ASTM D1640 Standard Test Methods for Drying, Curing, or Film Formation of Organic Coatings

    ASTM D1640 Introduction

    ASTM D1640 specifies test procedures for measuring the drying, curing, or film-forming times of organic coatings such as paints, varnishes, and other protective finishes. The original standard was adopted to meet the increasing demand for standardized assessment of drying characteristics under laboratory and field tests. Because organic coatings undergo distinct processes, the standard provides a systematic approach to calculate each step with consistent precision. These parameters influence not only application efficiency, but also adhesion, retention of gloss, chemical resistance, and mechanical strength. The standard provides comprehensive coverage of industries in product development, quality assurance, and regulatory compliance, and serves as a necessary reference in coating technology.

    Read more

    Get Certified ASTM D1640 for Coating Performance Assurance

    ASTM D1640 certification establishes that the drying and curing properties of organic coatings have been determined with respect to acknowledged industry tests. Certified testing enhances consistency in the products, aids in the technical data sheet, and also builds customer confidence.

    Scope of ASTM D1640

    • It is used with solvent-based, water-based, and reactive coating systems.
    •  It establishes the different levels of drying under laboratory conditions.
    •  It assists in the formation of the coating development and quality control of production.

    ASTM D1640 Equipment and Sample Preparation

    Specimen PreparationShould be fitted with a floating roller fitting that can provide uniform peel geometry.
    Specimen DimensionsTypical panels measure 100 mm × 150 mm with a uniform film thickness of 25-50 microns, depending on product specification.
    Conditioning EquipmentPanels will be cured with regulated laboratory conditions, usually at 23 ± 2°C and 50 ± 5% relative humidity, to maintain the same results.

    Applications of ASTM D1640

    • Evaluation of architectural and industrial paints.
    • Protective Coating and Automotive.
    •  Wood finishes and varnishes.
    • Coatings for aerospace and marine.
    • Coating manufacturing plant quality control.

    ASTM D1640 Common Challenges and Troubleshooting

    Some of the challenges that are common are variation of film thickness, variation of environment, poor preparation of substrate, and subjectivity in the interpretation of drying stages. A change in humidity and temperature has a great impact on the drying period. Reliability and repeatability are enhanced by maintaining controlled environmental conditions and applying calibrated thickness applicators.

    Read more

    ASTM D1640 Aggregate Testing Technique, Process, and Data Collection

    An even layer of coating film is sprayed onto a panel that was prepared and put in a controlled environment. Physical tests are carried out at intervals to ascertain the stages of drying. Observations are noted together with the time elapsed and environmental conditions. Several panels can be tested to provide consistency and statistical reliability.

    ASTM D1640 Testing Procedure and Requirements

    Surface Dry TimeThe time to be determined by rubbing an uncontaminated finger or cotton swab against the coating at intermittent intervals; the surface must not stick in one spot but must force the layer beneath it.
    Through-Dry TimePressing the coated panels with the thumb or a specified weight, the film should not be deformed or adhesive to pressure.
    Dry-Hard or Cure TimeBy firmly pushing or bending the coated panel, the film must not crack, impress, or peel when stressed.

    ASTM D1640 Analysis Results and Interpretation

    Reduced drying periods mean that the film is formed or it cures faster, which could be an improvement to productivity. Long drying periods can indicate a problem in the formulation or sensitivity to the environment. Product-to-product comparison enables the manufacturers to optimize solvent content, resin chemistry, and curing mechanisms. Technical specifications often contain results that directly inform application practices.

    Read more

    ASTM D1640 Problem & Solution

    Random drying or curing in nature may postpone manufacturing times, bring about surface flaws, or lead to poor performance of the coating. ASTM D1640 measures drying phases with precision that gives a manufacturer the ability to streamline the formulations and guarantee consistent performance of the coating application.

    Updated on September 17, 2026

    Davis Scott
    About Author
    Davis Scott
    Davis Scott is an Electrical and Electronics Engineer specializing in multidisciplinary validation, quality assurance, and comprehensive electro-mechanical testing.
    Know More
    Testimonials
    Real results
    Engineers trust us with what matters most
    Why Choose Matestlab?
    Matestlab is a unified testing services partner based in the USA. Matestlab offers raw material and product testing services through accredited, expert laboratories primarily based in the USA. Matestlab supports physical, thermal, chemical, electrical, mechanical, environmental, and characterization testing needs through its global network of 2200+ accredited testing laboratories. Matestlab's in-house materials science experts curate and design comprehensive testing programs matched to the sample material and specific testing need, with regulatory requirements and confidentiality in mind.

    If you are looking for a managed and trusted testing partner to achieve your research goals, feel free to schedule a meeting with us or send us a request at connect@matestlabs.com to learn more about our services. For a quick quote, call us at (302)244-7710. We are happy to serve you.
    Start Your Testing
    Project Today
    Define your requirements and get access to
    specialized laboratories ready to deliver results
    Start Testing
    Contact us
    Partners with us
    Clients
    Vendors
    Process for testing
    • STEP 01

      You share your testing requirements

    • STEP 02

      You share your sample(s)

    • STEP 03

      We deliver your test reports

    Get your testing done

    Let us know your testing requirements and we will be right back with a solution.

      Let us root for each other. Collaborate to grow, expand, and accelerate our businesses.

      Partner with us