4. No perceptible change. Cannot be scratched with a finger-nail.REQUIREMENTS:Ratings 3 and 4 are satisfactory.Ratings 1 and 2 are unsatisfactory.For powder coatings, this test is optional in in-house control; it is merely indicative andcannot alone cast doubt upon the quality of the coating.2.15. Resistance to mortarThe test must be performed according to the EN 12206-1 (paragraph 5.9) standard.REQUIREMENTS:The mortar must be easy to remove without leaving any residues. Any mechanicaldamage to the coating caused by grains of sand should be disregarded.Any change in the appearance/colour of metallic coatings must not exceed 1 on thereference scale (see Appendix A4).All other colours must not show any change.2.16. Resistance to boiling waterMethod 1 with boiling water:2 hours in boiling, demineralised water (maximum 10 μS at 20°C). Remove the sampleand allow it to cool down to room temperature. Apply an adhesive tape (see section2.4) to the surface, ensuring that no air is trapped. After one minute, remove the tape atan angle of 45° with a sharp even pull.Method 2 with a pressure cooker :(to be used for powder and electrophoretic coatings only)Add demineralised water (maximum 10 μS at 20°C) to a pressure cooker with aninternal diameter of about 200 mm to a depth of 25 mm and place a test samplemeasuring 50 mm in it.Place the lid in position and heat the pressure cooker until steam escapes from thevalve. The weighted needle valve must be adjusted to produce an internal pressure of100 +/- 10 kPA (1 bar). Continue heating for 1 hour, timing from the moment whensteam first escapes from the valve. Cool the pressure cooker, remove the sample andallow it to cool down to room temperature.Apply an adhesive tape (see section 2.4) to the surface, ensuring that no air is trapped.After one minute, remove the tape at any angle of 45° with a sharp even pull.REQUIREMENTS:No blistering in excess of 2 (S2) according to ISO 4628-2. There must not be anydefects or detachment . Some colour change is acceptable.
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