Active Standard ASTM D870 | Developed by Subcommittee: D01.27
Book of Standards Volume: 06.01
Historical (view previous versions of standard)
Significance and Use
Immersion in water can cause the degradation of coatings. Knowledge on how a coating resists water immersion is helpful in predicting its service life. Failure in a water immersion test may be caused by a number of factors including a deficiency in the coating itself, contamination of the substrate, or inadequate surface preparation. The test is therefore useful for evaluating coatings alone or complete coating systems.
Water immersion tests are used for research and development of coatings and substrate treatments, specification acceptance, and quality control in manufacturing. These tests typically result in a pass or fail determination, but the degree of failure may also be measured. A coating system is considered to pass if there is no evidence of water-related failure after a specified period of time.
Results obtained from water immersion 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.
Corrosion tests of a scribed coating on a ferrous substrate are impractical in water immersion tests as the corrosion products tend to contaminate the water bath. Continuous overflow of the test tank is sometimes required to maintain consistent water quality.
The apparatus for the test is relatively inexpensive and can be as simple as a glass beaker with a stirrer. It is also possible to use very large tanks for testing coated pipe or other large coated products.
1.1 This practice covers the basic principles and operating procedures for testing water resistance of coatings by the partial or complete immersion of coated specimens in distilled or de-mineralized water at ambient or elevated temperatures. Although the apparatus and procedure could be employed in immersion tests using solutions of various materials in water, this practice is limited to tests in water alone.
1.2 This practice is limited to the methods of obtaining, measuring, and controlling the conditions and procedures of water immersion tests. It does not specify specimen preparation, specific test conditions, or evaluation of results.
Note 1—Alternative practices for testing the water resistance of coatings include Practices D 1735
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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
D714 Test Method for Evaluating Degree of Blistering of Paints
D823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
D1193 Specification for Reagent Water
D1654 Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments
D1730 Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting
D1735 Practice for Testing Water Resistance of Coatings Using Water Fog Apparatus
D2247 Practice for Testing Water Resistance of Coatings in 100 % Relative Humidity
D2616 Test Method for Evaluation of Visual Color Difference With a Gray Scale
D3359 Test Methods for Measuring Adhesion by Tape Test
D3363 Test Method for Film Hardness by Pencil Test
D4541 Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers
D4585 Practice for Testing Water Resistance of Coatings Using Controlled Condensation
ICS Number Code 25.220.20 (Surface treatment)