Sulfuric Anodizing  (22 Foot tanks) Color will vary with alloy. Aluminum with low alloying elements will show practically no color change. Best coating on aluminum for dyeing. Can be dyed practically any color or shade (Black, blue, red, gold, orange, green etc.).Salt spray requirement is 336 hours (5% NaCI solution) per method B-117 of ASTM. Minimum weight for type II coatings: Class 1-1,000 Milligrams/sq.ft.
Spec.	Thickness	Comment
MIL-A-8625F	0.000070" - 0.0010"
Type II		All aluminum alloys, but do not use where solution will entrap.
Type IIB	Light coating
Class 1		Non-dyed
Class 2		Dyed
Unless "clear" is specified on a Class 1, non-dyed coating, proper sealing will result in a yellow pale green appearance. FED-STD-No. 595 may be used as a guide for specifying color (approximate comparison only).