ASTM D4414-95

Standard Practice for Measurement of Wet Film Thickness by Notch Gages

SCOPE
1.1 This practice describes the use of thin rigid metal notched gages, also called step or comb gages, in the measurement of wet film thickness of organic coatings, such as paint, varnish, and lacquer.
1.2 Notched gage measurements are neither accurate nor sensitive, but they are useful in determining approximate wet film thickness of coatings on articles where size(s) and shape(s) prohibit the use of the more precise methods given in Methods D1212.
1.3 This practice is divided into the following two procedures:
1.3.1 Procedure A--A square or rectangular rigid metal gage with notched sides is used to measure wet film thicknesses ranging from 3 to 2000 µm (0.5 to 80 mils 1). Such a gage is applicable to coatings on flat substrates and to coatings on articles of various sizes and complex shapes where it is possible to get the end tabs of the gage to rest in the same plane on the substrate.
1.3.2 Procedure B--A circular thin rigid metal notched gage is used to measure wet film thicknesses ranging from 25 to 2500 µm (1 to 100 mils ). Such a gage is applicable to coatings on flat substrates and to coatings on objects of various sizes and complex shapes.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2000
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.23 - Physical Properties of Applied Paint Films

Relations

• Referred By: ASTM D3276-21 - Standard Guide for Painting Inspectors (Metal Substrates)
• Effective Date: 01-Jan-2001
• Referred By: ASTM D7394-18(2023) - Standard Practice for Rheological Characterization of Architectural Coatings using Three Rotational Bench Viscometers
• Effective Date: 01-Jan-2001
• Referred By: ASTM E1797-12(2017)e1 - Standard Specification for Reinforced Liquid Coating Encapsulation Products for Leaded Paint in Buildings
• Effective Date: 01-Jan-2001
• Referred By: ASTM D823-18(2022) - Standard Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels
• Effective Date: 01-Jan-2001
• Referred By: ASTM D1640/D1640M-14(2022) - Standard Test Methods for Drying, Curing, or Film Formation of Organic Coatings
• Effective Date: 01-Jan-2001
• Referred By: ASTM D8367-21 - Standard Practice for Making a Laboratory Pavement Marking Sample Using a Pavement Marking and Drop-on Particles
• Effective Date: 01-Jan-2001
• Referred By: ASTM F2831-19 - Standard Practice for Internal Non Structural Epoxy Barrier Coating Material Used In Rehabilitation of Metallic Pressurized Piping Systems
• Effective Date: 01-Jan-2001
• Referred By: ASTM D7377-09(2018) - Standard Practice for Evaluating the Water Wash-Off Resistance of Traffic Paints using a Water Faucet
• Effective Date: 01-Jan-2001
• Referred By: ASTM E1795-20a - Standard Specification for Non-Reinforced Liquid Coating Encapsulation Products for Leaded Paint in Buildings
• Effective Date: 01-Jan-2001
• Referred By: ASTM D7538-09(2018) - Standard Practice for Evaluating the Water Wash-Off Resistance of Traffic Paints Using an Atomizing Spray Device
• Effective Date: 01-Jan-2001
• Referred By: ASTM D6237-19 - Standard Guide for Painting Inspectors (Concrete and Masonry Substrates)
• Effective Date: 01-Jan-2001
• Referred By: ASTM D5498-12a(2018) - Standard Guide for Developing a Training Program for Personnel Performing Coating and Lining Work Inspection for Nuclear Facilities
• Effective Date: 01-Jan-2001
• Referred By: ASTM D711-23 - Standard Test Method for No-Pick-Up Time of Pavement Markings
• Effective Date: 01-Jan-2001
• Referred By: ASTM D5064-16a(2021) - Standard Practice for Conducting a Patch Test to Assess Coating Compatibility
• Effective Date: 01-Jan-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4414 – 95
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Practice for
Measurement of Wet Film Thickness by Notch Gages
This standard is issued under the fixed designation D 4414; 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.
1. Scope 3. Summary of Practice
1.1 This practice describes the use of thin rigid metal 3.1 The material is applied to the articles to be coated and
notched gages, also called step or comb gages, in the measure- the wet film thickness measured with a notched gage.
ment of wet film thickness of organic coatings, such as paint, 3.2 Procedure A—A square or rectangular thin rigid metal
varnish, and lacquer. gage with notched sides, having tabs of varying lengths, is
1.2 Notched gage measurements are neither accurate nor pushed perpendicularly into the film. After removal from the
sensitive, but they are useful in determining approximate wet film, the gage is examined and the film thickness is determined
film thickness of coatings on articles where size(s) and shape(s) to lie between the clearance of the shortest tab wet by the film
prohibit the use of the more precise methods given in Methods and the clearance of the next shorter tab not wetted by the film.
D 1212. 3.3 Procedure B—A circular thin rigid metal gage having
1.3 This practice is divided into the following two proce- spaced notches of varying depths around its periphery is rolled
dures: perpendicularly across the film. After removal from the film,
1.3.1 Procedure A—A square or rectangular rigid metal the gage is examined and the film thickness is determined as
gage with notched sides is used to measure wet film thick- being between the clearance of the deepest face wetted and the
nesses ranging from 0.5 to 80 mils (13 to 2000 μm). Such a clearance of the next deepest notch face not wetted by the film.
gage is applicable to coatings on flat substrates and to coatings
4. Significance and Use
on articles of various sizes and complex shapes where it is
possible to get the end tabs of the gage to rest in the same plane 4.1 Wet film thickness measurements of coatings applied on
articles can be very helpful in controlling the thickness of the
on the substrate.
1.3.2 Procedure B—A circular thin rigid metal notched gage final dry coating, although in some specifications the wet film
thickness is specified. Most protective and high performance
is used to measure wet film thicknesses ranging from 1 to 100
mils (25 to 2500 μm). Such a gage is applicable to coatings on coatings are applied to meet a requirement or specification for
dry film thickness for each coat or for the completed coating
flat substrates and to coatings on objects of various sizes and
complex shapes. system, or for both.
4.2 There is a direct relationship between dry film thickness
1.4 The values stated in inch-pound units are to be regarded
as the standard. The values given in parentheses are for and wet film thickness. The wet film/dry film ratio is deter-
mined by the volume of volatiles in the coating as applied,
information only.
including permitted thinning. With some flat coatings the dry
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the film thickness is higher than that calculated from the wet film
thickness. Consequently, the results from the notch gage are
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- not to be used to verify the nonvolatile content of a coating.
4.3 Measurement of wet film thickness at the time of
bility of regulatory limitations prior to use.
application is most appropriate as it permits correction and
2. Referenced Documents
adjustment of the film by the applicator at the time of
2.1 ASTM Standards: application. Correction of the film after it has dried or
D 1212 Test Methods for Measurement of Wet Film Thick- chemically cured requires costly extra labor time, may lead to
ness of Organic Coatings contamination of the film, and may introduce problems of
adhesion and integrity of the coating system.
4.4 The procedures using notched gages do not provide as
This practice is under the jurisdiction of ASTM Committee D-1 on Paint and
accurate or sensitive measurements of wet film thickness as do
Related Coatings, Materials, and Applications and is the direct responsibility of
the Interchemical and Pfund gages described in Methods
Subcommittee D01.23 on Physical Properties of Applied Paint Films.
D 1212. Notch gages may, however, be used on nonuniform
Current edition approved Nov. 10, 1995. Published January 1996. Originally
e1
published as D 4414 – 84. Last previous edition D 4414 – 84 (1990) . surfaces, like concrete block, that are too rough to use the
Annual Book of ASTM Standards, Vol 06.01.
D 4414
Interchemical and Pfund gages. Also notched gages can be By 0.5 mil (13 μm) between 0 and 6 mils (0 to 150 μm),
very useful in the shop and field for determining the approxi- By 1 mil (25 μm) between 6 and 10 mils (150 to 250 μm),
mate thickness of wet films over commercial articles where By 2 mils (50 μm) between 10 and 30 mils (250 to 750 μm),
size(s) and shape(s) are not suitable for measurements by other and
types of gages. Examples of such items are ellipses, thin edges, By 5 mils (125 μm) over 30 mils (750 μm).
and corners.
8. Procedure
4.5 An operator experienced in the use of a notched gage
8.1 Apply the coating material to a rigid substrate and test
can monitor the coating application well enough to ensure the
with the gage immediately. The gage must be used immediately
minimum required film thickness will be obtained.
following application of the coating. Some coatings lose
4.6 Application losses, such as overspray, loss on transfer,
solvents quickly and spray application increases the speed. The
and coating residue in application equipment, are a significant
resulting rapid reduction in wet film thickness c
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