TECHNICAL STANDARD
ASTM D4752
Standard Practice for Measuring MEK Resistance of Ethyl Silicate (Inorganic) Zinc-Rich Primers by Solvent Rub
ASTM International
20(2024)
Current
WHAT DOES THIS STANDARD COVER?
ASTM D4752 provides a practice for assessing the methyl ethyl ketone (MEK) resistance of ethyl silicate inorganic zinc-rich primers using a solvent-rub technique. For applicable inorganic zinc-rich primers, MEK resistance can provide an indication of the degree of cure and can be used as part of inspection before subsequent coating operations where required by the project specification or coating manufacturer’s requirements. The practice should not be described as an adhesion test and does not directly measure coating adhesion strength.
WHY IS IT RELEVANT?
Ethyl silicate inorganic zinc-rich primers may require verification that an appropriate degree of cure has been achieved before overcoating. ASTM D4752 provides inspectors with a recognised method of assessing MEK resistance for these applicable coatings. The required resistance or cure criterion for proceeding with a particular coating system should be established from the relevant project specification, coating manufacturer’s documentation and agreed inspection requirements. The standard should not be interpreted as providing one universal pass/fail value suitable for every zinc silicate coating system.
KEY INSPECTION CONSIDERATIONS
ASTM D4752 is specifically concerned with assessing the MEK resistance of ethyl silicate inorganic zinc-rich primers by solvent rubbing. The test is used as an indication of the degree of cure of the inorganic zinc-rich primer. Cure of these materials is influenced by conditions including temperature and relative humidity. The test should be performed and interpreted using the applicable procedure and the project or coating-manufacturer requirements.
WHAT THE STANDARD SHOULD NOT BE USED TO ASSUME
ASTM D4752 should not be treated as a general solvent-rub test for every coating type. Its scope is specifically associated with ethyl silicate inorganic zinc-rich primers. The test is an indication of cure or solvent resistance. It is not an adhesion test and does not establish pull-off strength. There is no universal ASTM D4752 pass requirement that can be assumed for every product and project. Acceptance should be established from the applicable project specification and coating-manufacturer requirements.
PRACTICAL INSPECTION APPLICATION
ASTM D4752 may be used during inspection of inorganic zinc-rich primer application where verification of cure is required before subsequent coating operations. The inspector should confirm that the product is within the scope of the method, identify the specified acceptance requirement and record the test location and result. Where the coating is an organic coating rather than an ethyl silicate inorganic zinc-rich primer, the applicable solvent-rub method should be confirmed rather than assuming ASTM D4752 applies.
RELATED TECHNICAL TOPICS
Testing & Analysis Zinc Silicate Coatings Coating Inspection Coating Cure
RELATED PIL GUIDANCE
MEK solvent-rub assessment can provide a practical indication of cure for applicable ethyl silicate inorganic zinc-rich primers before overcoating.
RELATED EXPERTISE
Testing & Analysis Coating Inspection Technical Consultancy
ABOUT THIS TECHNICAL SUMMARY
Paint Inspection Ltd provides this information to help inspectors, engineers, asset owners and contractors understand the practical relevance of commonly referenced protective coatings standards. This page is PIL technical guidance and does not reproduce or replace the published standard. Users should refer to the current published standard, project specification, coating manufacturer requirements and other applicable contract documents when establishing project requirements or acceptance criteria.
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OFFICIAL STANDARD
PIL technical summaries are intended to explain the inspection relevance of industry standards and do not replace the published document.
STATUS AND SOURCE VERIFICATION
ASTM D4752-20(2024) verified against ASTM International in September 2026 as the active edition covering measurement of MEK resistance of ethyl silicate (inorganic) zinc-rich primers by solvent rub. ASTM identifies ASTM D5402 as the preferred solvent-rub practice for organic coatings.