1、Designation: D5064 16D5064 16aStandard Practice forConducting a Patch Test to Assess Coating Compatibility1This standard is issued under the fixed designation D5064; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the procedures for assessing coating compatibility when maintenance of an in-place coating system isbe
3、ing contemplated. It does not address procedures for assessing the integrity of the existing coating to determine if it can berepainted, nor does it establish the compatibility of the maintenance coating system with the substrate or corrosion products. Thepractice is intended for use in the field. S
4、SPC-TU 3 discusses the risks associated with the maintenance painting practice knownas overcoating.NOTE 1Pass-Fail Criteria (for example, adhesion requirements) are not established by this practice. These should be established by the user orspecifier with input from the coating manufacturer.1.2 The
5、values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropri
6、ate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D16 Terminology for Paint, Related Coatings, Materials, and ApplicationsD3359 Test Methods for Measuring Adhesion by Tape TestD4138 Practices for Measureme
7、nt of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-SectioningMeansD4414 Practice for Measurement of Wet Film Thickness by Notch GagesD4541 Test Method for Pull-Off Strength of Coatings Using Portable Adhesion TestersD6132 Test Method for Nondestructive Measurement of Dry Fi
8、lm Thickness of Applied Organic Coatings Using an UltrasonicCoating Thickness GageD6677 Test Method for Evaluating Adhesion by KnifeD7091 Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metalsand Nonmagnetic, Nonconductive Coatings Applied to
9、Non-Ferrous MetalsD7234 Test Method for Pull-Off Adhesion Strength of Coatings on Concrete Using Portable Pull-Off Adhesion Testers2.2 SSPC Standards:3TU 3 Technology Update No. 3 Overcoating3. Terminology3.1 DefinitionsFor definitions of terms used in this practice, refer to Terminology D16.4. Summ
10、ary of Test Method4.1 The materials under test are applied to the previously painted surface after surface preparation. After the appropriate timehas elapsed, the test patch is examined for visual defects and adhesion is assessed.1 This practice is under the jurisdiction of ASTM Committee D01 on Pai
11、nt and Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved July 1, 2016Dec. 1, 2016. Published August 2016December 2016. Originally approved in 1990. Last previous edition approved in 20122016
12、 asD5064 07 (2012).D5064 16. DOI: 10.1520/D5064-16.10.1520/D5064-16a.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM
13、website.3 Available from Society for Protective Coatings (SSPC), 800 Trumbull Drive, Pittsburgh, PA 15205, http:/www.sspc.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becau
14、seit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Ba
15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 In performing maintenance of a coating system, the new coating being applied must be compatible with the existing coating.While general guides exist which indicate compatibility of different gene
16、ric types of coatings, differences in manufacturersformulation and the condition of the in-place coating system may affect compatibility.6. Procedure6.1 Select test locations for evaluation that adequately characterize differences in configuration of the structure and the exposureenvironment; that i
17、s, vertical versus horizontal surfaces; sheltered versus unsheltered exposure; atmospheric verses splash zone orimmersion.Additional factors must be considered for previously immersed areas. For these cases consult the coating manufacturer.A minimum of three test locations with one test patch in eac
18、h is recommended.6.2 The size of each test patch is limited by the size and configuration of the test locations. Each test patch shall be as largeas possible, with a minimum size of 1.0 m2 (10.8 ft2) recommended.6.3 Prepare the surface of the test areas using the methods specified for the maintenanc
19、e painting procedure (Note 2).Alternativemethods of preparation may also be evaluated in separate, adjacent tests.NOTE 2This practice is intended to assess compatibility with the existing coating only and does not apply to areas where the substrate is exposedby the methods of preparation.6.4 Measure
20、 the existing coating thickness in accordance with Test Methods D6132, D4138, or Practice D7091, as appropriatefor the type of substrate.6.5 Measure the air and surface temperatures, the relative humidity and the dew point temperatures and verify that theconditions are within the limits recommended
21、by the coatings manufacturer for the product(s) being tested.6.6 Apply the test coating to the thickness recommended by the coating manufacturer. Use the application technique as intendedfor use during production operations. If agreed upon between the purchaser and the seller, the method of coating
22、application maybe different from that proposed for use on the job, that is, brush application of the test patch even though spray application isintended to be used on the job. However, this can cause anomalies in the data and is not generally recommended.6.7 Immediately after application, measure th
23、e wet-film thickness in accordance with Practice D4414. Inspect each patch forapplication defects such as runs, sags, and pinholes. If such defects cannot be corrected as a part of the initial application process,prepare a new test patch.6.8 After the coating has dried, measure the dry-film thicknes
24、s in accordance with Test Methods D6132, D4138, or D7091.Make corrections to the application, if necessary, by either applying more material if the dry film thickness is low (build-up coat)or applying another test patch if the dry film thickness is above the recommended maximum.NOTE 3When using Test
25、 Method D6132 or Practice D7091, the dry film thickness is the difference in average thickness of the coating system lessthe average thickness of the in-place coating.6.9 Allow the A sufficient test duration and inspection frequency should be agreed upon between the purchaser and seller priorto eval
26、uation. The test duration should be long enough to allow the coating to cure and weather prior to evaluation. CureTestdurations are defined as long term and short term. Long-term curing provides test durations provide the most reliable assessmentof compatibility. Short-term curing provides test dura
27、tions provide for more rapid evaluation of results, but may not reveal allpotential compatibility problems. Test durations longer or shorter than those listed in 6.9.1 and 6.9.2 may be agreed upon betweenthe purchaser and seller.6.9.1 Long-Term CuringTest DurationCuring and weathering for as long a
28、time as possible, with a minimum of six monthspreferred. CuringWeathering should span seasonal weather changes.6.9.2 Short-Term CuringTest DurationCuring and weathering at the following minimum times based on average daily (24h) temperatures:10C (50F) 21C (70F) 32C (90F)14 days 10 days 7 daysLonger
29、minimum cure times are acceptable if manufacturer requires longer minimum cure times.6.10 After curing, the test duration is completed (or at the inspection interval), examine the total surface of each test patch forwrinkling, blistering, mudcracking, checking, cracking, peeling, lifting, and disbon
30、ding. Measure or rate the adhesion in aminimum of five locations per test patch in accordance with Test Methods D3359 or D6677. If agreed upon between the purchaserand the seller, adhesion testing in accordance with Test Methods D4541 or D7234 may be used.6.11 Examine the test patches for the defect
31、s noted in 6.10 on a regular schedule, discounting rust caused by previous tests suchas adhesion measurements and destructive film thickness measurements.7. Report7.1 Report the following information:D5064 16a27.1.1 The identity of the structure tested, the location and size of the test patches, the
32、 identity of the test coating, the methodand grade of surface preparation, and the method of coating application.7.1.2 For each test patch, the dry film thickness measurements and average of the in-place coating, the dry film thicknessmeasurements and average of the test coating, the elapsed time fo
33、r each evaluation, the visual defects noticed, and the results ofadhesion tests.8. Keywords8.1 coating; coating compatibility; coating test patch; paint; paint compatibility; test patchASTM International takes no position respecting the validity of any patent rights asserted in connection with any i
34、tem mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical co
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36、meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Driv
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