This specification covers the requirements for an air-drying solvent-based alkyd coating system consisting of two or more coats of alkyd intended for use over blast cleaned steel. (See Note 13.1.) The specification covers both the system and the individual coating requirements. The requirements are based primarily on the performance of the coating system.
The coating system is suitable for exposure in Environmental Zones 1A (interior, normally dry), 1B (exterior, normally dry), 2A (frequently wet by fresh water, excluding immersion), and 2B (frequently wet by salt water, excluding immersion). (See Note 13.2.) The coating system is classified according to the drying time (fast, medium, slow) of the slowest drying coating layer.
This multi-coat alkyd coating system specification does not cover coating systems comprised of water-reducible alkyds.
DRYING TIME: The coating system shall be classified as Type 1 (fast drying), Type 2 (medium drying), or Type 3 (slow drying). See Section 6.4 regarding test methods and criteria for drying time.
FINISH COAT GLOSS: The finish coat shall be designated as flat, semigloss, or gloss in accordance with Section 7.3.
