ASTM D661-93(2011)

Standard Test Method for Evaluating Degree of Cracking of Exterior Paints

SIGNIFICANCE AND USE
Cracking failure of paint films can occur in use. This test method provides a means of evaluating the degree of the failure by comparing the pictorial standards.
SCOPE
1.1 This test method covers the evaluation of the degree of cracking of exterior paints by comparison with photographic standards.

General Information

• Status: Historical
• Publication Date: 31-Oct-2011
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.25 - Evaluation of Weathering Effects

Relations

• Replaces: ASTM D661-93(2005) - Standard Test Method for Evaluating Degree of Cracking of Exterior Paints
• Effective Date: 01-Nov-2011
• Replaced By: ASTM D661-93(2019) - Standard Test Method for Evaluating Degree of Cracking of Exterior Paints
• Effective Date: 01-Oct-2019
• Referred By: ASTM D1014-18 - Standard Practice for Conducting Exterior Exposure Tests of Paints and Coatings on Metal Substrates
• Effective Date: 01-Nov-2011
• Referred By: ASTM D333-01(2021) - Standard Guide for Clear and Pigmented Lacquers
• Effective Date: 01-Nov-2011
• Referred By: ASTM E1605-22 - Standard Terminology Relating to Lead in Buildings
• Effective Date: 01-Nov-2011
• Referred By: ASTM D5722-20 - Standard Practice for Performing Accelerated Outdoor Weathering of Factory-Coated Embossed Hardboard Using Concentrated Natural Sunlight and a Soak-Freeze-Thaw Procedure
• Effective Date: 01-Nov-2011
• Referred By: ASTM D3322-23 - Standard Practice for Testing Primers and Primer Surfacers Over Preformed Metal
• Effective Date: 01-Nov-2011
• Referred By: ASTM D8370-22 - Standard Test Method for Field Measurement of Electrochemical Impedance on Coatings and Linings
• Effective Date: 01-Nov-2011
• Referred By: ASTM D7856-21 - Standard Specification for Color and Appearance Retention of Solid and Variegated Color Plastic Siding Products using CIELab Color Space
• Effective Date: 01-Nov-2011
• Referred By: ASTM D1006/D1006M-21 - Standard Practice for Conducting Exterior Exposure Tests of Hand and Factory Applied Paints on Wood and Wood Composite Materials
• Effective Date: 01-Nov-2011
• Referred By: ASTM D6944-15(2020) - Standard Practice for Determining the Resistance of Cured Coatings to Thermal Cycling
• Effective Date: 01-Nov-2011
• Referred By: ASTM D3451-06(2017) - Standard Guide for Testing Coating Powders and Powder Coatings
• Effective Date: 01-Nov-2011
• Referred By: ASTM D4082-10(2023) - Standard Test Method for Effects of Gamma Radiation on Coatings for Use in Nuclear Power Plants
• Effective Date: 01-Nov-2011
• Referred By: ASTM D6763-16(2022) - Standard Guide for Testing Exterior Wood Stains and Clear Water Repellents
• Effective Date: 01-Nov-2011
• Referred By: ASTM G210-13(2023) - Standard Practice for Operating the Severe Wastewater Analysis Testing Apparatus
• Effective Date: 01-Nov-2011

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D661 − 93 (Reapproved 2011)
Standard Test Method for
Evaluating Degree of Cracking of Exterior Paints
This standard is issued under the fixed designation D661; 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 (´) 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 5.1.1 Irregular Pattern Type—Cracking in which the breaks
in the film are in no definite pattern.
1.1 This test method covers the evaluation of the degree of
5.1.2 Line Type—Cracking in which the breaks in the film
cracking of exterior paints by comparison with photographic
are generally arranged in parallel lines, usually either horizon-
standards.
tally or vertically, over the surface of the film. These breaks
2. Referenced Documents
often follow the line of brush marks.
5.1.3 Sigmoid Type—Cracking in which the breaks in the
2.1 ASTM Standards:
film form a pattern consisting of curves meeting and
D660 Test Method for Evaluating Degree of Checking of
intersecting, usually on a relatively large scale.
Exterior Paints
2.2 Other Standards:
6. Use of Photographic Reference Standards
Pictorial Standards of Coating Defects Handbook
6.1 The photographic reference standards that are part of
3. Terminology
this test method and are provided in the Pictorial Standards of
3.1 Definitions of Terms Specific to This Standard:
Coating Defects Handbook are representative of the degree of
3.1.1 cracking, n—that phenomenon manifested in paint
cracking of exterior paint films. Fig. 1 is for illustration
films by a break extending through to the surface painted.
purposes only and should not be used for evaluation.
3.1.1.1 Discussion—Where this is difficult to determine, the
6.2 The use of the photographic reference standards illus-
break should be called a crack only if the underlying surface is
trated in Fig. 1 requires the following precautions:
visible. The use of a magnification of 10 diameters is recom-
6.2.1 The accompanying photographic reference standards
mended in cases where it is difficult to differentiate between
show line-type cracking only. Irregular and sigmoid-type
cracking and checking (see Test Method D660).
cracking may also be interpreted from these photographs.
4. Significance and Use 6.2.2 Care must be taken not to confuse various types of
failure that may be present on the same surface. This is
4.1 Cracking failure of paint films can occur in use.This test
particularly true in observing cracking and checking. Cracking
methodprovidesameansofevaluatingthedegreeofthefailure
may very often be an advanced stage of checking and is very
by comparing the pictorial standards.
often in evidence along with checking and other failures.
5. Types of Cracking
6.2.3 It must be realized that the degree of failure will vary
over any given area. Therefore, an average portion of the film
5.1 Three types of cracking are recognized:
should be used for comparison. On larger surfaces it is
recommended that ratings be made at several locations and the
This test method is under the jurisdiction of ASTM Committee D01 on Paint
mean and range reported.
and Related Coatings, Materials, andApplications and is the direct responsibility o
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