1、Designation:D392800a(Reapproved 2014)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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Summary of Test Method2.1 Paint is brush applied to a test pa
6、nel 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 are applied to large flat surfaces s
7、uch 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 surface.3.2 Thickness is also affected
8、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 Both buyers and sellers are intereste
9、d 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.Apparatus4.1 Paint Brush2,50 mm(2 i
10、n.)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.Reagents and Materials5.1 Laminated
11、 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 beincluded with the test paints as a cont
12、rol,unless the paints areonly ranked.6.Procedure6.1 Apply the latex primer by spray to the entire face of asmooth side of the test panel so as to coat it uniformly at aspreading rate of about 11 m2/gal/L(450 ft2).6.2 Air dry at least 18 h under standard conditions of 23 62C(73.5 6 3.5F)and 50 6 5%re
13、lative humidity andexamine the panel for uniformity of primer application.If this1This 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
14、approved Dec.1,2014.Published December 2014.Originallyapproved in 1980.Last previous edition approved in 2010 as D3928 00a(2010).DOI:10.1520/D3928-00AR14.2The 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.Ifyo
15、u are aware of 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,W
16、hite(for Gypsum Wallboard).Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 appears satisfactory,divide the coated area into sections A andB as shown in Fig.1.6.3 Mount the panel vertically and position it as shown inFig.1 with Section A to the right and Section B to the left ofthe operator.Before painting,wet the brush with water if latexpaints are to be tested or VM&P naphtha if the test paints aresolvent reducible.Shake out as much
