on this standard: Committee reference PVC/21 Draft for comment 88/50739 DC ISBN 0 580 21689 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Pigments, Paints and Varnishes Standards Policy Committee (PVC/-) to Technical Committee PVC/21, upon which the following bodies were represented: Association of Consulting Engineers British Chemical Engineering Contractors Association British Constructional Steelwork Association Ltd. British Gas plc British Grit Association British Railways Board British Steel Industry Department of Transport Electricity Association Institute of Corrosion National Federation of Painting and Decorating Contractors Oil and Colour Chemists Association Paint Research Association Paintmakers Association of Great Britain Ltd. Royal Society of Chemistry Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7079-D1:1993 © BSI 02-1999i Contents Page Committees responsible Inside front cover National foreword ii Introduction1 1Scope 1 2Normative references 1 3General 2 4Condition of the surface to be prepared 3 5Selection of the surface preparation method 3 6Selection of the preparation grade 4 7Assessment of the prepared surface4 List of references Inside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7079-D1:1993 ii © BSI 02-1999 National foreword This Part of BS 7079 has been prepared under the direction of the Pigments, Paints and Varnishes Standards Policy Committee. It is identical with ISO 8504-1:1992 Preparation of steel substrates before application of paints and related products Surface preparation methods Part 1: General principles, published by the International Organization for Standardization (ISO). This standard makes an informative reference to ISO 8502-4 which is in preparation. It is evisaged that when ISO 8502-4 is published it will be implemented, dual-numbered, as BS 7079-B4. Cross-references International standardCorresponding British Standard BS 3900 Methods of test for paints ISO 4628-2:1982Part H2:1983 Designation of degree of blistering (Identical) ISO 4628-3:1982Part H3:1983 Designation of degree of rusting (Identical) ISO 4628-4:1982Part H4:1983 Designation of degree of cracking (Identical) ISO 4628-5:1982Part H5:1983 Designation of degree of flaking (Identical) BS 7079: Preparation of steel substrates before application of paints and related products ISO 8501-1:1988Part A1:1989 Specification for rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings (Identical) ISO 8502-2:1992Part B2:1992 Method for determination of chlorides on cleaned surfaces (Identical) ISO 8503-1:1988Part C1:1989 Specification for surface profile comparators for the assessment of abrasive blast-cleaned surfaces (Identical) ISO 8503-2:1988Part C2:1989 Method for the grading of surface profile of abrasively blast-cleaned steel using a comparator (Identical) ISO 8503-3:1988Part C3:1989 Method for the calibration of surface profile comparators and for the determination of surface profile using a focusing microscope (Identical) ISO 8503-4:1988Part C4:1989 Method for the calibation of surface profile comparators and for the determination of surface profile using a stylus instrument (Identical) ISO 8504-2:1992Part D2:1993 Abrasive blast-cleaning (Identical) ISO/TR 8502-1:1991DD 207:1992 Method of test for soluble iron corrosion products to assess surface cleanliness of steel substrates before application of paints and related products (Identical) Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7079-D1:1993 © BSI 02-1999iii The Technical Committee has reviewed the provisions of ISO 8501-2 and ISO 8502-3:1992, to which normative reference is made in the text and has decided that they are acceptable for use in conjunction with this standard. It is intended that, when ISO 8501-2, currently in preparation, is published it will be implemented, dual-numbered, as BS 7079-A2 and that ISO 8502-3 will be implemented, dual-numbered, as BS 7079-B3 after the correction of a technical error. Further information on the ISO 8501, ISO 8502, ISO 8503 and ISO 8504 series of standards is given in BS 7079 Preparation of steel substrates before application of paints and related products Part 0: Introduction. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 8504-1:1992(E) © BSI 02-19991 Introduction The performance of protective coatings of paint and related products applied to steel is significantly affected by the state of the steel surface immediately prior to painting. The principal factors that are known to influence this performance are a) the presence of rust and mill scale; b) the presence of surface contaminants, including salts, dust, oils and greases; c) the surface profile. International Standards ISO 8501, ISO 8502 and ISO 8503 have been prepared to provide methods of assessing these factors, while ISO 8504 provides guidance on the preparation methods that are available for cleaning steel substrates, indicating the capabilities of each in attaining specified levels of cleanliness. These International Standards do not contain recommendations for the protective coating systems to be applied to the steel surface. Neither do they contain recommendations for the surface quality requirements for specific situations even though surface quality can have a direct influence on the choice of protective coating to be applied and on its performance. Such recommendations are found in other documents such as national standards and codes of practice. It will be necessary for the users of these International Standards to ensure that the qualities specified are compatible and appropriate both for the environmental conditions to which the steel will be exposed and for the protective coating system to be used; within the capability of the cleaning procedure specified. The four International Standards referred to above deal with the following aspects of preparation of steel substrates: ISO 8501 Visual assessment of surface cleanliness; ISO 8502 Tests for the assessment of surface cleanliness; ISO 8503 Surface roughness characteristics of blast-cleaned steel substrates; ISO 8504 Surface preparation methods. Each of these International Standards is in turn divided into separate parts. The primary objective of surface preparation is to ensure the removal of deleterious matter and to obtain a surface that permits satisfactory adhesion of the priming paint to the steel. It should also assist in reducing the amounts of contaminants that initiate corrosion. This part of ISO 8504 describes the general principles for the selection of surface preparation methods. It should be read in conjunction with ISO 8504-2 and subsequent parts of ISO 8504 that describe particular surface preparation methods. It is stressed that there is a very wide variation in the condition of steel surfaces requiring cleaning prior to painting. This particularly applies to maintenance of an already coated structure. The age of the structure and its location, the quality of the previous surface, the performance of the existing coating system and the extent of breakdown, the type and intensity of previous and future corrosion environments, and the intended new coating system all influence the amount of treatment required. 1 Scope This part of ISO 8504 describes the general principles for the selection of methods for the preparation of steel surfaces before coating with paints and related products. It also contains information on features that must be taken into account before certain surface preparation methods and preparation grades are selected and specified. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 8504. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 8504 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 4628-2:1982, Paints and varnishes Evaluation of degradation of paint coatings Designation of intensity, quantity and size of common types of defect Part 2: Designation of degree of blistering. ISO 4628-3:1982, Paints and varnishes Evaluation of degradation of paint coatings Designation of intensity, quantity and size of common types of defect Part 3: Designation of degree of rusting. ISO 4628-4:1982, Paints and varnishes Evaluation of degradation of paint coatings Designation of intensity, quantity and size of common types of defect Part 4: Designation of degree of cracking. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 11:42:45 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 8504-1:1992(E) 2 © BSI 02-1999 ISO 4628-5:1982, Paints and varnishes Evaluation of degradation of paint coatings Designation of intensity, quantity and size of common types of defect Part 5: Designation of degree of flaking. ISO 8501-1:1988, Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings. ISO 8501-2:1), Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness Part 2: Preparation grades of previously coated steel substrates after localized removal of previous coatings. ISO/TR 8502-1:1991, Preparation of steel substrates before application of paints and related products Tests for the assessment of surface cleanliness Part 1: Field test for soluble iron corrosion products. ISO 8502-2:1992, Preparation of steel substrates before application of paints and related products Tests for the assessment of surface cleanliness Part 2: Laboratory determination of chloride on cleaned surfaces. ISO 8502-3:1992, Preparation of steel substrates before application of paints and related products Tests for the assessment of surface cleanliness Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method). ISO 8502-4:1), Preparation of steel substrates before application of paint and related products Tests for the assessment of surface cleanliness Part 4: Guidance on the estimation of the probability of condensation prior to paint application. ISO 8503-1:1988, Preparation of steel substrates before application of paints and related products Surface roughness characteristics of blast-cleaned steel substrates Part 1: Specifications and definitions for ISO surface profile comparators for the assessment of abrasive blast-cleaned surfaces. ISO 8503-2:1988, Preparation of steel substrates before application of paints and related products Surface roughness characteristics of blast-cleaned steel substrates Part 2: Method for the grading of surface profile of abrasive blast-cleaned steel Comparator procedure. ISO 8503-3:1988, Preparation of steel substrates before application of paints and related products Surface roughness characteristics of blast-cleaned steel substrates Part 3: Method for the calibration of ISO surface profile comparators and for the determination of surface profile Focusing microscope procedure. ISO 8503-4:1988, Preparation of steel substrates before application of paints and related products Surface roughness characteristics of blast-cleaned steel substrates Part 4: Method for the calibration of ISO surface profile comparators and for the determination of surface profile Stylus instrument procedure. ISO 8504-2:1992, Preparation of steel substrates before application of paints and related products Surface preparation methods Part 2: Abrasive blast-cleaning. 3 General When selecting a surface preparation method, it is necessary to consider the preparation grade required to give a level of surface cleanliness and, if required, a surface profile (roughness), such as coarse, medium or fine (see ISO 8503-1 and ISO 8503-2), appropriate to the coating system to be applied to the steel surface. Since the cost of surface preparation is usually in proportion to the level of cleanliness, a preparation grade appropriate to the purpose and type of coating system or a coating system appropriate to the preparation grade which can be achieved should be chosen. Firms carrying out surface preparation work should have the personnel and technical knowledge of the processes involved to enable them to carry out the work adequately. All relevant health and safety regulations shall be observed. The surfaces to be treated should preferably be readily accessible and sufficiently illuminated. All surface preparation work should be properly supervised and inspected. Details regarding the preliminary treatment of welds, the removal of weld spatter and removal of burrs and other sharp edges should