Significance and Use
The ability to quickly and accurately evaluate and predict long-term weathering performance of factory-applied coatings is of paramount importance in making sound business and technical decisions.
It is important to include control specimens of known field performance to determine the efficacy of this practice for specific substrate(s) and coating system(s). These control specimens may include materials known to possess acceptable and unacceptable field performance for the defect(s) under consideration.
Results derived from this practice are best used to compare the relative performance of materials tested at the same time in the same device.
The inclusion of control specimens and their resulting data will assist in dealing with test variability caused by seasonal or annual variations in important climatic factors.
Extensive research was performed during the development of this standard practice. This research showed that this practice is not useful for determination of quantitative acceleration factors. However, this test is very useful as a comparative test.
A minimum of two replicates for both control specimens and test specimens is recommended to allow statistical evaluation of results. Refer to Practice G 169 for additional guidance on establishing the number of replicates.
1.1 This practice covers techniques to accelerate weathering effects of factory-coated embossed hardboard using Cycle 1 of Practice G 90 (concentrated natural sunlight with periodic surface water spray) plus a soak-freeze thaw cycle (see Section 5 of this practice).
1.2 Testing by use of the methods described in this practice may be employed in the qualitative assessment of weathering effects. The relative durability of coated hardboards may be best determined by comparison of their test results with those of control specimens derived from real time exposure test experience.
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.
D660 Test Method for Evaluating Degree of Checking of Exterior Paints
D661 Test Method for Evaluating Degree of Cracking of Exterior Paints
D662 Test Method for Evaluating Degree of Erosion of Exterior Paints
D772 Test Method for Evaluating Degree of Flaking (Scaling) of Exterior Paints
D4214 Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films
G90 Practice for Performing Accelerated Outdoor Weathering of Nonmetallic Materials Using Concentrated Natural Sunlight
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G169 Guide for Application of Basic Statistical Methods to Weathering Tests
accelerated weathering; factory coatings (hardboard); film integrity; hardboard (composition board siding); Accelerated aging/testing--paints/related coatings; Film--paints/related coatings/materials; Factory-applied coatings; Film integrity; Hardboard; Outdoor weathering; Soak-freeze-thaw procedure; Sunlight/monochromatic light exposure
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Citing ASTM Standards
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