1、Designation: D3258 04 (Reapproved 2010)1Standard Test Method forPorosity of White or Near White Paint Films by Staining1This standard is issued under the fixed designation D3258; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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() indicates an editorial change since the last revision or reapproval.1NOTESection 2 and 4.3 Test Method E97 was withdrawn and replaced by Test Method E1347 in June 2010.1. Scope1.1 This test
3、method covers the determination of the poros-ity of a white or near white mineral spirits insoluble paint filmto indicate the degree to which a subsequent coat will pen-etrate.1.2 The texture of the film can affect cleanup that willinfluence the results of the test. A stain applied to a high-hidingp
4、aint will not lower the reflectance as much as the same stainapplied to a low-hiding paint of equal porosity. These pointsmust be considered in comparing different paints.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4
5、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 Docum
6、ents2.1 ASTM Standards:2E1347 Test Method for Color and Color-Difference Mea-surement by Tristimulus Colorimetry3. Summary of Test Method3.1 The test paint is applied to a nonporous surface, airdried, then measured for reflectance. A special colored pen-etrating medium is applied, the excess removed
7、 in a specifiedmanner, and reflectance measured again. The difference be-tween the two readings indicates the degree of porosity; thesmaller the difference, the lower the porosity of the film and thegreater its ability to resist penetration.4. Apparatus and Materials4.1 Film Applicator, 150 mm (6 in
8、.) wide with a clearanceof 300 m (12 mils).4.2 Film Applicator, 140 mm (512 in.) wide with a clearanceof 250 m (10 mils).4.3 Reflectometer, meeting the requirements of Test MethodE1347.4.4 Vacuum Drawdown Plate.4.5 Camelhair Brush (approximately 13 mm (12 in.) wide).4.6 Plastic Wash Bottle, containi
9、ng odorless mineral spirits(about 500 mL (16 oz).4.7 Test PanelSmooth nonporous panel such as sealedwhite, cardboard chart, or white plastic sheet.4.8 Penetrating MediumA composition of pigment anddark-colored dye dispersed in organic liquid vehicle.4.9 Filter Paper.5. Procedure5.1 Place the test pa
10、nel on the vacuum plate and apply thepaint under test with the 30-m (12-mil) clearance drawdownblade. Remove the test panel from the vacuum plate and air dry48 h under standard conditions of 23 6 2C (73 6 3.5F) and50 6 5 % relative humidity.5.2 Determine the percent reflectance of the dry film using
11、the green filter on the reflectometer. When making this reading,back up the panel with a flat rigid opaque object and mark thearea on which the reading was made.5.3 Place the panel containing the dry paint film on thevacuum plate. Using the 25-m (10-mil) clearance blade, applythe penetrating medium
12、over the test paint, covering the areamarked as above and drawing the applicator blade in the samedirection as before.5.4 After 5 min 6 15 s wash off excess penetrating medium.To do this, hold the panel vertically and remove the mediumusing the camelhair brush wet with odorless mineral spirits.Repea
13、t the process until most of the excess is removed. Thencontinue to remove more of the excess by applying mineralspirits directly from the wash bottle to the area above the stainso that it flows across the stained area. Pause to observe thebead that forms at the bottom of the panel. If the bead is no
14、t1This 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 June 1, 2010. Published July 2010. Originally approvedin 1973. Last p
15、revious edition approved in 2004 as D3258 04. DOI: 10.1520/D3258-04R10E01.2For 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
16、ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.clear, continue washing with mineral spirits until the bead isessentially clear. Test with filter paper to be sure no dyeremains in the bead.5.5 Hang the panel in a vertica
17、l position and air dry for 3 h.As before, read the percent reflectance over the same area ofthe panel with the same flat rigid opaque object behind thepanel.6. Report6.1 Report the difference between the percent reflectance ofthe untested film and that of the penetrated film.7. Precision7.1 On the b
18、asis of an interlaboratory study of this testmethod in which one operator in each of ten laboratories testedpaint films of two nominally different levels of porosity, thewithin-laboratory and between-laboratories standard devia-tions were found to be:Nominal Differencein Reflectance, %Standard Devia
19、tionsWithin-Laboratory Between-Laboratories7 0.27 1.2635 0.60 4.22Based on these standard deviations the following criteriashould be used to judge the precision or results at the 95 %confidence level:7.1.1 RepeatabilityDuplicate results, obtained by a singleoperator, should be considered suspect if
20、they differ by morethan 0.8 % relative for difference in reflectance levels of about7 % and more than 1.8 % relative for difference in reflectancelevels of about 35 %.7.1.2 ReproducibilityTwo results, each the mean of dupli-cate measurements obtained in different laboratories should beconsidered sus
21、pect if they differ by more than 4.0 % relativefor difference in reflectance levels of about 7 % and 14 %relative for difference in reflectance levels of about 35 %.8. Keywords8.1 film porosity; porosity; resistancepenetration (intopaint films)ASTM International takes no position respecting the vali
22、dity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subj
23、ect to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquar
24、ters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standar
25、d is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3258 04 (2010)12
