ASTM D2247 “Method for Testing Water Resistance of Coatings at 100% Relative Humidity” specifies the basic principles and operating procedures for testing water resistance of coatings. Coating samples used for exposure tests are placed in an environment with 100% relative humidity so that condensation will form on the test sample.
ASTM D2247 is the standard method for testing the waterproofness of coatings at 100% relative Humidity

ASTM D2247 specifies the basic principles and operating procedures for coating water resistance testing. Coating samples used for exposure testing are kept at 100% relative humidity so that condensation will form on the test sample.

ASTM D2247-0 “Test Method for Water Resistance of Coatings at 100% Relative Humidity”

1 Scope
(l) This test includes the basic operation steps of the method of testing the water resistance of the coating by condensing the water of the sample at J: 100% relative humidity.

(2) This test only includes measurement methods, control conditions and operation steps under IOO% phase humidity, and does not specifically list sample preparation, specific test conditions and evaluation of results.

(3) The values listed in SI cells are standard values, and the values in parentheses are for reference only.

(4) This standard does not refer to all safety matters in the use of process towels. It is the responsibility of the user to conduct safety tests before use to ensure the feasibility of some basic restrictions.

ASTM D2247-0 “Test Method for Water Resistance of Coatings at 100% Relative Humidity”

2 References
ASTM standard

D609 Test paint, conversion coating and related soil layer products for cold rolled steel plate

D610 Method of test for the degree of rust increase in painted steel

D 714 Test method for the degree of foaming increase of paint

D 823 Test method for uniform coating thickness of paints, conversion coatings and related coating products on samples

D1193 Standard for reagent water

D 1654 Testing of the properties of painted or painted samples in a corrosive environment

D 1730 Tests on the preparation of aluminium and aluminium alloy surfaces in paints

D 1735 Test method for testing the waterproofness of coatings with a water mist meter

D 2616 A test method for evaluating visible color changes using a grayscale test

D 3359 Method of measuring adhesion by adhesive test

D3363 tests the thickness of the film by the pencil method

D4541 Method of measuring coating shedding strength by mobile adhesion tester

D4585 Method for testing the water resistance of coatings by controlled condensation

ASTM D2247-0 “Test Method for Water Resistance of Coatings at 100% Relative Humidity”

3 Test points
The sample is placed in a sealed chamber filled with a mixture of heated saturated air and water vapor, usually maintained at 380C (l00°F). At 100% relative humidity, the small temperature difference between the sample and the surrounding water vapor will cause water droplets to condense in the sample. By changing the time of the test, the external conditions can be adjusted to allow water droplets to infiltrate into the coating. The speed of infiltration is determined by the performance of the coating itself. Attention should be paid to color change, foaming, labor saving, softening, embrittlement and other effects.

4 Importance and use
(1) Moisture can degrade the coating, so knowing the water resistance of the coating is helpful in predicting its service life. The change of coating performance at 100% relative humidity may be caused by the reduction of the coating itself, the contamination of the substrate, the incomplete surface system and other reasons, so this test is also quite useful for the evaluation of the coating or the whole coating system.

(2) Testing at 100% relative humidity is used in accredited standards, quality control, coating and substrate research. The results of this test can determine whether the product is qualified, and the failure rate can be calculated. If there are no signs related to water erosion after a certain period of time, the product can be considered qualified.

(3) The test results obtained according to this test cannot be equivalent to the results after a period of exposure to natural humid environment, unless the coating or coating system is related to the two to some extent.

(4) The test may be a small laboratory room or a room large enough to accommodate a car or truck. Some automobile manufacturers test newly completed vehicles in a room with IOO% relative humidity.

ASTM D2247-0 “Test Method for Water Resistance of Coatings at 100% Relative Humidity”

5 Experimental Equipment
(1) The test chamber is constructed of corrosion-resistant material to accommodate the test samples

(2) The heated water tank is in the laboratory, with a water supply equipment and water surface control equipment.

(3) If the stability control equipment is installed near the sample table temperature sensing device

(4) The thermometer passes through the temperature sensor installed near the sample table

(5) Diagrams and specific values of the equipment used are shown in the appendix

ASTM D2247-0 “Test Method for Water Resistance of Coatings at 100% Relative Humidity”

6 Test samples
(1) This test does not include the preparation of the test sample. Before the test, the underlying composition, table and preparation, sample preparation and sample quantity should be negotiated.

(2) Before each test, it is recommended to use a control sample with known durability of spray paint. This control sample can provide us with a signal when the smile changes in the given equipment, and can also identify small differences in testing in different instruments.

(3) For samples with different coatings, it is recommended to conduct more than 2 repeated tests to offset the variation of different samples and different test conditions.