GB/T 30648.2:2015 Paints and varnishes — Determination of resistance to liquids — Part 2: Water immersion method
1 Scope
This part of GB/T 30648 specifies a method for determining the resistance of an individual-layer or multi-layer system of coating materials to the effects of water by partial or full immersion.
This method enables the determination of the effects of water on the coating and, if necessary, the assessment of the damage to the substrate.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 3186 Paints, varnishes and raw materials for paints and varnishes - Sampling (GB/T 3186-2006, ISO 15528:2000, IDT)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696:1987, MOD)
GB/T 7790 Paints and varnishes - Determination of resistance to cathodic disbonding of coatings exposed to sea water (GB/T 7790-2008, ISO 15711:2003, MOD)
GB/T 9271 Paints and varnishes - Standard panels for testing (GB/T 9271-2008,ISO 1514:2004, MOD)
GB/T 13452.2 Paints and varnishes - Determination of film thickness (GB/T 13452.2-2008, ISO 2808:2007, IDT)
GB/T 20777 Paints and varnishes - Examination and preparation of samples for testing (GB/T 20777-2006, ISO 1513:1992, IDT)
ISO 4628-2 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 2: Assessment of degree of blistering
ISO 17872 Paints and varnishes - Guidelines for the introduction of scribe marks through coatings on metallic panels for corrosion testing
3 Principle
A coated test panel is immersed in water and the effects of immersion are evaluated by criteria agreed in advance.
4 Apparatus
All parts of the apparatus in contact with water shall be made from inert materials.
Ordinary laboratory equipment and the following apparatus:
— Tank: of suitable size, fitted with a cover, a heater and thermostatic control. A convenient size of tank is 700 mm × 400 mm × 400 mm;
— System for circulation and aeration of water: or a means for stirring, used in conjunction with a source of dry, oil-free, pressurized air. If a pump is used, it shall be of a suitable capacity to agitate the whole contents of the tank;
— Support for the test panels, made from material that is electrically non-conducting, and arranged so that the panels are maintained at an angle of 15° to 20° to the vertical, with the test surface uppermost, and with their plane parallel to the direction of flow of water in the tank. The panels shall be at least 30 mm apart, situated at least 30 mm from the bottom of the tank and at least 30 mm from the walls of the tank. Their positions shall be changed periodically, either mechanically or by hand.
Foreword II
1 Scope
2 Normative references
3 Principle
4 Apparatus
5 Sampling
6 Test panels
7 Procedure
8 Evaluation
9 Precision
10 Test report
