BS EN ISO 8502-9-2001

BRITISH STANDARD BS EN ISO 8502-9:2001 BS 7079-B9:1998 Incorporating Amendment No. 1 Preparation of steel substrates before application of paints and related products — Group B: Methods for the assessment of surface cleanliness — Part B9: Field method for the conductometric determination of water-soluble salts ICS 17.040.20; 25.22.10; 87.020 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI BS EN ISO 8502-9:2001 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 August 1998 © BSI 06-2001 ISBN 0 580 30219 9 National foreword This British Standard is the official English language version of EN ISO 8502-9:2000, Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface of cleanliness — Part 9: Field method for the conductometric determination of water-soluble salts, including amendment A1:2000, and implements it as the UK national standard. It reproduces verbatim ISO 8502-9:1998. The original BS identifier BS 7079-B9:1998 has been retained for ease of cross-reference. The UK participation in its preparation was entrusted to Technical Committee STI/21, Surface preparation of steel, which has the responsibility to: — aid enquirers to understand the text; — present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; — monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. 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 and ii, the EN title page, the EN foreword page, the ISO title page, the ISO foreword page, pages 1 to 4, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Sidelining in this document indicates the most recent changes by amendment. Amendments issued since publication Amd. No. Date Comments 12095 June 2001 Indicated by a sideline Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com BS EN ISO 8502-9:2001 © BSI 06-2001 i Contents Page National foreword Inside front cover Introduction 1 1 Scope 1 2 Normative references 1 3 Principle 2 4 Solvent 2 5 Apparatus and materials 2 6 Procedure 2 7 Expression of results 3 8 Accuracy 5 9 Text report 5 Figure 1 — The total surface density �A of the salts as a function of the change in conductivity �� 4 Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com ii blank Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EUROPEAN STANDARD NORME EUROPÉEENNE EUROPÄISCHE NORM EN ISO 8502-9 August 2000 + A1 December 2000 ICS 87.020 Emglish version Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 9: Field method for the conductometric determination of water-soluble salts (ISO 8502-9:1998 + A1:2000) Préparation des subjectiles d’acier avant application de peintures et de produits assimilés — Essais pour apprécier la propreté d’une surface — Partie 9: Méthode in situ pour la détermination des sels solubles dans l’eau par conductimétrie (ISO 8502-9:1998 + A1:2000) This European Standard was approved by CEN on 6 August 2000. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 2000 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8502-9:2000 + A1:2000 E Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 © BSI 06-2001 Foreword The text of the International Standard from Technical Committee ISO/TC 35, Paints and varnishes, of the International Organization for Standardization (ISO), including amendment A1:2000; has been taken over as a European Standard by Technical Committee CEN/TC 139, Paints and varnishes, the Secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2001, and conflicting national standards shall be withdrawn at the latest by February 2001. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com Amendment 1 1999-12-02 Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 8502-9 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 12, Preparation of steel substrates before application of paints and related products. ISO 8502 consists of the following parts, under the general title 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 [Technical Report]; — Part 2: Laboratory determination of chloride on cleaned surfaces ; — Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method); — Part 4: Guidance on the estimation of the probability of condensation prior to paint application; — Part 5: Measurement of chloride on steel surfaces prepared for painting — Ion detection tube method; — Part 6: Extraction of soluble contaminants for analysis — The Bresle method ; — Part 7: Field method for determination of oil and grease ; — Part 8: Field method for refractometric determination of moisture ; — Part 9: Field method for the conductometric determination of water-soluble salts; — Part 10: Field method for the titrimetric determination of chloride. Descriptors: Paints, varnishes, substrates, steel products, tests, field tests, determination, surface condition, cleanliness checks, conductimetric methods. Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 © BSI 06-2001 1 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 system 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. This part of ISO 8502 describes a field method for the assessment of the total amount of water-soluble salts, the salts being regarded as forming one single contaminant. The more aggressive contaminants causing corrosion and blistering (the ionic species) can easily be dissolved off and determined rapidly by this method. Consequently, the less aggressive and not so easily dissolved minor part of contaminant will remain un-assessed. For additional information on the test method, its potential and its limitations, see BRESLE, Å., Conductometric determination of salts on steel surfaces, MP (Materials Performance), June 1995, Vol. 34, No. 6, pp. 35-37, NACE International, Houston TX, USA. Rusty steel substrates, particularly those of rust grades C or D (see ISO 8501-1), even when blast-cleaned to preparation grade Sa 3 (see ISO 8501-1 and ISO 8501-2), may still be contaminated by water-soluble salts and corrosion products. These compounds are almost colourless and are localized at the lowest point of the rust pits. If they are not removed prior to painting, chemical reactions can result in blister formation and accumulations of rust that destroy the adhesion between the substrate and the applied protective coating. 1 Scope This part of ISO 8502 describes a field method for the assessment of the total surface density of various water-soluble salts (mostly chlorides and sulfates) on steel surfaces before and/or after surface preparation. The individual surface densities of chlorides, sulfates, etc., cannot be determined by this method. This method assesses ionic contaminants only. These represent the greater part of the contamination. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 8502. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreement based on this part of ISO 8502 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. Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 2 © BSI 06-2001 ISO 3696:1987, Water for analytical laboratory use — Specification and test methods. ISO 8502-6:1995, Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 6: Extraction of soluble contaminants for analysis — The Bresle method 3 Principle The salts on the given area of the steel surface are dissolved by the Bresle method (see ISO 8502-6), using water as solvent. The conductivity of the solution thus obtained is measured. Finally, the total surface density of the salts in this area is calculated by a simple but sufficiently accurate equation. 4 Solvent Water of at least grade 3 purity in accordance with ISO 3696. NOTE Usually, distilled or de-ionized water of conductivity less than 0,5 mS/m (5 �S/cm) meets this requirement. 5 Apparatus and materials 5.1 Conductometer, with temperature compensation and sufficient range, e.g. from 0 mS/m (0 �S/cm) to 200 mS/m (2 000 �S/cm). 5.2 Glass beaker, of convenient size and shape for housing the electrode end of the conductometer (5.1) during measurement. 5.3 Standard adhesive patch, as specified in 4.1 of ISO 8502-6:1995, e.g. of size A-1250. NOTE The patch should not cause any noticable contamination of the extraction liquid. Certain patches are available today which are guaranteed to cause an ionic contamination of less than 7 mg/m2, which is generally satisfactory. If there is no guarantee or if improved accuracy is required, then a blank test is recommended. 5.4 Syringe, as specified in 4.2 of ISO 8502-6:1995. 6 Procedure 6.1 Preparation of water and blank test 6.1.1 Pour into the beaker (5.2) an amount of water (clause 4) that is just large enough for the operation of the conductometer (5.1). Usually a volume between 10 ml and 20 ml is needed. To prevent foreign matter inside the beaker and syringe, and on the conductometer probe, from influencing the result, carry out the following blank test. 6.1.2 Completely fill the syringe (5.4) with water from the beaker. Then empty the syringe back into the beaker. 6.1.3 Immerse the electrodes of the conductometer fully in the water in the beaker and agitate gently. Record the conductivity (�1) and the units in which it is expressed, for example �S/cm. 6.2 Removal of salts from the steel surface 6.2.1 Follow the procedure specified in clause 5 of ISO 8502-6:1995, subject to the following specific requirements. 6.2.2 Fill the syringe with about one-quarter of the water contained in the beaker. 6.2.3 After 1 min, suck the water back into the syringe cylinder (see 5.6 of ISO 8502-6:1995). 6.2.4 Without removing the syringe needle from the patch, re-inject the water into the patch compartment and then suck the water back into the syringe cylinder. Repeat until 10 cycles of injection and sucking have been completed (see 5.7 of ISO 8502-6:1995). 6.2.5 At the end of the 10th cycle, retrieve as much as possible of the water from the patch compartment and transfer to the beaker (5.2), thus restoring its content to nearly the original volume in 6.1.1 (see 5.8 of 8502-6:1995). 6.3 Conductometric measurement Immerse the electrodes of the conductometer fully in the now contaminated water in the beaker, and record the conductivity (�2) expressed in the same units as in 6.1.3. Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 © BSI 06-2001 3 7 Expression of results The total surface density �A of the salts is given by the equation: where In this case, m is given by ...(1) m is the mass of salts dissolved from that part of the surface which is covered by the patch compartment; A is the area of that part of the surface. m = c. V. �� ...(2) where c is an empirical constant approximately equal to 5 kg�m–2�S–1 (see also clause 8); V is the original volume of water in the beaker (see 6.1.1); �� is the change in conductivity, i.e. the difference between the conductivity measured in 6.3 (�2) and the conductivity measured in 6.1.3 (�1). �A m A -----= Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 4 © BSI 06-2001 Each straight line corresponds to a different volume of water in the beaker. In each case, the patch size is A-1250, in accordance with ISO 8502-6 Figure 1 — The total surface density �A of the salts as a function of the change in conductivity �� Li ce ns ed C op y: In st itu te O f T ec hn ol og y Ta lla gh t, In st itu te o f T ec hn ol og y, F ri M ar 0 2 12 :1 2: 13 G M T+ 00 :0 0 20 07 , U nc on tro lle d Co py , (c ) B SI www.bzfxw.com EN ISO 8502-9:2000 © B