ASTM_D_344_-_11_2016.pdf

Designation:D34411(Reapproved 2016)Standard Test Method forRelative Hiding Power of Paints by the Visual Evaluation ofBrushouts1This standard is issued under the fixed designation D344;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 test method provides for the qualitative and quan-titative visual determination of the hiding power of a test paintrelative to that of a comparison paint.1.2 This test method describes only a brushout applicationprocedure in specific detail,but its concepts are valid for othermethods of application as well.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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:2D16 Terminology for Paint,Related Coatings,Materials,andApplicationsD1475 Test Method For Density of Liquid Coatings,Inks,and Related ProductsD1729 Practice for Visual Appraisal of Colors and ColorDifferences of Diffusely-Illuminated Opaque MaterialsD2805 Test Method for Hiding Power of Paints by Reflec-tometryD5068 Practice for Preparation of Paint Brushes for Evalu-ationE1247 Practice for Detecting Fluorescence in Object-ColorSpecimens by SpectrophotometryE1347 Test Method for Color and Color-Difference Mea-surement by Tristimulus ColorimetryE1349 Test Method for Reflectance Factor and Color bySpectrophotometry Using Bidirectional(45:0 or 0:45)Geometry3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology D16 and the Paint/CoatingsDictionary.33.2 Definitions of Terms Specific to This Standard:3.2.1 relative hiding power,qualitative,nthe characteriza-tion of a test paint as being better,equal,or poorer in hidingpower than a comparison paint.3.2.2 relative hiding power,quantitative,nthe spreadingrate of a paint expressed as a percent of the spreading rate ofa comparison paint at equal hiding.4.Summary of Test Method4.1 QualitativeThe test and comparison paints arebrushed out uniformly at the same spreading rate on black andwhite hiding power charts.After drying the brushouts arecompared visually to see which paint has been most effectivein reducing the substrate contrast.4.2 QuantitativeAdditional brushouts are made with thecomparison paint,if and as necessary,to determine the spread-ing rate at which it matches the hiding of the test paintbrushout.5.Significance and Use5.1 This test method evaluates the hiding power of a testpaint relative to a comparison paint.The results have signifi-cance only within that relationship.It may be used forproduction control or quality comparisons.5.2 When a paint is applied by brush or any other practicalmethod,the opacity of the film is affected by variations in filmthickness related to the application procedure and to theapplication characteristics of the paint.Two paints that hideequally well by this method might therefore differ considerablywhen applied with a doctor blade,since the latter method gives1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.26 on Optical Properties.Current edition approved Dec.1,2016.Published December 2016.Originallyapproved in 1932.Last previous edition approved in 2011 as D344 11.DOI:10.1520/D0344-11R16.2For 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.3Available from American Coatings Association(ACA),1500 Rhode IslandAve.,NW,Washington,DC 20005,http:/www.paint.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 essentially perfect leveling.Different brushes or surface appli-cation conditions can likewise give different results.NOTE1Test Method D2805 describes an instrumental method forquantitatively determining hiding power without reference to a materialpaint standard.The paint film is applied at a uniform thickness(forexample,with a doctor blade),the film thickness is measured rigorously,and the opacity is evaluated photometrically.Hiding power is therebydetermined with a high degree of precision.5.3 Test Method D344 is less precise than Test MethodD2805,but is more practical because it is responsive to theapplication characteristics of paints,and is simpler in conceptand execution.6.Apparatus6.1 Balance,t