ASTM D5031-23

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Designation: D5031/D5031M − 13 (Reapproved 2018) D5031 − 23
Standard Practice for
Enclosed Carbon-Arc Exposure Tests of Paint and Related
Coatings
This standard is issued under the fixed designation D5031/D5031M;D5031; 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
1.1 This practice covers the selection of test conditions for accelerated exposure testing of coatings and related products in
enclosed carbon arc devices operated according to Practices G151 and G153. This practice also covers the preparation of test
specimens, the test conditions suited for coatings, and the evaluation of test results.Table 1 describes commonly used test
conditions.
1.2 This practice does not cover filtered open-flame carbon-arc exposures of paints and related coatings, which is described in
Practice D822/D822MD822. Another procedure for exposing these products is covered by Practice D3361/D3361M, in which the
specimens are subjected to radiation from an unfiltered open-flame carbon arc that produces shorter wavelengths and higher levels
of short wavelength radiation than filtered open flame or enclosed carbon arcs.
NOTE 1—Practice D3361/D3361M requires use of open-flame carbon-arc apparatus with automatic humidity control.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined.given in parentheses are for information only
and are not considered standard.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D358 Specification for Wood to Be Used as Panels in Weathering Tests of Coatings (Withdrawn 2014)
D523 Test Method for Specular Gloss
This practice is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.27 on Accelerated Testing.
Current edition approved Sept. 1, 2018Dec. 1, 2023. Published September 2018December 2023. Originally approved in 1989. Last previous edition approved in 20132018
as D5031/D5031M – 13. DOI: 10.1520/D5031_D5031M-13R18.– 13 (2018). DOI: 10.1520/D5031-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
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D5031 − 23
A
TABLE 1 Test Cycles Commonly Used for Enclosed Carbon-Arc Exposure Testing of Paints and Related Coatings
Uninsulated Black
B,C,D
Panel Temperature
B,C
Cycle Cycle Description °C °F
E
Typical Uses
Number
Continuous light
102 min light only at 50 ± 10 % RH
63 ± 2.5 145 ± 5
G
18 min light and water spray
Repeated continuously
2 18 h continuous light
using:
102 min light only at
50 ± 10 % RH
63 ± 2.5 145 ± 5
18 min light and water
General coatings
General coatings and historical
24 ± 1.5 75 ± 3
1 G
spray F
convention
6 h dark using:
95 % relative humidity
(no water spray)
Repeated continuously
48 min light at 50 ±
10 % RH
12 min light and water 63 ± 2.5 145 ± 5
spray
Repeated continuously
3 Coatings used
4 h light at 50 ± 10 %
RH
4 h dark with water 63 ± 2.5 145 ± 5
spray
4 Repeated continuously Exterior pigmented stains
12 h light at 50 ± 10 %
RH
63 ± 2.5 145 ± 5
12 h dark water spray
Repeated continuously
8 h light at 50 ± 10 %
5 RH Exterior wood
10 h light and water
spray 63 ± 2.5 145 ± 5
6 Marine enamels
6 h dark with water
spray
Repeated continuously
A
TABLE 1 Test Cycles Commonly Used for Enclosed Carbon-Arc Exposure Testing of Paints and Related Coatings
Cycle Uninsulated Black Chamber
B,C E
Cycle Description Humidity Typical Uses
B,C,D
Number Panel Temperature Temperature
% RH
Continuous light
145 ± 5
63 °C ± 2.5 °C General coatings and historical
1 102 min light only Not controlled
F
(145 °F ± 5 °F) convention
38 °C
G
18 min light and water spray Not controlled Not controlled
(100 °F)
18 h continuous light using:
63 °C ± 2.5 °C
102 min light only Not controlled 50 ± 10
(145 °F ± 5 °F)
38 °C
G
2 General coatings
18 min light and water spray Not controlled Not controlled
(100 °F)
6 h
Not controlled 38 °C ± 2.5 °C
H
95 + 5 - 10
dark
(100 °F ± 5 °F)
(no water spray)
48 min light 63 °C ± 2.5 °C
Not controlled 50 ± 10
(145 °F ± 5 °F) Coatings used in original equipment
38 °C manufacturing
12 min light and water spray Not controlled Not controlled
(100 °F)
4 h light 63 °C ± 2.5 °C
Not controlled 50 ± 10
(145 °F ± 5 °F)
4 Exterior pigmented stains
38 °C
4 h dark with water spray Not controlled Not controlled
(100 °F)
12 h light 63 °C ± 2.5 °C
Not controlled 50 ± 10
(145 °F ± 5 °F)
5 Exterior wood stains and clears
38 °C
12 h dark water spray Not controlled Not controlled
(100 °F)
8 h light at 50 ± 10 % RH 63 °C ± 2.5 °C
Not controlled 50 ± 10
(145 °F ± 5 °F)
38 °C
6 10 h light and water spray Not controlled Not controlled Marine enamels
(100 °F)
38 °C
6 h dark with water spray Not controlled Not controlled
(100 °F)
D5031 − 23
A
The cycles described are not listed in any order indicating importance, and are not necessarily recommended for the applications listed.
B
Unless otherwise specified, operate the device so that the allowable deviations about the set points given in Table 1 are within the specified limits specified in the
corresponding entry. If the actual operating conditions do not agree with the machine settings after the equipment has stabilized, discontinue the test and correct the cause
of the disagreement before continuing.
C
Set points and operational fluctuations are listed as set point ± operational fluctuation in Table 1. They are sometimes listed in separate columns. The set point is the
target condition for the sensor used at the operational control point as programmed by the user. Operational fluctuations are deviations from the indicated set point at the
control point indicated by the readout of the calibrated control sensor during equilibrium operation and do not include measurement uncertainty. At the operational control
point, the operational fluctuation can exceed no more than the listed value at equilibrium. Therefore, when a standard calls for a particular set point, the user programs
that exact number. The operational fluctuations specified with the set point do not imply that the user is allowed to program a set point higher or lower than the exact set
point specified.
D
Unless otherwise indicated, black panel temperatures apply during the light-only portion of the cycle. The equilibrium black panel temperature is obtained without a spray
period. For light intervals less than 30 min, the black panel temperature might not reach equilibrium.
E
Typical uses do not imply that results from exposures of these materials according to the cycle described will correlate to those from actual use conditions.
F
Historical convention has established this as a very commonly used test cycle. This cycle may not adequately simulate the effects of outdoor exposure.
G
Unless otherwise specified, water spray refers to water sprayed on the exposed surfaces of the test specimens.
H
An uninsulated black panel temperature of 24 °C was historically used for the Dark step in Cycle 2. This lower temperature can still be used with the agreement of all
parties.
D609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related Coating
Products
D610 Practice for Evaluating Degree of Rusting on Painted Steel Surfaces
D659 Method for Evaluating Degree of Chalking of Exterior Paints (Withdrawn 1990)
D660 Test Method for Evaluating Degree of Checking of Exterior Paints
D662 Test Method for Evaluating Degree of Erosion of Exterior Paints
D714 Test Method for Evaluating Degree of Blistering of Paints
D772 Test Method for Evaluating Degree of Flaking (Scaling) of Exterior Paints
D822/D822MD822 Practice for Filtered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
D823 Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels
D1005 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
D1186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous
Base (Withdrawn 2006)
D1400 Test Method for Nondestructive Measurement of Dry Film Thickness of Nonconductive Coatings Applied to a
Nonferrous Metal Base (Withdrawn 2006)
D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D1730 Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting
D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
D2616 Test Method for Evaluation of Visual Color Difference With a Gray Scale
D3361/D3361M Practice for Unfiltered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
D4214 Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films
D5870 Practice for Calculating Property Retention Index of Plastics
D7091 Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals
and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G141 Guide for Addressing Variability in Exposure Testing of Nonmetallic Materials
G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G152 Practice for Operating Open Flame Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
G153 Practice for Operating Enclosed Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
G169 Guide for Application of Basic Statistical Methods to Weathering Tests
3. Terminology
3.1 The definitions given in Terminology G113 are applicable to this practice.
4. Significance and Use
4.1 The ability of a paint or coating to resist deterioration of its physical and optical properties caused by exposure to light, heat,
and water can be very significant for many applications. This practice is intended to induce property changes associated with
D5031 − 23
end-use conditions, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to
simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and saltwater
exposure.
4.2 Cautions—Variation in results may be expected when different operating conditions are used. Therefore, no reference to the
use of this practice shall be made unless accompanied by a report prepared according to Section 10 that describes the specific
operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained
according to this practice.
NOTE 2—Additional information on sources of variability and on strategies for addressing variability in the design, execution, and data analysis of
laboratory accelerated exposure tests is found in Guide G141.
4.2.1 The spectral power distribution of light from an enclosed carbon arc is significantly different from that produced in light and
water exposure devices using other carbon-arc configurations or other light sources. The type and rate of degradation and the
performance rankings produced by exposures to enclosed carbon arcs can be much different from those produced by exposures to
other types of laboratory light sources.
4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same type of carbon arc, filters, and exposure
conditions.
4.3 Reproducibility of test results between laboratories has been shown to be good when the stability of materials is evaluated in
4,5
terms of performance ranking compared to other materials or to a control. Therefore, exposure of a similar material of known
performance (a control) at the same time as the test materials is strongly recommended. It is recommended that at least three
replicates of each material be exposed to allow for statistical evaluation of results.
4.4 Test results will depend upon the care that is taken to operate the equipment according to Practice G153. Significant factors
include regulation of line voltage, freedom from salt or other deposits from water, temperature and humidity control, and
conditions of the electrodes.
4.5 All references to exposures in accordance with this practice must include a complete description of the test cycle used.
5. Apparatus
5.1 Use enclosed carbon-arc apparatus that conforms to the requirements defined in Practices G151 and G153.
5.2 Unless otherwise specified, the spectral power distribution of the enclosed carbon arc shall conform to the requirements in
Practice G153 for the enclosed carbon arc.
6. Hazards
6.1 Warning—In addition to other precautions, never look directly at the carbon arc because UV radiation can damage the eye.
Most carbon-arc machines are equipped with door safety switches, but users of old equipment must be certain to turn off the power
to the carbon arc before opening the test-chamber door.
6.2 The burning carbon rods used in these devices become very hot during use. Make sure to allow at least 15 min for the arcs
to cool after the device is turned off before attempting to change the carbon rods.
6.3 Carbon residue and ash are known respiratory irritants. Wear an appropriate high-efficiency dust respirator, gloves, and safety
glasses when handling or changing carbon rods. Make sure to wash any carbon residue from hands or arms prior to eating or
drinking.
Fischer, R., “Results of Round-Robin Studies of Light- and Water-Exposure Standard Practices,” Accelerated and Outdoor Durability Testing of Organic Materials,
ASTM STP 1202, ASTM, 1993.
Ketola, W., and Fischer, R., “Characterization and Use of Reference Materials in Accelerated Durability Tests,” VAMAS Technical Report No. 30, NIST, June 1997.
D5031 − 23
7. Test Specimens
7.1 Apply the coating to flat (plane) panels with the substrate, method of preparation, method of application, coating system, film
thickness, and method of drying consistent with the anticipated end use, or as mutually agreed upon between the producer and user.
7.2 Panel specifications and methods of preparation include but are not limited to Practices D609 or D1730, or Specification D358.
Select panel sizes suitable for use with the exposure apparatus.
7.3 Coat test panels in accordance with Practices D823, then measure the film thickness in accordance with an appropriate
procedure selected from Test Method
...