ASTM D772-86(2000)
(Test Method)Standard Test Method for Evaluating Degree of Flaking (Scaling) of Exterior Paints
Standard Test Method for Evaluating Degree of Flaking (Scaling) of Exterior Paints
SCOPE
1.1 This test method covers the evaluation of the degree of flaking (scaling) of exterior paints by comparison with photographic standards.
1.2 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.
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Standards Content (Sample)
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Designation:D772–86(Reapproved 2000)
Standard Test Method for
Evaluating Degree of Flaking (Scaling) of Exterior Paints
This standard is issued under the fixed designation D 772; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 5. Type of Flaking (Scaling)
1.1 This test method covers the evaluation of the degree of 5.1 Only one type of flaking (scaling) is recognized, as
flaking (scaling) of exterior paints by comparison with photo- defined in Section 3.
graphic standards.
6. Use of Photographic Reference Standards
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 6.1 The photographic reference standards that are part of
this test method and are provided in the Pictorial Standards of
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- Coating Defects Handbook are representative of the degree of
cracking of exterior paint films. Fig. 1 is for illustration
bility of regulatory limitations prior to use.
purposes only and should not be used for evaluation.
2. Referenced Documents 3
6.2 The use of the photographic reference standards illus-
2.1 ASTM Standards: trated in Fig. 1 requires the following precautions:
D 1150 Single and MultiPanel Forms for Recording Results 6.2.1 Care must be taken not to confuse various types of
of Exposure Tests of Paints failure that may be present on the same surface.
2.2 Other Standards: 6.2.2 It must be realized that degree of failure will vary over
Pictorial Standards of Coating Defects Handbook any given area. Therefore, an average portion of the film
should be used for comparison. On larger surfaces it is
3. Terminology
recommended that ratings be made at several locations and the
3.1 Definitions of Terms Specific to This Standard: mean and range reported.
3.2 flaking (scaling), n—that phenomenon manifested in 6.2.3 In technical literature, a distinction is sometimes made
paint films by the actual detachment of pieces of the film itself
between flaking and scaling. In most cases, however, flaking
either from its substrate or from paint previously applied. and scaling refer to the same phenomenon. In some instances,
Flaking(scaling)isgenerallyprecededbycrackingorchecking
the term flaking is used to describe the detachment of pieces of
or blistering, and is the result of loss of adhesion, usually due film less than ⁄4 in. (6.4 mm) in size, and scaling, the
to stress-strain factors coming into play.
detachment of pieces over ⁄4 in. in size. In other instances, the
term flaking is used to describe the detachment of pieces of
4. Significance and Use
film from the immediate undercoat (intercoat failure) and
4.1 Flaking (scaling) failure of paint films can occur in use.
scaling the detachment of pieces from the base (complete
This test method provides a means of evaluating the degree of
failure). It should
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