Test for Tack-Free Time of Elastomeric Sealants ASTM C679

Test for Tack-Free Time of Elastomeric Sealants ASTM C679

ASTM C679 determines the Tack-Free Time of Elastomeric Sealants, a type of mending glue used in construction. In this test, the sealant specimen is lightly touched with a polythene film at regular intervals to determine the time it takes for the sealant to dry.


    ASTM C679 is used to test the quality of the curing sealants by measuring Tack-free time. The tack-free time is a measure of the surface cure time, the time at which the coating properly adheres and is capable of providing maximum protection. Different locations have different temperatures and humidity. The sealant is tested for all the possible temperature and humidity conditions in which the sealant might be used.

    The tack-free time is correlated to a variety of useful parameters such as the time interval before the sealant (1) resists damage due to light surface contact, (2) resists picking up dirt, (3) resists impinging rainfall.

    Test Procedure:

    In ASTM C679, a polythene film is placed on a sealant and a weight of 30 g is placed on the polythene film. After 30 seconds, both the weight and the polythene film are lifted, and the polythene strip is examined for any sealant. With some sealants, a very thin film of oil or sealant always gets pasted on the polythene film. In such situations, thin film is ignored and the data is recorded regardless.

     Specimen size:

    The test specimen should be a factory-sealed can of compound (minimum contents, 450 mL) with an appropriate curing agent, or a standard cartridge, factory filled and sealed.


    Following things are reported:
    • Tack-free time, the time until no sealant was picked up on the polyethylene film.
    • Whether the film was clean or the film contained a thin layer of plasticizers.
    • The temperature and humidity conditions, which are different from the standard conditions.


    Core Materials Testing Services


    A variety of microscopy and spectroscopy tools available for precise measurements from the nano to the meter scale.

    Metrology Testing Services


    TEM SIMS Profilometry

    Materials Testing

    ASTM and ISO standard and custom chemical, mechanical, thermal, corrosion tests, etc. for all materials metals, ceramic or polymers.

    Materials Testing Services


    Nondestructive Testing Electrical Testing Chemistry Analysis

    Product Testing

    Thousands of tests for product quality and reliability under heat, humidity, temperature shock, vibration, drop, electrostatic discharge.

    Product Testing Services


    Vibration Testing Humidity Testing Accelerated Aging

    Looking for Material Testing?

    We have already delivered 500+ Material Tests results to top companies

      Send us a request

        Process for testing


          STEP 01

          You share material and testing requirements with us


          STEP 02

          We ensure your sample pick-up in an ensured manner


          STEP 03

          We deliver test report to your inbox

          Let’s work together!

          Share your testing requirements with us and we will be happy to assist you.

          idea icon

          Want to connect with an expert before you leave?