Betekenis en doel
4.1 Onderdompeling in water kan degradatie van de coating veroorzaken. Understanding how a coating resists water immersion can help predict its service life. A water immersion test failure can be caused by a variety of factors, including defects in the coating itself, contamination of the substrate, or inadequate surface treatment. Daarom, the test can be used to evaluate individual coatings or complete coating systems.

4.2 Water immersion testing is used for coating and substrate treatment research and development, specification acceptance, and quality control in manufacturing. These tests typically lead to a determination of pass or failure, but can also measure the extent of failure. If there is no evidence of water-related failure after a specified time period, the coating system is considered to have passed.

4.3 Until the quantitative relevance of the coating or coating system is determined, the results obtained from water immersion tests performed in accordance with this protocol should not be expressed as equivalent to a period of exposure to water in the natural environment.

ASTM D 870-2020 Bepaling van de waterbestendigheid van coatings door middel van onderdompelingsmethode

4.4 In water immersion testing, it is impractical to perform corrosion tests on scribe coatings on ferrous metal substrates because corrosion products tend to contaminate the water bath. It is sometimes necessary to test the continuous overflow of the tank to maintain consistent water quality.

4.5 The equipment used for testing is relatively inexpensive and can be as simple as a glass beaker with a stirrer. Very large tanks can also be used to test coated tubes or other large coated products.

Reikwijdte van
1.1 The practice covers the fundamentals and operating procedures for testing the water resistance of a coating by immersing part or all of the coated specimen in distilled or softened water at room temperature or high temperature. Although immersion tests can be performed using solutions of various materials in water, the practice is limited to testing only in water.

1.2 This practice is limited to methods of obtaining, measuring and controlling the conditions and procedures of the immersion test. It does not specify sample preparation, specific test conditions, or evaluation of results.

Opmerking 1: Alternative practices for testing paint for water resistance include D1735, D2247 and D4585.

ASTM D 870-2020 Bepaling van de waterbestendigheid van coatings door middel van onderdompelingsmethode

1.3 Waarden uitgedrukt in SI-eenheden worden als normen beschouwd. De waarden tussen haakjes zijn alleen ter referentie.

1.4 Deze norm is niet bedoeld om alle veiligheidsproblemen aan te pakken, indien aanwezig, die verband houden met het gebruik ervan. Het is de verantwoordelijkheid van de gebruiker van deze norm om de juiste veiligheid te garanderen, gezondheids- en milieupraktijken en om vóór gebruik de toepasbaarheid van wettelijke beperkingen vast te stellen.

1.5 Deze internationale norm is ontwikkeld in overeenstemming met de internationaal erkende standaardisatieprincipes die zijn vastgelegd in het Besluit over de beginselen voor de ontwikkeling van internationale normen, Richtlijnen en aanbevelingen uitgegeven door het Comité voor technische handelsbelemmeringen van de Wereldhandelsorganisatie.