ASTM D6762-02a(2009)e1

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
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Designation:D6762–02a Designation:D6762–02a(Reapproved2009)
Standard Test Method for
Determining the Hiding Power of Paint by Visual Evaluation
of Spray Applied Coatings
This standard is issued under the fixed designation D 6762; 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.
´ NOTE—Units statement in 1.3 was added editorially in July 2009.
1. Scope
1.1 This test method provides for the quantitative visual determination of the film thickness required to achieve full hiding.This
film thickness is considered to be the hiding power of a test paint.
1.2 This method applies only to spray applied coatings but its concepts are valid for other methods of application as well.
1.3
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
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
2.1 ASTM Standards:
D16 Terminology for Paint, Related Coatings, Materials, and Applications
D 609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related
Coating Products
D 1005 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
D 1186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous
Base
D 1400 Test Method for Nondestructive Measurement of Dry Film Thickness of Nonconductive Coatings Applied to a
Nonferrous Metal Base
D 1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D 1730 Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting
D 2805 Test Method for Hiding Power of Paints by Reflectometry
E 691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology D 16 and the Paint/Coatings
Dictionary.
4. Summary of Test Method
4.1 The test paint is applied by means of spray application in a wedge-shaped film over a black and white, black and gray or
red and gray pattern so that a thickness variation is obtained, which provides excess hiding at one end of the pattern and partial
hiding at the other end of the pattern.
4.2 The dry film is examined under standard illumination to select the point where the pattern just becomes obscured. The
This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.26 on Optical Properties.
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Current edition approved Dec. 10, 2002. Published February 2003. Originally approved in 2002. Last previous edition approved in 2002 as D6762-02 .
Current edition approved July 1, 2009. Published July 1, 2009. Originally approved in 2002. Last previous edition approved in 2002 as D 6762 - 02a.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 06.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
Annual Book of ASTM Standards, Vol 02.05.
Published by the Federation of Societies for Coatings Technology, 492 Norristown Rd., Blue Bell, PA 19422.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D6762–02a (2009)
thickness of the film at this point is designated the hiding power of the paint.
5. Significance and Use
5.1 This test method determines hiding power of a test paint by visual evaluation of a spray applied coating.
NOTE 1—Test Method D 2805 describes an instrumental method for determining hiding power. The paint film is applied at a uniform thickness (for
example with a doctor blade), the film thickness is measured rigorously, and the opacity is determined photometrically. Hiding power is thereby
determined with a high degree of precision.
5.2 Test Method D 6762 is less precise than Test Method D 2805, but is commonly used since it is more closely related to the
application characteristics of the paint and is simpler in concept and evaluation.
6. Apparatus
6.1 Test Surface, a smooth-surfaced paper chart, approximately 2 by 11 in., with a test pattern having adjacent black and white,
black and gray or red and gray areas and coated with a suitable varnish or lacquer so as to render the surface impervious to paint
liquids.
NOTE 2—The red, gray, white and black areas should fall in the following colorimetric range:
A A
CIE-Y % C h
Red 4–7 10–18 26–38
Gray 28–34
White 80–83
Black 1 max
A 10 2
Valid for Illuminant D65 or C , with 0°/45° geometry.
6.2 Illumination, a light source providing diffuse light of reasonable intensity, preferably northern sky light or an approximation
of the same (see Practice D 1729).
6.3 Backer Panel, 4 by 12 in. steel or aluminum panel. A larger panel may be used if desired.
6.4 Film Thickness Measuring Device , a film thickness measuring device in accordance with Test Methods D 1005, D 1186,
and D 1400.
6.5 Spray Equipment, either a hand spray gun or an automatic spray machine.
6.6 Oven, capable of maintaining the bake schedule for the product being evaluated.
6.7 Tape, masking or adhesive.
7. Preparation of Wedge-shaped Paint Film (Hand Spray)
7.1 Prepare the backer panel in accordance with Practices D 609 or D 1730.
7.2 Attach the desired test pattern to one side of the backer panel with masking tape or adhesive tape.
7.3 Reduce the material being tested to spray viscosity.
7.4 Attach spray gun to a suitable compressed air supply line and adjust air pressure for consistent fan spray.
7.5 Position the backer panel so that the long side is vertical. The panel shou
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