1、Designation: D 7489 09Standard Practice forEvaluating Touch-Up Properties of Architectural Coatingsunder Various Environmental Conditions1This standard is issued under the fixed designation D 7489; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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 determines the ability of a paint to berecoated or “touched up” in small area
3、s. Variations in color,gloss, and sheen that result in a different appearance from theoriginal paint can be evaluated visually.1.2 This practice describes evaluation of touch-up charac-teristics in a laboratory-scale controlled environment as op-posed to a full-scale field environment.1.3 Evaluation
4、 of touch-up properties under constant dryingconditions is described. Environmental conditions can beadjusted to incorporate high or low temperature drying , orboth. The changes in application temperature can lead to largerdifferences in touch-up than applying both coats under thesame environmental
5、conditions.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. R
6、eferenced Documents2.1 ASTM Standards:2D 344 Test Method for Relative Hiding Power of Paints bythe Visual Evaluation of BrushoutsD 523 Test Method for Specular GlossD 1475 Test Method For Density of Liquid Coatings, Inks,and Related ProductsD 1729 Practice for Visual Appraisal of Colors and ColorDif
7、ferences of Diffusely-Illuminated Opaque MaterialsD 5068 Practice for Preparation of Paint Brushes for Evalu-ationD 5069 Practice for Preparation of Paint-Roller Covers forEvaluation of Architectural CoatingsD 6762 Test Method for Determining the Hiding Power ofPaint by Visual Evaluation of Spray Ap
8、plied CoatingsE 1347 Test Method for Color and Color-Difference Mea-surement by Tristimulus Colorimetry3. Terminology3.1 Definition:3.1.1 touch-up, nto repair visual differences in a paintedsurface by recoating small areas with the same paint that wasused for the original coat.3.1.1.1 DiscussionThis
9、 includes color and sheen differ-ences in the dry film.4. Summary of Practice4.1 Paints, application tools, and drying conditions areselected before starting this practice. Relevant color(s) fortesting and any specific primers should also be selected at thistime.4.2 Multiple coats of the test paint
10、are applied to a specifiedsubstrate in a prescribed manner to simulate touch-up condi-tions. The results are visually evaluated for variations in color,gloss, and sheen between the touch-up coating and the first andsecond coat.4.3 A qualitative rating scale for the touch-up result isdescribed.5. Sig
11、nificance and Use5.1 During construction of a home, paints are subjected to awide variety of drying conditions, and this may exhibitdifferences between the original coat and the touched-up areain appearance after its full cure. Therefore, it it essential for thepaint to be able to perform under a wi
12、de variety of dryingconditions. A paint that does this is very advantageous to thecontractor.5.2 It is possible for a paint to have excellent color touch-up,but poor sheen touch-up, or vice-versa. The ideal paint willhave both excellent color and sheen touch-up under testingconditions.5.3 Color, glo
13、ss and base choice can have a major impact ontouch-up of the paint.6. Apparatus and Materials6.1 Tinted Test Paint.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.42 on Archit
14、ectural Coatings.Current edition approved July 1, 2009. Published August 2009.2For 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 on
15、the ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Dry Wall Panels, Upson Board, or other acceptedmaterial. Minimum size 30 by 30 cm (1 ft by 1 ft).6.3 Primary Applicator, which could be:6.3.1 Good quality paint rol
16、ler with38 in. nap.6.3.2 Airless spray unit capable of 1000 to 3000 psi andappropriate spray tip.NOTE 1If using an airless spray unit, typically a larger test panel isrequired.6.3.3 Other applicators, as agreed upon.6.4 Secondary Applicator, which could be:6.4.1 Good quality paint roller with 1 cm (
17、38 in.) nap.6.4.2 Good quality polyester/nylon paint brush.6.4.3 A natural or synthetic sponge.6.4.4 Other applicators, as agreed upon.6.5 Controlled Temperature Drying Area/Cabinet, such as:6.5.1 Cold cabinet (refrigerator), maintaining 4 6 2C (406 5F ).6.5.2 Constant temperature room, maintaining
18、25 6 2C (776 5F).6.5.3 May be done in a cabinet maintained at other tem-peratures or humidities, or both, as agreed.6.6 Gloss Meter (optional), to read gloss differences on testpanel.6.7 Spectrophotometer (optional), to read color differenceson test panel.6.8 Bench Scale (optional), to measure weigh
19、t of paintapplied to test.6.9 Ruler (optional), or other measuring device to measurearea of paint application.7. Procedure7.1 Before starting this method, agree upon paints, tintedcolor, applicator types for first coat, second coat and touch-uparea(s), as well as temperature under which each will be
20、applied and dried.7.2 Select a convenient and suitable spreading rate, mutu-ally agreeable to all parties involved in the testing program,and preferably in the range from 8.6 to 11.0 m2/L (350 to450 ft2/gal). SeeAppendix X1 for examples of typical touch-upapplicator and drying conditions.7.2.1 Resul
21、ts may be highly dependent on film thickness;therefore, it is essential that the test paints be weighed onaccurately, particularly for small test areas. The amount ofpaint in grams required for a specific spread rate can bedetermined from the following equation:g 5 Am * D!/Sm! * 1000 (1)where:Am = a
22、rea, square metres,D = density, g/mL or kg/L, andSm = spreading rate, square metres/L.or the following imperial units equation:g 5 A * W!/S! * 3.15 (2)where:A = area, sq. in.,W = weight per gal. (Test Method D 1475), lb./gal, andS = spreading rate, square ft/gal.NOTE 2The gallon unit here and throug
23、hout this test method is the U.S. gallon (3.78 L).NOTE 3To avoid variations in initial gloss, the substrate may requirepriming.7.3 Application of First Coat:7.3.1 The test substrate, applicator for the first coat (appli-cator A) and paint are placed in an area (oven, refrigerator, orconstant tempera
24、ture room) that corresponds with dryingconditions for first coat (drying conditions A), and allowed toequilibrate for at least 4 h.7.3.2 Applicator is broken in or conditioned for use (forexample, Practice D 5068 for paint brushes and PracticeD 5069 for paint rollers).7.3.3 Then, one coat of the tes
25、t paint is applied to the testsubstrate using the applicator A at drying conditions A. Anillustration of the series of three application steps is found inFig. 1. The panel is dried for a minimum of 18 h under dryingconditions A.7.3.3.1 (Optional) If spread rates are being determined,measure the weig
26、ht applied to the test panel using a benchscale, and measure the length and width of the test area.7.4 Application of Second Coat:7.4.1 The application of second coat step may be omitted ifthe critical touch-up being evaluated is directly over a one-coatapplication.FIG. 1 Graphic Representation of F
27、irst and Second Coats and Touch-up AreasD74890927.4.2 The coated test substrate, applicator for the secondcoat (applicator B), and paint are placed in an area (oven,refrigerator, or constant temperature room) that correspondswith drying conditions for second coat (drying conditions B),and allowed to
28、 equilibrate for at least 4 h.NOTE 4Applicator B in the field can typically be the same asapplicator A. Therefore it is acceptable that applicators A and B can be thesame in some cases. See Table X1.1 for an example.7.4.3 Applicator is broken in or conditioned for use (forexample, Practice D 5068 fo
29、r paint brushes and PracticeD 5069 for paint rollers).7.4.4 Then, the second coat of the test paint is applied to aportion of the coated test substrate (roughly 50 %) using theapplicator B at drying conditions B. The panel is dried for aminimum of 18 h under drying conditions B.7.4.4.1 (Optional) If
30、 spread rates are being determined,measure the weight applied and test area as in 7.3.3.1.7.5 Application of the Touch-up Coat:7.5.1 The test panel, applicator for the touch-up coat (ap-plicator C), and paint are placed in an area (oven, refrigerator,or constant temperature room) that corresponds wi
31、th dryingconditions for the touch-up coat (drying conditions C), andallowed to equilibrate for at least 4 h.7.5.2 Applicator is broken in or conditioned for use (forexample, Practice D 5068 for paint brushes and PracticeD 5069 for paint rollers).7.5.3 Then, the touch-up coat of the test paint is app
32、lied toa portion of the test panel, (roughly in the middle of the panel,overlapping both the first and second coat) using the applicatorC at drying conditions C. The panel is dried for a minimum of18 h under drying conditions C.7.5.3.1 (Optional) If spread rates are being determined,measure the weig
33、ht applied and test area as in 7.3.3.1.7.6 After 24 h dry time, remove panel to laboratory andinspect visually for differences in color and gloss.8. Evaluation Procedure8.1 Viewing Conditions for Color DifferenceDeterminationWhen the test and comparison paint panelsare thoroughly dry, place them ver
34、tically against a flat surfaceand view them for a distance of 0.6 to3m(2to10ft)underillumination conditions as described in 9.1.1.8.2 Viewing Conditions for Gloss DifferenceDeterminationWhen the paint panels are thoroughly dry,place them vertically against a flat surface and view them froma distance
35、 of 0.3 to 1.5 m (1 to 5 ft) under illuminationconditions as described in 9.2.1.8.3 Qualitative Evaluation:8.3.1 Refer to Test Method D 344, Practice D 1729, and TestMethod D 6762 for suggestions on visual evaluation of thepanels.8.3.2 If the color or gloss difference between section A andsection B
36、for the test panel are small (not readily apparent), thedifference is considered very good, whereas major differencesare considered poor. See rating chart in 9.3.8.4 Quantitative Evaluation (optional):8.4.1 Refer to Test Method D 523 for measuring instrumen-tal gloss values of the panel sections.8.4
37、.2 Refer to Test Method E 1347 for measuring instru-mental color values and differences of the panel sections.9. Report9.1 Examine the difference in COLOR visually of thetouched-up versus either the one-coated or two-coated section.9.1.1 Note: Evaluate COLOR head-on (perpendicular) tothe panel to el
38、iminate any visual differences in color that maybe present due to differences in gloss. The lighting can be asagreed upon (fluorescent, incandescent, daylight, etc. Forinterior paints, typical lighting used is CIE F2 (or CWF), andfor exterior paints typical lighting used is D65.)9.1.2 Note: Typicall
39、y a hand-held spectrphotometer can beused to back-up visual inspection with numerical differences,but visual determination of color is still the preferred method.9.2 Examine the difference in gloss/gloss visually of thetouched-up versus either the one-coated or two-coated section.9.2.1 Note: View th
40、is gloss at different angles. Usually themost severe angle is almost parallel to the surface for matte orflat paints.9.2.2 Note: Typically a gloss meter will not easily pick upthe visual differences in sheen, but may be used to recordnumerical values if desired.9.3 Qualitative rating system for both
41、 COLOR and GLOSSdifferences (report as two separate ratings for each comparison(touch-up area versus first coat area, touch-up area versussecond coat area, first coat area versus second coat area):Inasmuch as some observations are subjective, they havebeen rated using the following ASTM Standardized
42、 ScoringSystem in order to avoid lengthy descriptions:Score Performance or Effect5 Perfect None4 Very good Very slight3 Good Moderate2 Fair Considerable1 Poor Severe0 No value Complete failure9.3.1 As described in 9.1.2 and 9.2.2, instrumental readingsof color difference (typically L*a*b* DE) and gl
43、oss difference(usually 85 gloss) can also be reported, as agreed upon.9.3.2 Depending on what is agreed upon, the informationreported can include:9.3.2.1 Color and gloss difference between first coat andsecond coat, visual or instrumental, or both.9.3.2.2 Color and gloss difference between first coa
44、t andtouch-up section, visual or instrumental, or both.9.3.2.3 Color and gloss difference between second coat andtouch-up section, visual or instrumental, or both.9.4 Report applicators and drying conditions for each por-tion.9.5 Record any unique conditions (colorants used to tintcolors, tint bases
45、 used, etc.).10. Keywords10.1 color difference; latex paint; sheen difference; touch-upD7489093APPENDIX(Nonmandatory Information)X1. INFORMATIONAL APPENDIXX1.1 Included in Tables X1.1-X1.5 are some examples ofapplicators and drying conditions for a few typical touch-upscenarios.X1.1.1 Other combinat
46、ions of applicators and drying con-ditions can be used.X1.2 Colors typically used may include:X1.2.1 A beige color, typically made of yellow oxide,brown oxide and umber.X1.2.2 A blue-green color, typically made of organic blue,organic green and black.X1.2.3 A blue tinted color.X1.2.4 Note: Straight
47、white will not show color touch-up.TABLE X1.1 Typical Lab Touch-up ScenarioApplicator Drying ConditionsFirst Coat 1 cm (38 in.) nap roller 5 6 1C (40 6 2F) and20 6 5%RHSecond Coat 1 cm (38 in.) nap roller 20 6 1C (72 6 2F) and50 6 5%RHTouch-up Polyester/nylon blendpaint brush20 6 1C (72 6 2F) and50
48、6 5%RHTABLE X1.2 DIY Type Touch-up ScenarioApplicator Drying ConditionsFirst Coat 1 cm (38 in.) nap roller 20 6 1C (72 6 2F) and50 6 5%RHSecond Coat 1 cm (38 in.) nap roller 20 6 1C (72 6 2F) and50 6 5%RHTouch-up Polyester/nylon blendpaint brush20 6 1C (72 6 2F) and50 6 5%RHTABLE X1.3 Winter Constru
49、ction Touch-up Scenario #1Applicator Drying ConditionsFirst Coat17100th, s tip airless spray 5 6 1C (40 6 2F) and20 6 5%RHSecond Coat 1 cm (38 in.) nap roller 20 6 1C (72 6 2F) and50 6 5%RHTouch-up Polyester/nylon blendpaint brush20 6 1C (72 6 2F) and50 6 5%RHTABLE X1.4 Winter Construction Touch-up Scenario #2Applicator Drying ConditionsFirst Coat17100th, s tip airless spray,immediate backroll with1cm(38 in.) nap roller5 6 1C (40 6 2F) and20 6 5%RHSecond Coat 1 cm (38 in.) nap roller 20 6 1C (72 6 2F) and50 6 5%RHTouch-up Natural
