1、Designation:D392800a(Reapproved 2018)Standard Test Method forEvaluation of Gloss or Sheen Uniformity1This standard is issued under the fixed designation D3928;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.
2、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 covers the determination of the unifor-mity of gloss or sheen of a paint applied by brush to a test panelsimulating an i
3、nterior wall section.Variations in gloss or sheenthat may be caused by short wet edge time,poor leveling,andpigment orientation or flotation during and after application areevaluated visually.1.2 Because both the application and the panel evaluationare very subjective,this test method should be used
4、 only forcomparative testing within one laboratory as the ratings as-signed by different laboratories do not usually agree(see 8.1).1.3 The values given in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 This standard does not purport to address
5、 all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in
6、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)Committee.2.Summary of Test Method2.1 P
7、aint is brush applied to a test panel using proceduresand conditions that are most likely to cause nonuniformity ofgloss or sheen.The dry film is then viewed under conditionsthat accentuate variations in gloss or sheen and the overallappearance is evaluated.3.Significance and Use3.1 When coatings ar
8、e applied to large flat surfaces such aswalls,the film thickness may vary or there may be small areasmissed entirely(holidays)when the color of the fresh materialand the previous film are very similar.It is much less costly ifthese areas can be touched up instead of having to repaint theentire surfa
9、ce.3.2 Thickness is also affected in the locations where an areacoated a short time before is joined with the area currentlybeing coated(laps).An application technique that may affectthe final appearance of the film is brushing or rolling thematerial in different directions in adjacent areas.3.3 Bot
10、h buyers and sellers are interested in determiningwhether a coating can be applied without exhibiting areas thatdiffer in appearance because of laps and brush or roller marks,and whether it can be readily touched up to provide a uniformappearance in regard to gloss or sheen and all other aspects.4.A
11、pparatus4.1 Paint Brush,250 mm(2 in.)wide with polyesterfilaments 70 mm(234in.)long,chisel tip 15 mm(916in.)thick.Previously used brushes are preferred.4.2 Paint Brush,25 mm(1 in.)wide with polyester fila-ments 57 mm(214in.)long,chisel tip 10 mm(716in.)thick.Previously used brushes are preferred.5.R
12、eagents and Materials5.1 Laminated Fiber Board,610 by 300 mm(24 by 12 in.)with at least one smooth side.5.2 Latex-Base Primer.35.3 Control Paint(optional)Since there are no standardpanels,photographs,or paints for this test method,an agreed-upon paint of known uniformity of appearance should beinclu
13、ded with the test paints as a control,unless the paints areonly ranked.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.42 on Architectural Coatings.Current edition approved J
14、une 1,2018.Published June 2018.Originallyapproved in 1980.Last previous edition approved in 2014 as D3928 00a(2014).DOI:10.1520/D3928-00AR18.2The sole source of supply of a polyester brush No.B-20CS,known to thecommittee at this time is The Leneta Co.,15 Whitney Rd.,Mahwah,NJ 07430.Ifyou are aware o
15、f alternative suppliers,please provide this information to ASTMInternational Headquarters.Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.3Similar to U.S.Federal Specification TT-P-650c Primer Coating Latex Base,White(for Gyps
16、um Wallboard).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 standardization 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 6.Procedure6.1 Apply the latex primer by spray to the entire f
