1、Designation:D389108(Reapproved 2014)Standard Practice forPreparation of Glass Panels for Testing Paint,Varnish,Lacquer,and Related Products1This standard is issued under the fixed designation D3891;the number immediately following the designation indicates the year oforiginal adoption or,in the case
2、 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 covers the preparation of glass panels forsubsequent testing of paint,varnish,lacque
3、r,and relatedproducts.21.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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 standa
4、rd 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:3D1152 Specification for Methanol(Methyl Alcohol)D1193 Specification for Reagent Water3.Significance and Use3.1 The procedures des
5、cribed in this practice are designed toprovide uniform glass panels for testing of paint,varnish,lacquer,conversion coatings and related products.4.Reagents and Materials4.1 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Type IV of
6、 Specification D1193.4.2 SolventsVarnish Makers and Painters(VM&P)naphtha,xylene,2-methoxypropanol,and methanol complyingwith the appropriate specifications(see Specification D1152).4.3 Glass of the following types may be specified in theapplicable test methods:4.3.1 Window Glass,(float glass)the su
7、rface of which isplain and free of irregularities.NOTE1Float glass is the most common kind of glass used forwindows.It is produced by floating a ribbon of red hot glass on a bath ofmolten tin.The sides of the float glass exposed to tin and to air havesomewhat different characteristics.The tin side c
8、ontains tin diffused intothe glass structure.Paint generally releases more easily from the tin side,but it may be contaminated with tin,which could affect chemical analysis.Paint generally adheres better to the air side.The sides can be distin-guished by exposing the glass to a UV-A light(“black lig
9、ht”):the air sidewill appear clear,and the tin side will appear frosted.Depending on theapplication,the user may want to choose which side is appropriate for thattest,and make sure that the same side is coated on every panel.Notehowever,that if the window glass used is not float glass(for example,pl
10、ate glass),both sides of the glass will be the same.4.3.2 Clear Plate Glass,not less than 5 mm thick.4.3.3 Plate Glass that has been ground uniformly on oneside with 1F carborundum.4.3.4 Black Structural Glass,one side of which has beenpolished to a smooth,high-gloss surface.4.3.5 White Structural G
11、lass,one side of which has beenpolished to a smooth,high gloss.5.Method of Preparation5.1 New PanelsUsing a clean lintless cloth,wipe thepanel with a solvent mixture consisting of equal volumes ofVM&P naphtha and xylene or of 3 volumes of VM&P naphthaand 1 volume of 2-methoxypropanol or with water.W
12、hen allsoluble and loosely adhering soil has been washed off,flushwith clean solvent.Allow panels to dry at room temperature orforce dry at a temperature no higher than 150C(302F).Aftercooling to room temperature,rub with a clean lintless cloth ifnecessary.5.1.1 The surface after cleaning shall be w
13、ater-break free.This is determined by momentarily immersing in reagent waterone panel of each twenty prepared.If a continuous water filmis not retained(that is,the water film breaks),immerse thepanel in methyl alcohol to obtain a water-break-free surface.After removal,dry at a temperature of 50 to 9
14、5C(122 to203F)and allow to cool before coating or storing.5.1.2 Other combinations or organic reagents that willproduce a surface equal in cleanliness to the solvent mixtures1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is
15、the direct responsibility ofSubcommittee D01.27 on Accelerated Testing.Current edition approved Jan.1,2014.Published January 2014.Originallyapproved in 1980.Last previous edition approved in 2008 as D3891 08.DOI:10.1520/D3891-08R14.2This practice is intended to be equivalent to Method 2021 of U.S.Fe
16、deral TestMethod Standard 141.3For 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 mentioned in 5.1 may be used if agreed upon between thepurchaser and the supplier.5.2 Used PanelsRemove the old paint,using a
