1、Designation:D748909(Reapproved 2017)Standard Practice forEvaluating Touch-Up Properties of Architectural Coatingsunder Various Environmental Conditions1This standard is issued under the fixed designation D7489;the number immediately following the designation indicates the year oforiginal adoption or
2、,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.1.Scope1.1 This practice determines the ability of a paint to berecoated or“touched up”in small a
3、reas.Variations in color,gloss,and sheen that result in a different appearance from theoriginal paint can be evaluated visually.1.2 This practice describes evaluation of touch-up charac-teristics in a laboratory-scale controlled environment as op-posed to a full-scale field environment.1.3 Evaluatio
4、n of touch-up properties under constant dryingconditions is described.Environmental conditions can beadjusted to incorporate high or low temperature drying,orboth.The changes in application temperature can lead to largerdifferences in touch-up than applying both coats under thesame environmental con
5、ditions.1.4 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.1.5 This i
6、nternational standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)
7、Committee.2.Referenced Documents2.1 ASTM Standards:2D344 Test Method for Relative Hiding Power of Paints bythe Visual Evaluation of BrushoutsD523 Test Method for Specular GlossD1475 Test Method For Density of Liquid Coatings,Inks,and Related ProductsD1729 Practice for Visual Appraisal of Colors and
8、ColorDifferences of Diffusely-Illuminated Opaque MaterialsD5068 Practice for Preparation of Paint Brushes for Evalu-ationD5069 Practice for Preparation of Paint-Roller Covers forEvaluation of Architectural CoatingsD6762 Test Method for Determining the Hiding Power ofPaint by Visual Evaluation of Spr
9、ay Applied CoatingsE1347 Test Method for Color and Color-Difference Mea-surement by Tristimulus Colorimetry3.Terminology3.1 Definitions:3.1.1 touch-up,nto repair visual differences in a paintedsurface by recoating small areas with the same paint that wasused for the original coat.3.1.1.1 DiscussionT
10、his includes color and sheen differ-ences in the dry film.4.Summary of Practice4.1 Paints,application tools,and drying conditions areselected before starting this practice.Relevant color(s)fortesting and any specific primers should also be selected at thistime.4.2 Multiple coats of the test paint ar
11、e applied to a specifiedsubstrate in a prescribed manner to simulate touch-up condi-tions.The results are visually evaluated for variations in color,gloss,and sheen between the touch-up coating and the first andsecond coat.4.3 A qualitative rating scale for the touch-up result isdescribed.5.Signific
12、ance and Use5.1 During construction of a home,paints are subjected to awide variety of drying conditions,and this may exhibitdifferences between the original coat and the touched-up areain appearance after its full cure.Therefore,it it essential for thepaint to be able to perform under a wide variet
13、y of dryingconditions.A paint that does this is very advantageous to thecontractor.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.42 on Architectural Coatings.Current edition a
14、pproved June 1,2017.Published June 2017.Originallyapproved in 2009.Last previous edition approved in 2013 as D7489 09(2013).DOI:10.1520/D7489-09R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards v
15、olume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standard
16、ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 5.2 It is possible for a paint to have excellent color touch-up,but poor sheen touch-up,or vice-versa.The ideal paint willhave both excellent color and sheen touch-up under testingconditions.5.3 Color,gloss and base choice can have a major impact ontouch-up of the paint.6.Apparatus and Materia
