ASTM_D_714_-_02_2009.pdf

Designation:D71402(Reapproved 2009)Standard Test Method forEvaluating Degree of Blistering of Paints1This standard is issued under the fixed designation D714;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year 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 Department of Defense.1.Scope1.1 This test method employs photographic reference stan-dards to evaluate the degree of blistering that may developwhen paint systems are subjected to conditions which willcause blistering.While primarily intended for use on metal andother nonporous surfaces,this test method may be used toevaluate blisters on porous surfaces,such as wood,if the sizeof blisters falls within the scope of these reference standards.When the reference standards are used as a specification ofperformance,the permissible degree of blistering of the paintsystem shall be agreed upon by the purchaser and the seller.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It 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 Adjuncts:Reference Standards for Blistering of Paint Coatings23.Significance and Use3.1 A phenomenon peculiar to painted surfaces is theformation of blisters relative to some system weakness.Thistest method provides a standard procedure of describing thesize and density of the blisters so that comparisons of severitycan be made.4.Reference Standards4.1 The photographic reference standards are glossyprints.2Figs.1-4 are reproductions of these standards and areincluded to illustrate two characteristics of blistering:size andfrequency.4.2 SizeReference standards have been selected for foursteps as to size on a numerical scale from 10 to 0,in which No.10 represents no blistering.Blistering standard No.8 representsthe smallest size blister easily seen by the unaided eye.Blistering standards Nos.6,4,and 2 represent progressivelylarger sizes.4.3 FrequencyReference standards have been selected forfour steps in frequency at each step in size,designated asfollows:Dense,D,Medium dense,MD,Medium,M,andFew,F.NOTE1Aquantitative physical description of blistering would includethe following characteristics determined by actual count:Size distribution in terms of mensuration units,Frequency of occurrence per unit area,Pattern of distribution over the surface,andShape of blisterFor the usual tests,an actual count is more elaborate than is necessary.5.Procedure5.1 Subject the paint film to the test conditions agreed uponby the purchaser and the seller.Then evaluate the paint film forthe degree of blistering by comparison with the photographicreference standards in Figs.1-4.6.Report6.1 Report blistering as a number(Note 2)designating thesize of the blisters and a qualitative term or symbol indicatingthe frequency.6.2 Intermediate steps in size or frequency of blisters maybe judged by interpolation.6.3 When the distribution of blisters over the area has anonuniform pattern,use an additional phrase to describe thedistribution,such as“small clusters,”or“large patches.”NOTE2The number refers to the largest size blister that is numerousenough to be representative of the specimen.For example,photographicstandard No.4,“Dense,”has blisters ranging in size from about No.7 toNo.4,inclusive.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.25 on Evaluation of Weathering Effects.Current edition approved July 1,2009.Published July 2009.Originally approvedin 1943.Last previous edition approved in 2002 as D714021.DOI:10.1520/D0714-02R09.2Glossy prints of the photographic reference standards showing types ofblistering are available from ASTM International Headquarters.Order Adjunct No.ADJD0714.Original adjunct produced in 1986.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.4 The pictorial representations in this standard which arepublished in the Book of Standards are sufficient in order toconduct the evaluation.It is preferable however,to use theoriginal photographs or drawings when available.7.Keywords7.1 blistering;corrosion;evaluations;reference standardsFewMediumFIG.1 Blister Size No.2Medium DenseDenseFIG.1(continued)D714 02(2009)2 FewMediumFIG.2 Blister Size No.4Medium DenseDenseFIG.2(continued)D714 02(2009)3 FewMediumFIG.3 Blister Size No.6Medium DenseDenseFIG.3(continued)D714 02(2009)4 FewMediumFIG.4 Blister size No.8Medium DenseDenseFIG.4(continued)D714 02(2009)5 ASTM International takes no position respecting the validity of any