1、Designation:D421407(Reapproved 2015)Standard Test Methods forEvaluating the Degree of Chalking of Exterior Paint Films1This standard is issued under the fixed designation D4214;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、 of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover the evalu
3、ation of the degree ofchalking on white or tinted exterior paint films.These testmethods describe the procedures recommended for transferringthe chalk to a fabric or fingertip,which is then compared tophotographic reference standards,or in the case of adhesivetapes,compared to a reflectance table or
4、 photographic refer-ence standards,to determine the degree of chalking.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It
5、 is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D662 Test Method for Evaluating Degree of Erosion ofExterior PaintsE1347 Test Met
6、hod for Color and Color-Difference Mea-surement by Tristimulus Colorimetry2.2 Other Document:Pictorial Standards of Coating Defects33.Terminology3.1 Definitions:3.1.1 chalking,nthe formation on a pigmented coating ofa friable powder evolved from the film itself at or just beneaththe surface.4.Signif
7、icance and Use4.1 The procedures provide a broad range of techniques andphotographic references to evaluate chalking of exterior paints.5.Type of Chalking5.1 Only one type of chalking is recognized,as defined inSection 3.6.Use of Photographic Reference Standards6.1 The photographic reference standar
8、ds that are part ofthese test methods are representative of the degrees of chalkingon a paint film.The photographs shown in Fig.1 and Fig.2 arefor illustration purposes only and should not be used forevaluation.6.2 The use of photographic reference standards illustratedin Fig.1 and Fig.2 requires th
9、e following precautions:6.2.1 The degree of chalking will vary over any given area.Therefore,an average portion of the coating should be evalu-ated.On large surfaces,it is recommended that the rating bemade at several locations and the mean and range reported.6.2.2 It is difficult to make readings o
10、n a windy day andmaking readings at such time should be avoided.It should alsobe noted that rain,snow,or moisture in any form will removechalk so that readings should be made after a period of clearweather and when the surface is dry.6.2.3 Chalking and erosion(Note 1)are closely related.However,the
11、rate of chalking as measured by these testmethods,and the rate of erosion may not be comparablebecause some pigment combinations tend to retain chalk on thesurface while other pigment combinations exert a self-cleaningaction by natural means.NOTE1For the evaluation of erosion,see Test Method D662.6.
12、3 Records may be kept on forms4such as shown in Fig.3.Reporting of the results shall include the information given inSection 8.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee
13、 D01.25 on Evaluation of Weathering Effects.Current edition approved June 1,2015.Published June 2015.Originallyapproved in 1982.Last previous edition approved in 2007 as D4214 07.DOI:10.1520/D4214-07R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Servic
14、e at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Copies of the pictorial photographic reference standards applicable to TestMethod A are contained in the publication Pictorial Standards of Coatings Defectsand ma
15、y be obtained from the Federation of Societies for Coatings Technology,492Norristown Rd.,Blue Bell,PA 19422.4These record sheets may be obtained from the Federation of Societies forCoatings Technology,492 Norristown Rd.,Blue Bell,PA 19422.Copyright ASTM International,100 Barr Harbor Drive,PO Box C70
16、0,West Conshohocken,PA 19428-2959.United States1 6.4 When these test methods is referenced in specificationsfor performance,the permissible degree of chalking is estab-lished between the producer and the user.7.Recommended Procedures7.1 Test Method ACloth Tape Method:7.1.1 MaterialFabric,as agreed upon between theproducer,user,or other interested parties,to rub against thesurface being tested.Black(or white for dark coatings)woolfelt,velvet,and velveteen have proven particularly effective.7.1.2
