ASTM D5402-15 pdf free download.Standard Practice for Assessing the Solvent Resistance of Organic Coatings Using Solvent Rubs.
1.1 This practice describes a solvent rub technique for assessing the solvent resistance of an organic coating that
chemically changes during the curing process. This technique can be used in the laboratory, in the field, or in the fabricating shop. Test Method D4752 is the preferred method for ethyl silicate zinc-rich primers.
1.2 This practice does not specify the solvent, number of double rubs, or expected test results.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
3. Terminology
3. 1 Definitions of Terms Specific to This Standard:
3. 1.1 double rub, n—the act of rubbing a cloth in OflC complete forward and back motion ovcr a coated surface.
4. Significance and Use
4.1 Coatings that chemically change during the curing process. such as epoxies, vinyl esters, polyesters, alkyds and urethanes, become more resistant to solvents as they cure. These coatings should reach specific levels of solvent resistance prior to being topcoated and prior to placing in service; the levels of solvent resistance necessary vary with the type of coating and the intended service. Rubbing with a cloth saturated with the appropriate solvent is one way to determine when a specific level of solvent resistance is reached. However, the level of solvent resistance by itself does not indicate full cure and some coatings become solvent resistant before they become sufficiently cured for service.
4.2 The time required to reach a specific level of solvent resistance can be influenced by temperature, film thickness, air movement and, for water-borne or water-reactive coatings, humidity.
4.3 The test solvent’s effect upon the coating varies with coating type and solvent used. The coating manufacturer may specify the solvent, the number of double rubs, and the specific test results needed.
5. Materials and Equipment
5. 1 Solvent:
5.1.1 Methyl Ethyl Ketone (MEK), conforming to Specification D740, or
5. 1 .2 Mineral Spirits, conforming to Specification D235, or
5.1.3 Xylene, conforming to Specification D843, or
5.1.4 Other Solvents, as specified by the coating manufacturer or user.
6. Procedure
Method A (Standard Method)
6.1 If the testing is being performed in a laboratory setting, before actually testing the specimens, perform a sufficient number of double rubs with the index linger covered with a cotton cloth on a laboratory balance such that 1000 to 2000 g of force is constantly being applied. This is the amount of pressure the operator will apply when testing the specimens, and will be considered as being moderate pressure.
6.2 Select areas on the coated surface at least 100-mm (4-in.) long on which to run the tests. Clean the surface with tap water to remove any loose material and allow to dry.
6.3 Measure the dry-film thickness of the coating in the selected areas in accordance with Test Methods D4 138 or Practice D7O91. Mark a 100- by 25-mm (4- by 1-in.) rectangular test area on the undamaged. cleaned surface using a pencil or other suitable solvent resistant marker.ASTM D5402 pdf download.