ASTM D4414-95(2020)
(Practice)Standard Practice for Measurement of Wet Film Thickness by Notch Gages
Standard Practice for Measurement of Wet Film Thickness by Notch Gages
SIGNIFICANCE AND USE
4.1 Wet film thickness measurements of coatings applied on articles can be very helpful in controlling the thickness of the final dry coating, although in some specifications the wet film thickness is specified. Most protective and high performance coatings are applied to meet a requirement or specification for dry film thickness for each coat or for the completed coating system, or for both.
4.2 There is a direct relationship between dry film thickness and wet film thickness. The wet film/dry film ratio is determined by the volume of volatiles in the coating as applied, including permitted thinning. With some flat coatings the dry film thickness is higher than that calculated from the wet film thickness. Consequently, the results from the notch gage are not to be used to verify the nonvolatile content of a coating.
4.3 Measurement of wet film thickness at the time of application is most appropriate as it permits correction and adjustment of the film by the applicator at the time of application. Correction of the film after it has dried or chemically cured requires costly extra labor time, may lead to 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 accurate or sensitive measurements of wet film thickness as do the Interchemical and Pfund gages described in Test Methods D1212. Notch gages may, however, be used on nonuniform surfaces, like concrete block, that are too rough to use the Interchemical and Pfund gages. Also notched gages can be very useful in the shop and field for determining the approximate thickness of wet films over commercial articles where size(s) and shape(s) are not suitable for measurements by other types of gages. Examples of such items are ellipses, thin edges, and corners.
4.5 An operator experienced in the use of a notched gage can monitor the coating application well enough to ensure the minimum required film thickness ...
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 Test 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4414 − 95 (Reapproved 2020)
Standard Practice for
Measurement of Wet Film Thickness by Notch Gages
This standard is issued under the fixed designation D4414; 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.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This practice describes the use of thin rigid metal
notched gages, also called step or comb gages, in the measure-
2. Referenced Documents
ment of wet film thickness of organic coatings, such as paint,
2.1 ASTM Standards:
varnish, and lacquer.
D1212 Test Methods for Measurement of Wet Film Thick-
1.2 Notched gage measurements are neither accurate nor
ness of Organic Coatings
sensitive, but they are useful in determining approximate wet
filmthicknessofcoatingsonarticleswheresize(s)andshape(s)
3. Summary of Practice
prohibit the use of the more precise methods given in Test
3.1 The material is applied to the articles to be coated and
Methods D1212.
the wet film thickness measured with a notched gage.
1.3 This practice is divided into the following two proce-
3.2 Procedure A—A square or rectangular thin rigid metal
dures:
gage with notched sides, having tabs of varying lengths, is
1.3.1 Procedure A—A square or rectangular rigid metal
pushed perpendicularly into the film. After removal from the
gage with notched sides is used to measure wet film thick-
film, the gage is examined and the film thickness is determined
nesses ranging from 3 to 2000 µm (0.5 to 80 mils 1). Such a
to lie between the clearance of the shortest tab wet by the film
gage is applicable to coatings on flat substrates and to coatings
and the clearance of the next shorter tab not wetted by the film.
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
3.3 Procedure B—A circular thin rigid metal gage having
on the substrate.
spaced notches of varying depths around its periphery is rolled
1.3.2 ProcedureB—Acircular thin rigid metal notched gage
perpendicularly across the film. After removal from the film,
is used to measure wet film thicknesses ranging from 25 to
the gage is examined and the film thickness is determined as
2500 µm (1 to 100 mils ). Such a gage is applicable to coatings
being between the clearance of the deepest face wetted and the
onflatsubstratesandtocoatingsonobjectsofvarioussizesand
clearance of the next deepest notch face not wetted by the film.
complex shapes.
4. Significance and Use
1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
4.1 Wet film thickness measurements of coatings applied on
only.
articles can be very helpful in controlling the thickness of the
final dry coating, although in some specifications the wet film
1.5 This standard does not purport to address all of the
thickness is specified. Most protective and high performance
safety concerns, if any, associated with its use. It is the
coatings are applied to meet a requirement or specification for
responsibility of the user of this standard to establish appro-
dry film thickness for each coat or for the completed coating
priate safety, health, and environmental practices and deter-
system, or for both.
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
4.2 There is a direct relationship between dry film thickness
dance with internationally recognized principles on standard-
and wet film thickness. The wet film/dry film ratio is deter-
ization established in the Decision on Principles for the
mined by the volume of volatiles in the coating as applied,
Development of International Standards, Guides and Recom-
including permitted thinning. With some flat coatings the dry
film thickness is higher than that calculated from the wet film
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.23 on Physical Properties of Applied Paint Films. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJune1,2020.PublishedJuly2020.Originallyapproved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
in 1984. Last previous edition approved in 2013 as D4414 – 95 (2013). DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D4414-95R20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4414 − 95 (2020)
thickness. Consequently, the results from the notch gage are
not to be used to verify the nonvolatile content of a coating.
4.3 Measurement of wet film thickness at the time of
application is most appropriate as it permits correction and
adjustment of the film by the applicator at the time of
application. Correction of the film after it has dried or
chemically cured requires costly extra labor time, may lead to
FIG. 1 Rectangular Notched Gage
contamination of the film, and may introduce problems of
adhesion and integrity of the coating system.
7.1.1 Each notched side shall consist of a series of tabs
4.4 The procedures using notched gages do not provide as
(between notches) varying in length and located in a line
accurate or sensitive measurements of wet film thickness as do
between two end tabs equal in length and longest in the row.
the Interchemical and Pfund gages described in Test Methods
7.1.2 As an example, the tabs on one row of a gage may
D1212. Notch gages may, however, be used on nonuniform
differ in length as follows:
surfaces, like concrete block, that are too rough to use the
By 13 µm (0.5 mil) between 0 to 150 µm (0 and 6 mils),
Interchemical and Pfund gages. Also notched gages can be
By 25 µm (1 mil) between 150 to 250 µm (6 and 10 mils),
very useful in the shop and field for determining the approxi-
By 50 µm (2 mils) between 250 to 750 µm (10 and 30 mils),
mate thickness of wet films over commercial articles where
and
size(s) and shape(s) are not suitable for measurements by other
By 125 µm (5 mils) over 750 µm (30 mils).
types of gages. Examples of such items are ellipses, thin edges,
8. Procedure
and corners.
8.1 Apply the coating material to a rigid substrate and test
4.5 An operator experienced in the use of a notched gage
withthegageimmediately.Thegagemustbeusedimmediately
can monitor the coating applicati
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.