ASTM D2247-15(2020)
(Practice)Standard Practice for Testing Water Resistance of Coatings in 100 % Relative Humidity
Standard Practice for Testing Water Resistance of Coatings in 100 % Relative Humidity
SIGNIFICANCE AND USE
4.1 Water can cause the degradation of coatings, so knowledge of how a coating resists water is helpful for assessing how it will perform in actual service. Failure in tests at 100 % relative humidity may be caused by a number of factors including a deficiency in the coating itself, contamination of the substrate, or inadequate surface preparation. This practice is therefore useful for evaluating coatings alone or complete coating systems.
4.2 Tests at 100 % relative humidity are used for specification acceptance, quality control, and research and development for coatings and substrate treatments. Some tests are used for a pass or fail determination at an arbitrary time. A coating system is considered to pass if there is no evidence of water-related failure after a period of time. Other tests are used to monitor degree of failure as a function of exposure time.
4.2.1 Arbitrary pass/fail levels and the test durations required are typically set in other material specific test methods. Users of this practice alone may use the known performance of the controls to set test end points. Another option is to continue the test until all specimens have failed, and use the time to reach failure as a way to differentiate performance.
4.3 Results obtained from the use of 100 % humidity tests in accordance with this practice should not be represented as being equivalent to a period of exposure to water in the natural environment, until the degree of quantitative correlation has been established for the coating or coating system.
4.4 The test chamber can be a small laboratory cabinet or a room large enough to hold an automobile or a truck. Some automobile manufacturers test completed vehicles in rooms maintained at 100 % relative humidity. Corrosion tests can be conducted, as the condensate dripping off the test articles in not recirculated.
SCOPE
1.1 This practice covers the basic principles and operating procedures for testing water resistance of coatings by exposing coated specimens in an atmosphere maintained at 100 % relative humidity so that condensation forms on all surfaces of test specimens.
1.2 This practice uses the technique of creating a slight temperature differential within the exposure area to form condensation on the coated specimens. As the warmer saturated air passes the cooler specimens, water is deposited onto the specimens in the form of condensation.
1.3 This practice places the entire specimen in the exposure area allowing condensation to form on all surfaces. This makes this practice suitable for flat panels as well as large or 3D objects. This practice differs from other methods where condensation is only formed on the front coating surface, while the back surface is outside the exposure area. Other tests may also deposit water droplets on the surface but where the source is not from condensation (for example, water spray).
Note 1: Alternative practices for testing the water resistance of coatings include Practices D870, D1735, and D4585.
1.4 This practice is limited to the methods of obtaining, measuring, and controlling the conditions and procedures of tests conducted in 100 % relative humidity. It does not specify specimen preparation, or evaluation of results.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 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.
1.7 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 Org...
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Standards Content (Sample)
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.
Designation: D2247 − 15 (Reapproved 2020)
Standard Practice for
Testing Water Resistance of Coatings in 100 % Relative
Humidity
This standard is issued under the fixed designation D2247; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice covers the basic principles and operating
ization established in the Decision on Principles for the
procedures for testing water resistance of coatings by exposing
Development of International Standards, Guides and Recom-
coated specimens in an atmosphere maintained at 100 %
mendations issued by the World Trade Organization Technical
relative humidity so that condensation forms on all surfaces of
Barriers to Trade (TBT) Committee.
test specimens.
1.2 This practice uses the technique of creating a slight
2. Referenced Documents
temperature differential within the exposure area to form
2.1 ASTM Standards:
condensation on the coated specimens. As the warmer satu-
D609 Practice for Preparation of Cold-Rolled Steel Panels
rated air passes the cooler specimens, water is deposited onto
for Testing Paint, Varnish, Conversion Coatings, and
the specimens in the form of condensation.
Related Coating Products
1.3 This practice places the entire specimen in the exposure
D610 Practice for Evaluating Degree of Rusting on Painted
area allowing condensation to form on all surfaces.This makes
Steel Surfaces
this practice suitable for flat panels as well as large or 3D
D714 Test Method for Evaluating Degree of Blistering of
objects. This practice differs from other methods where con-
Paints
densationisonlyformedonthefrontcoatingsurface,whilethe
D823 Practices for Producing Films of Uniform Thickness
back surface is outside the exposure area. Other tests may also
of Paint, Coatings and Related Products on Test Panels
deposit water droplets on the surface but where the source is
D870 Practice for Testing Water Resistance of Coatings
not from condensation (for example, water spray).
Using Water Immersion
NOTE 1—Alternative practices for testing the water resistance of
D1193 Specification for Reagent Water
coatings include Practices D870, D1735, and D4585.
D1654 Test Method for Evaluation of Painted or Coated
1.4 This practice is limited to the methods of obtaining,
Specimens Subjected to Corrosive Environments
measuring, and controlling the conditions and procedures of
D1730 Practices for Preparation of Aluminum and
tests conducted in 100 % relative humidity. It does not specify
Aluminum-Alloy Surfaces for Painting
specimen preparation, or evaluation of results.
D1735 Practice for Testing Water Resistance of Coatings
1.5 The values stated in SI units are to be regarded as the Using Water Fog Apparatus
standard. The values given in parentheses are for information D2616 Test Method for Evaluation of Visual Color Differ-
only. ence With a Gray Scale
D3359 Test Methods for Rating Adhesion by Tape Test
1.6 This standard does not purport to address all of the
D3363 Test Method for Film Hardness by Pencil Test
safety concerns, if any, associated with its use. It is the
(Withdrawn 2020)
responsibility of the user of this standard to establish appro-
D4541 Test Method for Pull-Off Strength of Coatings Using
priate safety, health, and environmental practices and deter-
Portable Adhesion Testers
mine the applicability of regulatory limitations prior to use.
1 2
This practice is under the jurisdiction of ASTM Committee D01 on Paint and For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Related Coatings, Materials, and Applications and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D01.27 on Accelerated Testing. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2020. Published June 2020. Originally the ASTM website.
approved in 1966. Last previous edition approved in 2015 as D2247 – 15. DOI: The last approved version of this historical standard is referenced on
10.1520/D2247-15R20. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2247 − 15 (2020)
D4585 Practice for Testing Water Resistance of Coatings 5.2.2 Water Vapor (Steam) Generator, located outside the
Using Controlled Condensation test chamber, a water supply, and a means of introducing the
vapor to the test chamber.
3. Summary of Practice
5.3 Thermostatic Control, for the water heater with the
3.1 Coated specimens are placed in an enclosed chamber
sensor located adjacent to the specimen holders, or a means of
containing a heated, saturated mixture of air and water vapor.
controlling volume of steam.
The temperature of the chamber is usually maintained at 38°C
5.4 Thermometer, with sensor located adjacent to the speci-
(100°F). At 100 % relative humidity (RH), a very small
men holders.
temperaturedifferencebetweenthespecimenandthesurround-
5.5 Diagrams and details of the apparatus are shown in
ing vapor causes the formation of condensation on the speci-
Appendix X1.
mens. The exposure condition is varied by selecting the
duration of the test. Water permeates the coating at rates that
6. Test Specimens
are dependent upon the characteristics of the coating. Any
6.1 This practice does not cover the preparation of test
effects such as color change, blistering, loss of adhesion,
specimens. The substrate composition and surface preparation,
softening, or embrittlement are observed and reported.
specimen preparation, and the number of specimens should be
4. Significance and Use
agreed upon prior to testing.
4.1 Water can cause the degradation of coatings, so knowl-
NOTE 2—Applicable methods for the preparation of test panels and
edgeofhowacoatingresistswaterishelpfulforassessinghow
substrates are given in Practices D609 and D1730. Practices D823 cover
application techniques for the production of uniform films.
it will perform in actual service. Failure in tests at 100 %
relative humidity may be caused by a number of factors
6.2 It is recommended that a control specimen of a coating
including a deficiency in the coating itself, contamination of
withknowndurabilityandsimilarfailuretypebeincludedwith
the substrate, or inadequate surface preparation. This practice
each test. Such control specimens can provide warning of
is therefore useful for evaluating coatings alone or complete
changes in test severity in a given apparatus, and can indicate
coating systems.
variations in test severity between different apparatuses. Best
practice is to use two different control specimens, one with
4.2 Tests at 100 % relative humidity are used for specifica-
known relatively poor performance, and one with known
tion acceptance, quality control, and research and development
relatively good performance. The use of control specimens
for coatings and substrate treatments. Some tests are used for a
with known performance can also be used to determine the
passorfaildeterminationatanarbitrarytime.Acoatingsystem
duration of the test that is required to produce meaningful
is considered to pass if there is no evidence of water-related
results.
failure after a period of time. Other tests are used to monitor
degree of failure as a function of exposure time.
6.3 It is recommended that at least two replicate specimens
4.2.1 Arbitrary pass/fail levels and the test durations re-
of each different coating be used, so as to compensate for
quired are typically set in other material specific test methods.
variations between specimens and potential variations in test
Users of this practice alone may use the known performance of
conditionswiththedevice.Ifmorethanonereplicatespecimen
the controls to set test end points.Another option is to continue
is exposed, place the replicates in different locations in the
the test until all specimens have failed, and use the time to
exposure area.
reach failure as a way to differentiate performance.
7. Procedure
4.3 Resultsobtainedfromtheuseof100 %humiditytestsin
7.1 Generate the saturated water vapor with reagent water
accordance with this practice should not be represented as
conforming to at least the requirements of Type IV of Speci-
being equivalent to a period of exposure to water in the natural
fication D1193.
environment, until the degree of quantitative correlation has
been established for the coating or coating system.
7.2 Unlessotherwisespecified,adjustthetemperatureofthe
saturated air and water vapor mixture so that the air tempera-
4.4 The test chamber can be a small laboratory cabinet or a
ture next to the test specimens is 38°C. During equilibrium
room large enough to hold an automobile or a truck. Some
operation,thetemperatureofthesensorusedtomeasuretheair
automobile manufacturers test completed vehicles in rooms
next to the specimens can vary by a maximum of 62°C from
maintained at 100 % relative humidity. Corrosion tests can be
the desired temperature. If a temperature set point different
conducted,asthecondensatedrippingoffthetestarticlesinnot
from 38°C is used, it must be included in the Test Report.
recirculated.
7.2.1 The temperature of the water vapor will typically be
5. Apparatus the same or higher than the air temperature next to the
specimens. This is a requirement in order for this procedure to
5.1 Test Chamber, constructed of corrosion-resistant mate-
work correctly. The temperature of the water in the vapor
rials with supports for the test specimens.
generation is not set by this practice but water vapor tempera-
5.2 Source of Heated Water Vapor can be created by one of
tures that are greater than 38°C tend to make condensation
the following methods:
more uniform over the test specimens.
5.2.1 Heated Water Tank, within the test chamber, a water
NOTE3—Duetoheatlosstothespecimensandthewallsofthechamber
supply, and a water level control. where a heated water tank is used, the temperature of the water in the tank
D2247
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