5.1 The drying times of a coating are significant in determining when a freshly painted room, floor or stair may be put back in use or a coated article handled or packaged. Slow drying may result in dirt pick-up or, on an exterior surface, moisture may cause a nonuniform appearance.

5.2 These test methods are used to determine the various stages of drying or curing in the dry-film formation of organic coatings using mechanical devices for the purpose of comparing types of coatings or ingredient changes, or both. To evaluate the stages of drying in a quantitative manner, use of instrumentation under environmental controlled conditions is strongly recommended. These devices also offer a method of determining drying characteristics of coatings that can not be ascertained within the standard 8-h work day.

5.3 When evaluating drying characteristics of baking systems, the circular drying time devices offer a method to determine quantitatively drying times of coatings at room temperature and elevated conditions. Maximum temperatures would be limited by considerations such as the affect of temperature on the motor lubrication or structural components of the device.

5.4 The straight line drying time devices offer a method to determine quantitatively drying times of coatings tested simultaneously using one recorder.

5.5 This method is useful in comparing the behavior of coatings during drying of the same generic type. Determination of actual drying times should be conducted following procedures outlined in Test Method D1640 or ISO 9117-3.

1.1 These test methods describe the determination of several stages and the rate of dry-film formation of organic coatings using straight line and circular mechanical drying-time recording devices. The use of mechanical recorders is valuable in comparing the drying behavior of coatings of the same generic type, allowing that one coating may form a gel or resist tearing at a faster rate than another.

1.2 Drying time measured using the mechanical recorders may differ from those found using conventional methods, such as Test Method D1640 or ISO 9117-3 (formerly ISO 1517).

1.3 The values stated in SI are to be regarded as the standard. The values given in parentheses are provided for information only.

1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.