[TT-C-490D]
Specification covers cleaning methods
and pre-treatment processes.
Type I: Intended as a general
all-purpose pretreatment prior to painting.
Type II and IV: Intended primarily
for use where metal parts are to be formed after painting.
Type III: Intended for use where
size and shape preclude using type I, II or IV and where items containing
mixed metal components are assembled prior to treatment.
Note: Cleaning material shall
not contain any chemical which is classified in the Clean Air Act Amendments
of 1990 as a Class I or Class II ozone depleting substance.
Light coating for use as a paint base.
Cleaning methods:
Method I: Mechanical or abrasive
cleaning (for ferrous surfaces only).
Method II: Solvent cleaning.
Method III: Hot Alkaline (for
ferrous surfaces only).
Method IV: Emulsion.
Method V: Alkaline derusting
(for ferrous surfaces only).
Method VI: Phosphoric acid.
Type I: Zinc phosphate. Class
1 - spray application (150mg/sq. ft. min. - 500mg/sq. ft. max). Class 2A
- Immersion or Dip application (300mg/sq. ft. min/500mg/sq. ft. max). Class
2B - Immersion or Dip application (600mg/sq. ft. min to 1000mg/sq. ft.
max.).
Type II: Aqueous Iron Phosphate
(35mg/sq. ft. min.)
Type III: (.0003-.0005")
Organic pretreatment coating (unless otherwise specified, MIL-C-8514 of
DOD-P-15328).
Type IV: Non-aqueous iron phosphate.
(35mg/sq. ft. min.)
Type V: Zinc phosphate (500mg/sq.
ft. min. - 1100mg/sq. ft. max.).
|