ASTM D 1640 / D 1640M - 14. Standard Test Method for Drying, Curing, or Film Formation of Organic Coatings

American Society for Testing and Materials (ASTM). Current edition approved Dec. 1, 2014. Published February 2015. Originally approved in 1959. Last previous edition approved in 2009 as D1640 – 03 (2009). 4 p.
These test methods can be used to determine the various stages and rates of drying, curing, and film formation of organic coatings for comparing types of coatings, assessing the impact of compositional changes on drying time, or for assessing drying/curing time in the shop or field. Low temperature can significantly slow the drying rate of coatings so low temperature curing agents, catalysts and/or accelerators are often available to aid drying and film formation under cooler temperatures. Method B is designed to evaluate these components and/or to determine the effect of cooler temperatures on drying rates. Conversely, the drying/curing rate of certain coatings can be accelerated under elevated temperature/humidity conditions, while others may be adversely impacted by elevated humidity.
Method C is designed to evaluate the effects of elevated temperature and relative humidity conditions on drying, curing, and film formation of paints and coatings. The terms dry or drying, cure or curing, and film formation are used interchangeably throughout this standard.
Test Methods A, B and C are limited to a comparison of paints/coatings applied to smooth, non-absorbent substrates and do not reflect the effect of absorption of the paint vehicle into the substrate material.