ASTM_D_7489_-_09_2013.pdf

Designation:D748909(Reapproved 2013)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,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 areas.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 Evaluation 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 conditions.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.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 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 Spray 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 DiscussionThis 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 are 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.Significance 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 variety of dryingconditions.A paint that does this is very advantageous to thecontractor.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.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 approved July 1,2013.Published July 2013.Originally approvedin 2009.Last previous edition approved in 2009 as D7489 09.DOI:10.1520/D7489-09R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume 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 States1 5.3 Color,gloss and base choice can have a major impact ontouch-up of the paint.6.Apparatus and Materials6.1 Tinted Test Paint.6.2 Dry Wall Panels,Upson Board,or other acceptedmaterial.Minimum size 30 by 30 cm(1 ft by 1 ft).6.3 Primary Applicator,which could be:6.3.1 Good quality paint roller with38in.nap.6.3.2 Airless spray unit capable of 1000 to 3000 psi andappropriate spray tip.NOTE1If using an airless spray unit,typically a larger test panel isrequired.6.3.3 Other applicators,as agreed upon.6.4 Secondary Applicator,which could be:6.4.1 Good quality paint roller with 1 cm(38in.)nap.6.4.2 Good quality polyester/nylon paint brush.6.4.3 A natural or synthetic sponge.6.4.4 Other applicators,as agreed upon.6.5 Controlled Temperature D