ASTM D4752-20

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: D4752 − 20
Standard Practice for
Measuring MEK Resistance of Ethyl Silicate (Inorganic)
1
Zinc-Rich Primers by Solvent Rub
This standard is issued under the fixed designation D4752; 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 D4138 Practices for Measurement of Dry Film Thickness of
Protective Coating Systems by Destructive, Cross-
1.1 This practice describes a solvent rub technique for
Sectioning Means
assessing the MEK resistance of ethyl silicate (inorganic)
D5402 Practice for Assessing the Solvent Resistance of
zinc-rich primers. The MEK resistance of some two-
Organic Coatings Using Solvent Rubs
component ethyl silicate zinc-rich primers has been shown to
D7091 Practice for Nondestructive Measurement of Dry
correlate well with the cure of the primer as determined by
2 Film Thickness of Nonmagnetic Coatings Applied to
diffuse reflectance infrared spectroscopy. The technique can
Ferrous Metals and Nonmagnetic, Nonconductive Coat-
be used in the laboratory, field, or in the fabricating shop.
ings Applied to Non-Ferrous Metals
Practice D5402 is the preferred method for organic coatings.
1.2 The values stated in SI units are to be regarded as the
3. Terminology
standard. The values given in parentheses are for information
3.1 Definitions of Terms Specific to This Standard:
only.
3.1.1 double rub, n—the act of rubbing a solvent saturated
1.3 This standard does not purport to address all of the
cloth in one complete forward and backward motion over a
safety concerns, if any, associated with its use. It is the
coated surface.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
4.1 Ethyl silicate zinc-rich primers cure by the reaction of
Specific hazard statements are given in Section 6. Consult
supplier’s Safety Data Sheet(s) for specific hazard information the vehicle with moisture, thereby providing a binder for the
zinc. As relative humidity and temperature vary, so does the
relating to the solvent used.
1.4 This international standard was developed in accor- rate of cure. A certain minimum degree of cure is necessary
prior to topcoating. It has been shown that the degree of cure
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the of ethyl silicate zinc-rich primers can be measured by the
chemical changes occurring using diffuse reflectance infrared
Development of International Standards, Guides and Recom-
2
mendations issued by the World Trade Organization Technical spectroscopy. This solvent rub test has been shown to corre-
Barriers to Trade (TBT) Committee. late well with the infrared spectroscopic results of some
two-component ethyl silicate inorganic zinc systems.
2. Referenced Documents
4.2 The degree of cure rating (Resistance Rating in Table 1)
3
2.1 ASTM Standards:
required prior to the application of specific topcoats must be
D740 Specification for Methyl Ethyl Ketone
agreed upon before the practice is used.
1
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
5. Reagents and Materials
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.46 on Industrial Protective Coatings.
5.1 Methyl Ethyl Ketone (MEK), in accordance with Speci-
Current edition approved Feb. 1, 2020. Published February 2020. Originally
fication D740.
approved in 1987. Last previous edition approved in 2015 as D4752 – 10 (2015).
DOI: 10.1520/D4752-20.
5.2 100 % Cotton, Shop Cloth, approximately 300 by 300
2
Starr, T. L., Henton, L. E., Lewis, W. S., and Rideout, F. A., “Improved Field
mm (12 by 12 in.) contrasting in color to the primer to be
Reliability of High Performance Coating Systems: Phase II—Develop Procedures
and Criteria in Critical Performance Areas,” available from SSPC: The Society for
evaluated.
Protective Coatings, 800 Trumbull Drive, Pittsburgh, PA 15205, www.sspc.org.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 5.3 Squeeze Bottle.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.4 Proper Safety Equipment, as determined from the sol-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. vent SDS, for example, solvent resistant gloves, respirato
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