This specification covers highly pigmented primers that contain zinc dust as the major pigment component (minimum 50% by weight in the dry film) and are defined by their ability to galvanically protect ferrous substrates.
The vehicle type may be inorganic (Type I) or organic (Type II).
Each primer type (I and II) is classified according to the level of exterior performance at a severe marine site. Laboratory performance criteria are also included.
This specification does not cover weldable preconstruction primers.
This primer, when applied over properly prepared steel substrates, can provide effective corrosion resistance in a wide range of environmental zones (see Note 11.1). In some cases a topcoat may be required.
USE OF SPECIFICATION:
1) Primers meeting these specifications are categorized according to vehicle type, and performance level.
2) If no vehicle type is specified, either Type I, inorganic, or Type II, organic, is acceptable (see Section 2.5).
3) If no performance level is specified, Level 1 is assumed (see Section 2.8).
COMPOSITION: The coatings described in this specification consist of zinc dust, functional additives, and an organic or inorganic binder, with appropriate solvents.
SELECTION OF PRIMER: The selection and use of these primers are given in SSPC-PS Guide 12.00 and SSPC- PS 12.01. An exception to these guides regards zinc dust loading.
PIGMENTATION
The major pigment component in these coatings is zinc dust of the type described in ASTM D 520.
Other pigment components may include extenders, curing aids, tinting colors, suspension and pot life control agents.
VEHICLE TYPES: The vehicles used for these coatings may be as follows:
Type I: inorganic; solvent or water reducible; self or post cure
Type II: organic; solvent or water reducible
VOLATILE ORGANIC COMPOUND (VOC) CONTENT:
The VOC content of the primer shall be determined from the coating as applied, after recommended thinning.
COMPONENTS: These zinc-dust primers may consist of one, two, or three components.
EXTERIOR PERFORMANCE: The primer shall be classified as follows according to the minimum number of months of successful performance at a severe marine site (see Section 6.5):
Type l: Inorganic Zinc Primer
Level 1: 12 months
Level 2: 30 months
Type II: Organic Zinc Primer
Level 1: 12 months
Level 2: 30 months
