1、NACE Standard RP0281-2004 Item No. 21026 THE CORROSION SOC!ETY Stan da rd Recommended Practice Method for Conducting Coating (Paint) Panel Evaluation Testing in Atmospheric Exposures This NACE International standard represents a consensus of those individual members who have reviewed this document,
2、its scope, and provisions. Its acceptance does not in any respect preclude anyone, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE Internati
3、onal standard is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability for infringement of Letters Patent. This standar
4、d represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedures or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific ins
5、tances. NACE International assumes no responsibility for the interpretation or use of this standard by other parties and accepts responsibility for only those official NACE International interpretations issued by NACE International in accordance with its governing procedures and policies which precl
6、ude the issuance of interpretations by individual volunteers. Users of this NACE International standard are responsible for reviewing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE I
7、nternational standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE International standard are also responsible for esta
8、blishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regulatory requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE International stand
9、ards are subject to periodic review, and may be revised or withdrawn at any time without prior notice. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the la
10、test edition. Purchasers of NACE International standards may receive current information on all standards and other NACE International publications by contacting the NACE International Membership Services Department, 1440 South Creek Drive, Houston, Texas 77084-4906 (telephone +I 281 228-6200). Reaf
11、firmed 2004-09-14 Reaffirmed 1998-03-27 Reaffirmed October 1993 Reaffirmed December 1986 Approved June 1981 NACE International 1440 South Creek Drive Houston, Texas 77085-4906 +I (281)228-6200 ISBN 1-57590-069-6 O 2004. NACE International RP0281-2004 Foreword This standard recommended practice provi
12、des guidelines for establishing standardized procedures for selecting coating (paint) test panels, preparing and painting the surfaces of coating test panels, selecting test sites, and grading and evaluating coating test panels in atmospheric exposure. Such standardization procedures are necessary f
13、or meaningful comparisons of coating panel tests. The recommendations in this standard apply only to atmospheric exposure and specifically exclude immersion testing and laboratory testing. Standards and other recommendations relating to the procedures described herein are listed in Appendix D. This
14、standard provides minimum procedural guidelines for all parties concerned with the field performance evaluation of protective coating systems. This standard was originally prepared by NACE Task Group T-6H-25 of Unit Committee T-6H on Coating Materials for Atmospheric Service, and later transferred t
15、o Task Group T-6Q-16 of Unit Committee T-6Q on Quality Assurance of Protective Coating Materials and Their Application. The members of Task Group T-6Q-16 included representatives from consulting firms, users of protective coatings, and coating manufacturers. This standard was editorially updated in
16、1993 and reaffirmed in 1998 by Unit Committee T-6H. It was reaffirmed in 2004 by Specific Technology Group (STG) 02 on Protective Coatings and Linings-Atmospheric. This standard is issued by NACE under the auspices of STG 02. In NACE standards, the terms shall, must, should, and may are used in acco
17、rdance with the definitions of these terms in the NACE Publications Style Manual, 4th ed., Paragraph 7.4.1.9. The terms shall and must are used to state mandatory requirements. The term should is used to state something considered good and is recommended but is not mandatory. The term may is used to
18、 state something considered optional. NACE International I RP0281-2004 NACE International Standard Recommended Practice Cathodic Protection of Prestressed Concrete Cylinder Pipel ines Contents 1. General . 1 2. Purpose of Testing Program 1 3. Coating Test Panel Selection . 1 4. Surface Preparation .
19、 . 5. Panel Preparation . 6. Selection of Exposure Site . . 7. Panel Test Racks . . 8. Coating Test Panel Evaluation . . 9. Processing Field Grading Data . IO. Interpretation of Coating Test Panel Appendix A: Application Record Appendix B: Single-Panel Paint Record Appendix C: Multipanel Paint Inspe
20、ction . . . . . . Appendix D: List of Standards and Othe anel Testing II NACE International RP0281-2004 Section 1: General 1.1 This standard standard provides guidelines for establishing accelerated weathering, salt fog, fume chambers, etc.), they procedures for coating test panel selection, are spe
21、cifically intended for coating test panel evaluation in sutface preparation, coating application, field exposure sites and conditions, and the grading and evaluation of coating test panels. Appendices A, B, and C provide example forms that may be used in conjunction with these recommendations. Appen
22、dix D provides a list of standards and other information related to coating panel testing. 1.2 While many of these recommendations may be appropriate for testing in other environments (such as an atmospheric exposure. These recommendations are not intended to be used for laboratory testing, immersio
23、n testing, etc. 1.3 Preliminary screening of coating systems may be more efficiently and economically accomplished by laboratory testing. Also, superior petformance of a coating system on a coating test panel in an atmospheric environment does not ensure that equivalent petformance will be attained
24、during actual field application and service. Section 2: Purpose of Testing Program 2.1 The purpose of a test program should be clearly gradings should always be done with the purpose of the test detailed prior to the establishment of test procedures. The choice of coating test panel, sutface prepara
25、tion, coating application methods, grading methods, and interpretation of 2.2 Written procedures and/or instructions should be program in mind. provided. Section 3: Coating Test Panel Selection 3.1 The coating test panel should be fabricated from the same material over which the coating is expected
26、to petform in field service. For structural steel, this should be American Iron and Steel Institute (AISI)() NI020 hot-rolled carbon steel. A 1.6-mm (0,063-in.) minimum thickness should be maintained to prevent deformation during blast cleaning. The panel may have a lesser thickness if it is not bla
27、st cleaned. The panel should have a 13-cm (5.0-in.) minimum length and a 7.6-cm (3.0-in.) minimum width. 3.2 The variety of sizes and shapes of commercially available coating test panels can be divided into two categories: flat panels and composite panels. 3.2.1 A flat panel should be uniform with n
28、o sutface irregularity. Variations in petformance properties such as rusting, loss of gloss, and chalking as a result of formulation variables are best evaluated if coating is applied over a flat coating test panel. This type of sutface minimizes the effect of application variables. 3.2.2 A composit
29、e coating test panel should be specially fabricated to include welds, sharp angles, crevices, and other hard-to-coat sutface irregularities. Composite coating test panels are commonly used to evaluate a coating system over irregularities similar to those encountered during the coating of structural
30、steel. 3.3 The same type of coating test panel shall be used for comparative evaluation of all candidate coating systems. Section 4: Surface Preparation 4.1 Sutface preparation of coating test panels should be that expected to be done in the field. Because of possible variations in uniformity of bla
31、st cleaning, testing is Sutface Preparation Section, for additional information). commonly done on panels cleaned to a white metal sutface in accordance with NACE No. 1/SSPC(2)-SP 5, particularly if small coating test panels are used (see Appendix D, (I American Iron and Steel Institute (AISI), 1140
32、 Connecticut Ave., NW, Suite 705, Washington, DC 20036 SSPC: The Society for Protective Coatings, 40 24” Street, Sixth Floor, Pittsburgh, PA 15222-4656. NACE International 1 RP0281-2004 4.2 If testing over rusty sutfaces, the coating test panels should preferably be prerusted (weathered) in the same
33、 environment in which they will ultimately be exposed. Alternatively, prerusting in a laboratory or an environment different from that of the intended exposure may be done. 4.3 The sutface profile shall be the same for all coating test panels unless it is a variable to be evaluated. When blast clean
34、ing, the same cleaning conditions (.e., abrasives, blast angles, nozzle pressures, distances, and/or wheel velocities for rotary wheel blast cleaning) shall be used for each coating test panel. 4.4 After sutface preparation, the panels must be prime coated as soon as possible to prevent flash rustin
35、g or deposition of foreign contaminants on the cleaned sutface. If the panels are stored prior to coating, precautions must be taken to preserve the clean sutface after sutface preparation. 4.5 The following recommended storage methods should be used: 4.5.1 Temperature should be raised to 71 to 82C
36、(1 60 to 180”F), and relative humidity should be reduced using a lamp or oven. 4.5.2 Desiccation/humidity control should be used to reduce humidity. Relative humidity shall be maintained at 30%. 4.5.3 Solvent immersion should be used to exclude moisture and/or oxygen from the coating test panel sutf
37、ace. Care must be taken to ensure that no oily residues remain after coating test panel removal and solvent evaporation (clean mineral spirits are commonly used). 4.5.4 Vapor-phase inhibitor paper, a chemically treated paper, should be wrapped around the panel to inhibit corrosion. 4.6 When handling
38、 coating test panels after sutface preparation and during coating, precautions must be taken to avoid touching or contaminating the surface. Section 5: Panel Preparation 5.1 Coatings are formulated for application by a variety of methods (e.g., airless or conventional spray, brushing, roller coating
39、, etc.). If a coating is formulated to be applied in a specific manner, it should not be applied by other means. All application shall be done in strict accordance with the coating manufacturers written recommendations. The method of application to be used during field application should also be use
40、d for coating test panel application, although special procedures may be necessary because of panel size or configuration. Coating application may be done in either the laboratory or field area of intended use (see Appendix A). 5.2 Ambient Conditions 5.2.1 The following ambient conditions shall be m
41、easured and recorded during application and curing of the coating test panels: air and sutface temperature, humidity, dew point, and, if coating outside, wind, rain, and other pertinent weather information. All coating test panels shall be coated under the same ambient conditions. 5.3.2 The applicat
42、ion equipment must be clean and, if compressed air is used, free of water, oil, and other contaminants. If a spray application is specified, the fan should be narrowed to 3.8 to 5.1 cm (1.5 to 2.0 in.) for smaller coating test panels to simulate laps. At least one lap shall be made (see Appendix D,
43、Coating Application Section). 5.4 Drying and Cure Time 5.4.1 The drying time between coats should meet the recommendations of the coating manufacturer. The drying or cure time after application and prior to exposure should ideally be the same as that normally encountered in field service, which usua
44、lly begins immediately after application. However, because coating thickness must be accurately measured, the edges and backside must be further protected and, if required, the panel scribed, impacted, and then installed in a test rack. A minimum of seven days should be allowed for final dry and cur
45、e prior to handling for the above purposes. 5.3 Coating Application 5.5 Scribe and Impact 5.3.1 The coating application should be done by a trained applicator, preferably an individual skilled in coating test panels. 5.5.1 Coating test panels may be scribed. Other means of inflicting intentional dam
46、age to the coating may also be used. If this is done, the same procedures must be used for all coating test panels. A recommended scribing procedure is ASTM3 D 1654. . 3ASTM International (ASTM), 1 O0 Barr Harbor, West Conshohocken, PA 19428-2959 NACE International RP0281-2004 5.6 Coating Thickness
47、5.6.1 Coating thickness may be determined by a number of instruments and techniques; however, the same method shall be used for all coating test panels. 5.6.2 There should be at least one thickness determination for each 97 cm2 (15 in.2) of panel surface. Each thickness determination shall consist o
48、f an average of at least three measurements in a given area. No panel shall have less than three thickness determinations (see Appendix D). 5.7 Thickness Variation for Specification 5.7.1 When applying coatings, it is difficult to obtain an exact specified thickness. However, a trained applicator sh
49、ould be able to obtain a I25% thickness deviation per coat, and remain within -10% to +20% of the minimum specified total coating thickness. If it is found that the applied coating is not within the recommended range, a new coating test panel must be prepared. In no case shall the thickness be beyond the range recommended by the manufacturer. 5.7.2 As different generic types of coatings build to different thicknesses, the number of coats and the thickness per coat for the total coating system should be that recommended by the coating manufacturer. NOTE: In some cases, coatings
