ASTM D7489-09
(Practice)Standard Practice for Evaluating Touch-Up Properties of Architectural Coatings under Various Environmental Conditions
Standard Practice for Evaluating Touch-Up Properties of Architectural Coatings under Various Environmental Conditions
SIGNIFICANCE AND USE
During construction of a home, paints are subjected to a wide variety of drying conditions, and this may exhibit differences between the original coat and the touched-up area in appearance after its full cure. Therefore, it it essential for the paint to be able to perform under a wide variety of drying conditions. A paint that does this is very advantageous to the contractor.
It is possible for a paint to have excellent color touch-up, but poor sheen touch-up, or vice-versa. The ideal paint will have both excellent color and sheen touch-up under testing conditions.
Color, gloss and base choice can have a major impact on touch-up of the paint.
SCOPE
1.1 This practice determines the ability of a paint to be recoated or “touched up” in small areas. Variations in color, gloss, and sheen that result in a different appearance from the original paint can be evaluated visually.
1.2 This practice describes evaluation of touch-up characteristics in a laboratory-scale controlled environment as opposed to a full-scale field environment.
1.3 Evaluation of touch-up properties under constant drying conditions is described. Environmental conditions can be adjusted to incorporate high or low temperature drying , or both. The changes in application temperature can lead to larger differences in touch-up than applying both coats under the same environmental conditions.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: D7489 − 09
StandardPractice for
Evaluating Touch-Up Properties of Architectural Coatings
under Various Environmental Conditions
This standard is issued under the fixed designation D7489; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Evaluation of Architectural Coatings
D6762 Test Method for Determining the Hiding Power of
1.1 This practice determines the ability of a paint to be
Paint by Visual Evaluation of Spray Applied Coatings
recoated or “touched up” in small areas. Variations in color,
E1347 Test Method for Color and Color-Difference Mea-
gloss, and sheen that result in a different appearance from the
surement by Tristimulus Colorimetry
original paint can be evaluated visually.
1.2 This practice describes evaluation of touch-up charac-
3. Terminology
teristics in a laboratory-scale controlled environment as op-
3.1 Definitions:
posed to a full-scale field environment.
3.1.1 touch-up, n—to repair visual differences in a painted
1.3 Evaluation of touch-up properties under constant drying
surface by recoating small areas with the same paint that was
conditions is described. Environmental conditions can be
used for the original coat.
adjusted to incorporate high or low temperature drying , or
3.1.1.1 Discussion—This includes color and sheen differ-
both.The changes in application temperature can lead to larger
ences in the dry film.
differences in touch-up than applying both coats under the
same environmental conditions. 4. Summary of Practice
1.4 This standard does not purport to address all of the 4.1 Paints, application tools, and drying conditions are
safety concerns, if any, associated with its use. It is the
selected before starting this practice. Relevant color(s) for
responsibility of the user of this standard to establish appro- testing and any specific primers should also be selected at this
priate safety and health practices and determine the applica-
time.
bility of regulatory limitations prior to use.
4.2 Multiple coats of the test paint are applied to a specified
substrate in a prescribed manner to simulate touch-up condi-
2. Referenced Documents
tions. The results are visually evaluated for variations in color,
2.1 ASTM Standards:
gloss, and sheen between the touch-up coating and the first and
D344 Test Method for Relative Hiding Power of Paints by
second coat.
the Visual Evaluation of Brushouts
4.3 A qualitative rating scale for the touch-up result is
D523 Test Method for Specular Gloss
described.
D1475 Test Method For Density of Liquid Coatings, Inks,
and Related Products
5. Significance and Use
D1729 Practice for Visual Appraisal of Colors and Color
5.1 During construction of a home, paints are subjected to a
Differences of Diffusely-Illuminated Opaque Materials
wide variety of drying conditions, and this may exhibit
D5068 Practice for Preparation of Paint Brushes for Evalu-
differences between the original coat and the touched-up area
ation
in appearance after its full cure.Therefore, it it essential for the
D5069 Practice for Preparation of Paint-Roller Covers for
paint to be able to perform under a wide variety of drying
conditions. A paint that does this is very advantageous to the
contractor.
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications and is the direct responsibility of
5.2 Itispossibleforapainttohaveexcellentcolortouch-up,
Subcommittee D01.42 on Architectural Coatings.
but poor sheen touch-up, or vice-versa. The ideal paint will
Current edition approved July 1, 2009. Published August 2009. DOI: 10.1520/
have both excellent color and sheen touch-up under testing
D7489-09.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or conditions.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.3 Color,glossandbasechoicecanhaveamajorimpacton
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. touch-up of the paint.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7489 − 09
6. Apparatus and Materials 7.2 Select a convenient and suitable spreading rate, mutu-
ally agreeable to all parties involved in the testing program,
6.1 Tinted Test Paint.
and preferably in the range from 8.6 to 11.0 m /L (350 to
6.2 Dry Wall Panels, Upson Board , or other accepted 2
450 ft /gal). See Appendix X1 for examples of typical
material. Minimum size 30 by 30 cm (1 ft by 1 ft).
touch-up applicator and drying conditions.
6.3 Primary Applicator, which could be: 7.2.1 Results may be highly dependent on film thickness;
6.3.1 Good quality paint roller with ⁄8 in. nap. therefore, it is essential that the test paints be weighed on
6.3.2 Airless spray unit capable of 1000 to 3000 psi and accurately, particularly for small test areas. The amount of
appropriate spray tip. paint in grams required for a specific spread rate can be
determined from the following equation:
NOTE 1—If using an airless spray unit, typically a larger test panel is
required. g 5 Am*D /Sm *1000 (1)
~~ ! !
6.3.3 Other applicators, as agreed upon.
where:
6.4 Secondary Applicator, which could be:
Am = area, square metres,
6.4.1 Good quality paint roller with 1 cm ( ⁄8 in.) nap. D = density, g/mL or kg/L, and
6.4.2 Good quality polyester/nylon paint brush. Sm = spreading rate, square metres/L.
6.4.3 A natural or synthetic sponge.
or the following imperial units equation:
6.4.4 Other applicators, as agreed upon.
g 5 A*W /S *3.15 (2)
~~ ! !
6.5 Controlled Temperature Drying Area/Cabinet, such as:
where:
6.5.1 Cold cabinet (refrigerator), maintaining 4 6 2°C (40
A = area, sq. in.,
6 5°F ).
W = weight per gal. (Test Method D1475), lb./gal, and
6.5.2 Constanttemperatureroom,maintaining25 62°C(77
S = spreading rate, square ft/gal.
6 5°F).
NOTE 2—The gallon unit here and throughout this test method is the U.
6.5.3 May be done in a cabinet maintained at other tem-
S. gallon (3.78 L).
peratures or humidities, or both, as agreed.
NOTE 3—To avoid variations in initial gloss, the substrate may require
6.6 Gloss Meter (optional), to read gloss differences on test priming.
panel.
7.3 Application of First Coat:
7.3.1 The test substrate, applicator for the first coat (appli-
6.7 Spectrophotometer (optional) , to read color differences
cator A) and paint are placed in an area (oven, refrigerator, or
on test panel.
constant temperature room) that corresponds with drying
6.8 Bench Scale (optional), to measure weight of paint
conditions for first coat (drying conditions A), and allowed to
applied to test.
equilibrate for at least 4 h.
6.9 Ruler (optional), or other measuring device to measure
7.3.2 Applicator is broken in or conditioned for use (for
area of paint application.
example, Practice D5068 for paint brushes and Practice D5069
for paint rollers).
7. Procedure
7.3.3 Then, one coat of the test paint is applied to the test
7.1 Before starting this method, agree upon paints, tinted substrate using the applicator A at drying conditions A. An
color, applicator types for first coat, second coat and touch-up illustration of the series of three application steps is found in
area(s), as well as temperature under which each will be Fig. 1. The panel is dried for a minimum of 18 h under drying
applied and dried. conditions A.
FIG. 1 Graphic Representation of First and Second Coats and Touch-up Areas
D7489 − 09
7.3.3.1 (Optional) — If spread rates are being determined, 8.3.1 Refer to Test Method D344, Practice D1729, and Test
measure the weight applied to the test panel using a bench Method D6762 for suggestions on visual evaluation of the
scale, and measure the length and width of the test area. panels.
8.3.2 If the color or gloss difference between section A and
7.4 Application of Second Coat :
section B for the test panel are small (not readily apparent), the
7.4.1 The application of second coat step may be omitted if
difference is considered very good, whereas major differences
the critical touch-up being evaluated is directly over a one-coat
are considered poor. See rating chart in 9.3.
application.
8.4 Quantitative Evaluation (optional) :
7.4.2 The coated test substrate, applicator for the second
8.4.1 Refer to Test Met
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