AS/NZS 2312:1994

1 - AS/NZS 2312:1994 GUIDE TO THE PROTECTION OF IRON AND STEEL AGAINST EXTERIOR ATMOSPHERIC CORROSION
4 - PREFACE
5 - CONTENTS
8 - FOREWORD
9 - SECTION 1 SCOPE AND GENERAL
9 - 1.1 SCOPE
9 - 1.2 REFERENCED DOCUMENTS
12 - 1.3 DEFINITIONS
12 - 1.4 DESIGNATION OF PROTECTION SYSTEMS
13 - SECTION 2 ATMOSPHERIC ENVIRONMENTS
13 - 2.1 GENERAL
13 - 2.2 ATMOSPHERIC CLASSIFICATIONS (APPLICABLE TO STEEL)
15 - SECTION 3 CORROSION PROTECTION SYSTEMS
15 - 3.1 GENERAL
15 - 3.2 RECOMMENDED COATING SYSTEMS
17 - SECTION 4 PLANNING AND DESIGN FOR CORROSION PROTECTION
17 - 4.1 GENERAL
17 - 4.2 PLANNING
18 - 4.3 DESIGN
18 - 4.3.1 General
19 - 4.3.2 Exposure environment
19 - 4.3.3 Materials of construction
21 - 4.3.4 Major design considerations
22 - 4.3.5 General design considerations
31 - SECTION 5 SURFACE PREPARATION TREATMENTS
31 - 5.1 GENERAL
31 - 5.2 CLEANING WITH SOLVENTS OR ALKALINE SOLUTIONS
32 - 5.3 CLEANING AND PREPARATION USING ACID SOLUTIONS (NON-IMMERSION)
32 - 5.4 ABRASIVE BLAST CLEANING
33 - 5.5 PICKLING
33 - 5.6 PHOSPHATE CONVERSION COATINGS
34 - 5.7 FLAME CLEANING
34 - 5.8 POWER TOOL CLEANING
35 - 5.9 HAND TOOL CLEANING
35 - 5.10 THE REMOVALOF SOLUBLE SALTS
35 - 5.11 THE PROTECTION OF STEEL DURING EXTENDED FABRICATION
36 - 5.12 RUST CONVERSION
37 - SECTION 6 METALLIC COATINGS FOR CORROSION PROTECTION
37 - 6.1 GENERAL
37 - 6.2 HOT-DIP GALVANIZED COATINGS
37 - 6.2.1 General
37 - 6.2.2 Bath sizes
37 - 6.2.3 Design for galvanizing
38 - 6.2.4 Galvanizing process
38 - 6.2.5 Application
39 - 6.2.6 Designations for galvanized coating systems
39 - 6.3 METAL SPRAY COATINGS
39 - 6.3.1 General
39 - 6.3.2 Application
39 - 6.3.3 Sealing
39 - 6.3.4 Composite metal spray / sealer / paint systems
40 - 6.3.5 Designations for metal sprayed and composite coating systems
40 - 6.4 ELECTROPLATED COATINGS
41 - 6.5 THE USE OF ROOFING AND CLADDING MATERIALS
42 - SECTION 7 COATING SYSTEMS FOR CORROSION PROTECTION
42 - 7.1 GENERAL
42 - 7.2 DESIGN CONSIDERATIONS
43 - 7.3 COATING SYSTEM DETAILS
43 - 7.4 SELECTION OFCOLOUR
44 - 7.5 HEAT-RESISTING COATINGS
44 - 7.6 POWDER COATINGS
44 - 7.7 PAINTING STAINLESS STEEL
57 - SECTION 8 PAINTING AND PAINT APPLICATION METHODS
57 - 8.1 GENERAL
57 - 8.2 TYPE OF PAINT
57 - 8.2.1 General
57 - 8.2.2 Mixing and thinning
57 - 8.3 TYPE AND CONDITION OF THE SUBSTRATE
57 - 8.4 ATMOSPHERIC CONDITIONS
58 - 8.5 SEQUENCE OF OPERATIONS
58 - 8.6 METHODS OF APPLICATION
58 - 8.6.1 Spray methods
59 - 8.6.2 Brush application
59 - 8.6.3 Roller application
59 - 8.7 STANDARD OF WORKMANSHIP
60 - 8.8 TIME REQUIREMENTS
60 - 8.8.1 Cleaned surfaces
60 - 8.8.2 Period between coats
60 - 8.8.3 Effects of delays during painting
60 - 8.8.4 Drying time before handling
60 - 8.9 PAINT SPREADING RATE AND THICKNESS
61 - 8.10 PAINT STORAGE
61 - 8.10.1 General
61 - 8.10.2 Shelf life
61 - 8.10.3 Pot life
61 - 8.10.4 Straining
63 - SECTION 9 WRAPPING TAPES FOR CORROSION PROTECTION
63 - 9.1 GENERAL
63 - 9.2 TAPE SYSTEMS
64 - SECTION 10 MAINTENANCE OF PROTECTIVE COATING SYSTEMS
64 - 10.1 GENERAL
64 - 10.2 CRITERIA FOR ASSESSING WHEN TO PAINT OR REPAIR
65 - 10.3 PRETREATMENT BEFORE REPAINTING
65 - 10.3.1 General
65 - 10.3.2 Condition of existing coating system
65 - 10.3.3 Surface contamination
65 - 10.3.4 Environmental protection
66 - 10.3.5 Methods
68 - 10.4 REPAINTING
68 - 10.4.1 General
69 - 10.4.2 Procedure
69 - 10.4.3 Records
70 - 10.5 REPAIRS AND REPAINTING OF WELDED STRUCTURES
71 - SECTION 11 INSPECTION AND TESTING
71 - 11.1 SCOPE
71 - 11.2 AUTHORITY
71 - 11.3 PRELIMINARY DISCUSSIONS
72 - 11.4 DUTIES OF INSPECTORS
72 - 11.4.1 Inspection of paint coatings
74 - 11.4.2 Inspection of metallic coatings
74 - 11.5 FINAL INSPECTION
74 - 11.6 RECORDS AND INSPECTION REPORT
74 - 11.7 GUIDANCE ON THE USE OF THICKNESS GAUGES
74 - 11.7.1 Dry film thickness gauges - non-destructive
74 - 11.7.2 Dry film thickness gauges - destructive
75 - SECTION 12 PREPARATION OF COATING SPECIFICATIONS
75 - 12.1 GENERAL
75 - 12.2 CONTENT OF A SPECIFICATION
75 - 12.2.1 Scope of work
75 - 12.2.2 Surface preparation
76 - 12.2.3 Coating system
76 - 12.2.4 Coating materials - detailed stipulations
77 - 12.2.5 Application of coatings
77 - 12.2.6 Transport arrangements
78 - 12.2.7 Repair of welds and damaged areas
78 - 12.2.8 Inspection procedure requirements
79 - 12.2.9 Warranties
80 - SECTION 13 HEALTH AND SAFETY
80 - 13.1 GENERAL
80 - 13.2 THE PAINTED SURFACE
80 - 13.3 FLAMMABILITY
80 - 13.4 EYE PROTECTION
80 - 13.5 RESPIRATORS
80 - 13.6 NOISE
80 - 13.7 HANDLING
81 - 13.8 WORKING IN A CONFINED SPACE
81 - 13.9 SURFACE PREPARATION
81 - 13.10 APPLICATION OF PAINT
82 - 13.11 STORAGE OF PAINT
82 - 13.12 WELDING
82 - 13.13 BURNING OF PAINTED SURFACES
83 - APPENDIX A - GUIDANCE ON THE USE OF THIS STANDARD
83 - A1 GENERAL
83 - A2 CHECK LIST FOR THE COATING OF NEW STRUCTURES
85 - A3 CHECK LIST FOR THE MAINTENANCE PAINTING OF EXISTING STRUCTURES
86 - A4 EXAMPLES OF THE USE OF THIS STANDARD
88 - APPENDIX B - ADVICE ON ATMOSPHERIC CORROSION OF STEEL IN AUSTRALASIAN CLIMATES
92 - APPENDIX C - DESCRIPTION OF PAINT TYPES
92 - C1 SCOPE
99 - APPENDIX D - ECONOMICS OF CORROSION PROTECTION
99 - D1 GENERAL
99 - D2 INITIAL COSTS AND ECONOMICS OF PROTECTIVE TREATMENTS
99 - D2.1 Surface preparation
100 - D2.2 Paint application
100 - D2.3 Galvanizing
100 - D2.4 Inspection
100 - D2.5 Paint coverage
103 - D3 ECONOMIC EVALUATION OF PROTECTIVE TREATMENTS
103 - D3.1 General
103 - D3.2 A simple method of economic evaluation
103 - D3.3 Present-value method
104 - D3.4 Equivalent-annual-cost method
104 - D3.5 Final evaluation

Gives general and specific information on coating systems for the short-, medium-, and long-term protection of structural steelwork. The following aspects are covered in detail: atmospheric environments, planning and design, surface preparation treatments, metallic and paint coatings, maintenance of coating systems, inspection and testing, and preparation of coating specifications. The Standard contains comprehensive details of modern paint systems, including properties and typical applications, and gives advice on the selection of appropriate coating systems.

This Standard provides guidelines for the selection and specification of coating systems for the protection of iron and steel against exterior atmospheric corrosion. The Standard specifically covers the following subjects:(a) Guidance on the use of the Standard.(b) Atmospheric environments and their classification.(c) Corrosion protection system options.(d) Planning and design for corrosion protection.(e) Surface preparation treatments.(f) Metallic coatings.(g) Paint coating systems and methods of paint application.(h) Wrapping tapes for corrosion protection.(i) Maintenance of protective coating systems.(j) Inspection and testing.(k) Guidance on the preparation of coating specifications.(l) Health and safety requirements.(m) Economics of corrosion protection.This Standard covers the protection of structural steelwork against exterior atmospheric corrosion and also the protection of items of equipment manufactured from steel which are exposed to exterior atmospheric conditions.The Standard does not apply to the protection of steelwork which is completely immersed in water or soil, or which is subject to atmospheres severely contaminated with acidic or other chemical vapours such as may be encountered in some chemical manufacturing plants, or to the protection of ships. Protective systems for such exposures may require additional systems dependent upon the nature of the environment.The systems recommended in this Standard can also be used on internal structures where wet or damp areas exist. Where internal steel structures are to be painted for aesthetic reasons, and the environment is not aggressive, reference should be made to AS 2311 or NZS 7703 for appropriate painting systems.NOTE: Guidance on the use of this Standard is given in Appendix A.

First published in Australia as AS 2312-1980.
Second edition 1984.
Jointly revised and designated as Joint Standard AS/NZS 2312:1994.