1、SSPC-SP COM July 15, 2016 Editorial Revision March 15, 2017 1 SSPC: The Society for Protective Coatings SURFACE PREPARATION COMMENTARY for Metal Substrates 1. Introduction This Surface Preparation Commentary (SP COM) is intended to be an aid for the coating specifier in selecting methods, materials,
2、 and standards for specifying the proper surface preparation for steel, and other metals (not including ductile iron pipe). The use of these standards in a coating specification will give direction to the contractor regarding what is required and give direction to the inspector on verifying complian
3、ce to the specification. The SSPC standards, summarized in Table 1A, represent a broad consensus of users, suppliers, and public interest groups. Details of the methods used to verify many of the properties discussed in this SP COM are described in SSPC publication 03-14, “The Inspection of Coatings
4、 and Linings, A Handbook of Basic Practice for Inspectors, Owners, and Specifiers, 2nd Ed.” Table 1B includes similar standards published by the International Organization for Standardization (ISO) (1) . It should be noted that that while the ISO and SSPC standards are similar and commonly deemed eq
5、uivalent, they are not identical. Tables 3A, 3B, and 3C provide a comparison of the ISO and SSPC standards. 2. Contents 1. Introduction 2. Contents 3. Importance of Surface Preparation 4. Surface Conditions 4.1 New Construction 4.2 Maintenance 4.3 Surface Contaminants 4.4 Surface Defects 4.5 Post-Cl
6、eaning Conditions 5. Tools for Specifying Surface Preparation 5.1 Written Standards 5.2 Reference Photographs 5.3 Job Reference Standards 6. Summary of SSPC Surface Preparation Standards 6.1 SSPC-SP 1, “Solvent Cleaning” 6.2 SSPC-SP 2, “Hand Tool Cleaning” 6.3 SSPC-SP 3, “Power Tool Cleaning” (1) In
7、ternational Organization for Standardization (ISO), Case Postale 56, Geneva CH-1211, Switzerland. In the United States, ISO standards may be obtained from the American National Standards Institute (ANSI) at 6.4 SSPC-SP 4, “Flame Cleaning of New Steel” (discontinued without replacement) 6.5 SSPC-SP 5
8、/NACE No. 1, “White Metal Blast Cleaning” 6.6 SSPC-SP 5 (WAB)/NACE WAB-1, “White Metal Wet Abrasive Blast Cleaning” 6.7 SSPC-SP 6/NACE No. 3, “Commercial Blast Cleaning” 6.8 SSPC-SP 6 (WAB)/NACE WAB-3, “Commercial Wet Abrasive Blast Cleaning” 6.9 SSPC-SP 7/NACE No. 4, “Brush-Off Blast Cleaning” 6.10
9、 SSPC-SP 7 (WAB)/NACE WAB-4, “Brush-Off Wet Abrasive Blast Cleaning 6.11 SSPC-SP 8, “Pickling” 6.12 SSPC-SP 9, “Weathering Followed by Blast Cleaning” (discontinued without replacement) 6.13 SSPC-SP 10/NACE No. 2, “Near-White Metal Blast Cleaning” 6.14 SSPC-SP 10 (WAB)/NACE WAB-2, “Near-White Metal
10、Wet Abrasive Blast Cleaning” 6.15 SSPC-SP 11, “Power Tool Cleaning to Bare Metal” 6.16 SSPC-SP 12/NACE No. 5, “Surface Preparation and Cleaning of Metals by Waterjetting Prior to Coating” (discontinued, see 6.17, 6.18, 6.19 and 6.20) 6.17 SSPC-SP 14/NACE No. 8, “Industrial Blast Cleaning” 6.18 SSPC-
11、SP 14 (WAB)/NACE-WAB 8, “Industrial Wet Abrasive Blast Cleaning” 6.19 SSPC-SP 15, “Commercial Grade Power Tool Cleaning” 6.20 SSPC-SP 16, “Brush-Off Blast Cleaning of Coated and Uncoated Galvanized Steel, Stainless Steels, and Non-Ferrous Metals” 6.21 SSPC-SP WJ-1/NACE WJ-1, “Clean to Bare Substrate
12、” 6.22 SSPC-SP WJ-2/NACE WJ-2, “Very Thorough Cleaning” 6.23 SSPC-SP WJ-3/NACE WJ-3, “Thorough Cleaning” 6.24 SSPC-SP WJ-4/NACE WJ-4, “Light Cleaning” 7. Selection of Abrasives, Blast Cleaning Parameters, and Equipment 7.1 Abrasive Characteristics 7.2 Considerations Affecting Surface Profile 7.3 Par
13、ameters That Affect Productivity 7.4 Abrasive Types 7.5 Blast EquipmentSSPC-SP COM July 15, 2016 Editorial Revision March 15, 2017 2 8. Summary of SSPC Abrasive Standards 8.1 SSPC-AB 1, “Mineral and Slag Abrasives” 8.2 SSPC-AB 2, “Cleanliness of Recycled Ferrous Metallic Abrasives” 8.3 SSPC-AB 3, “F
14、errous Metallic Abrasive” 8.4 SSPC-AB 4, “Recyclable Encapsulated Abrasives” 9. Wet Abrasive Blast and Waterjet Cleaning Methods 9.1 Water Cleaning and Waterjet Cleaning (Without Abrasive) 9.2 Wet Abrasive Blast Cleaning 9.3 Corrosion Inhibitors and Salt Removers 10. Other Cleaning Methods 10.1 Chem
15、ical Stripping 10.2 Sodium Bicarbonate (Baking Soda) Blast Cleaning 10.3 Pliant Media Blasting (Sponge Jetting) 10.4 Carbon Dioxide (Dry Ice) Blasting 10.5 Electrochemical Stripping 10.6 Laser Stripping 11. Film Thickness 12. Consensus Reference Photographs 12.1 SSPC-VIS 1, “Guide and Reference Phot
16、ographs for Steel Surfaces Prepared by Dry Abrasive Blast Cleaning” 12.2 SSPC-VIS 2, “Standard Method of Evaluating Degree of Rusting on Painted Steel Surfaces” 12.3 SSPC-VIS 3, “Guide and Reference Photographs for Steel Surfaces Prepared by Hand and Power Tool Cleaning” 12.4 SSPC-VIS 4/NACE VIS 7,
17、“Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting” 12.5 SSPC-VIS 5/NACE VIS 9, “Guide and Reference Photographs for Steel Surfaces Prepared by Wet Abrasive Blast Cleaning” 12.6 ISO Pictorial Standards 12.7 Other Photographic Standards 13. Other SSPC and Joint SSPC/NACE Sur
18、face Preparation Guides and Reports 13.1 SSPC-TR 1/NACE 6G194, “Joint Technology Report on Thermal Precleaning” 13.2 SSPC-TR 2/NACE 6G198, “Joint Technical Report on Wet Abrasive Blast Cleaning” 13.3 SSPC-Guide 15, “Field Methods for Retrieval and Analysis of Soluble Salts on Steel and Other Nonporo
19、us Substrates” 13.4 SSPC-TU 6, “Chemical Stripping of Organic Coatings from Steel Structures” 14. Non-SSPC Cleaning Standards 15. Surface Preparation of Other Metallic Surfaces 15.1 SSPC-SP 16, “Brush-Off Blast Cleaning of Coated and Uncoated Galvanized Steel, Stainless Steels, and Non-Ferrous Metal
20、s” 15.2 Aluminum 15.3 Stainless Steel 15.4 Copper Alloys 3. Importance of Surface Preparation Often, the surface preparation of steel for coating requires a three-step process: 1) initial pre-cleaning to remove deposits of grease, oil, dirt, and other surface contaminants; 2) cleaning with hand/powe
21、r tools, pressurized water, chemicals, or abrasive blasting; 3) creation or verification of the specified anchor pattern profile. The life of a coating depends as much on the degree and quality of surface preparation as on the selected coating system, because most coating failures can be attributed
22、to inadequate surface preparation or lack of coating adhesion. Surface preparation, therefore, should receive thorough consideration. The primary functions of surface preparation are: to remove surface contaminants that can induce premature coating failure to provide a clean surface with adequate pr
23、ofile for good coating adhesion Where conventional abrasive blast cleaning is not allowed or is impractical, alternative abrasives or methods of cleaning the surface must be employed. Chemical stripping will remove coating and is relatively easy to contain. Hence, chemical stripping may be used arou
24、nd sensitive machinery or in densely populated areas. (Refer to SSPC-TU 6, “Chemical Stripping of Organic Coatings from Steel Structures.”) Alternative abrasives such as sodium bicarbonate (baking soda) or dry ice (CO 2 ) can sometimes be used in places where conventional abrasives cannot be used. A
25、 class of abrasives has been developed that surrounds each abrasive particle with an open-cell sponge matrix. The sponge contains the abrasive and facilitates cleanup and recycling. When control of dust emissions is critical, wet blast cleaning methods are often employed. Wet blast cleaning methods
26、may involve water alone, abrasive injected into the water stream, water injected into an abrasive air stream, or a water curtain surrounding an air/abrasive stream. Power tools with vacuum shrouds have also been proven effective in controlling dust emissions, particularly in removing lead-containing
27、 coatings. It is important to note that surface preparation methods used to control dust may not necessarily eliminate any hazards associated with disturbance of hazardous materials such as lead. In applications where the presence of soluble salts on the steel surface creates a serious problem, such
28、 as tank linings, it could be beneficial to incorporate water into the cleaning process. The use of water alone (without abrasive media) at various pressures is a technique for surface preparation that will remove coatings and contaminants without altering the existing surface profile.SSPC-SP COM Ju
29、ly 15, 2016 Editorial Revision March 15, 2017 3 TABLE 1A SUMMARY OF CURRENT SSPC ABRASIVE AND SURFACE PREPARATION STANDARDS SSPC STANDARD DESCRIPTION SSPC-AB 1 Mineral and Slag Abrasives Definition of requirements for selecting and evaluating mineral and slag abrasives used for blast cleaning SSPC-A
30、B 2 Cleanliness of Recycled Ferrous Metallic Abrasive Cleanliness requirements for a recycled work mix and a description of the test procedures. SSPC-AB 3 Ferrous Metallic Abrasives Requirements for chemical and physical properties of iron and steel abrasives. SSPC-AB 4 Recyclable Encapsulated Abras
31、ive Media Requirements for physical properties and cleanliness of abrasive media encapsulated in a compressible non-uniform cellular matrix. SSPC-PA 17 Conformance to Profile/Surface Roughness/ Peak Count Requirements A procedure suitable for shop or field use for determining compliance with specifi
32、ed profile ranges on a steel substrate. SSPC-SP 1 Solvent Cleaning Removal of oil, grease, dirt, soil, salts, and contaminants by cleaning with solvent, vapor, alkali, emulsion, or steam. SSPC-SP 2 Hand Tool Cleaning Removal of loose rust, loose mill scale, and loose paint to degree specified, by ha
33、nd chipping, scraping, sanding, and wire brushing. SSPC-SP 3 Power Tool Cleaning Removal of loose rust, loose mill scale, and loose paint to degree specified, by power tool chipping, descaling, sanding, wire brushing or wire impact tools, and grinding. SSPC-SP 5/NACE No. 1 White Metal Blast Cleaning
34、 Removal of all visible rust, mill scale, paint, and foreign matter by blast cleaning by wheel or nozzle (dry or wet) using sand, grit or shot. SSPC-SP 5 (WAB)/ NACE WAB-1* White Metal Wet Abrasive Blast Cleaning Same level of cleanliness as SSPC-SP 5/NACE No. 1, but achieved by wet abrasive blast c
35、leaning. Level of flash rust permissible immediately prior to coating application must be specified. SSPC-SP 6/NACE No. 3 Commercial Blast Cleaning Removal of all visible rust, mill scale, paint, and foreign matter by blast cleaning. Staining is permitted on no more than 33% of each 9 in 2area. SSPC
36、-SP 6 (WAB)/ NACE WAB-3 Commercial Wet Abrasive Blast Cleaning Same level of cleanliness as SSPC-SP 6/NACE No. 3, but achieved by wet abrasive blast cleaning. Level of flash rust permissible immediately prior to coating application must be specified. SSPC-SP 7/NACE No. 4 Brush-Off Blast Cleaning Bla
37、st cleaning of all except tightly adhering residues of mill scale, rust, and coatings, while uniformly roughening the surface. SSPC-SP 7 (WAB)/ NACE WAB-4 Industrial Wet Abrasive Blast Cleaning Same level of cleanliness as SSPC-SP 7/NACE No. 4, but achieved by wet abrasive blast cleaning. Level of f
38、lash rust permissible immediately prior to coating application must be specified. SSPC-SP 8 Pickling Complete removal of rust and mill scale by acid pickling, duplex pickling, or electrolytic pickling. SSPC-SP 10/NACE No. 2 Near-White Blast Cleaning Removal of all visible rust, mill scale, paint, an
39、d foreign matter by blast cleaning. Staining is permitted on no more than 5% of each 9 in 2area of the cleaned surface. SSPC-SP 10 (WAB)/NACE WAB-2 Near White Metal Wet Abrasive Blast Cleaning Same level of cleanliness as SSPC-SP 10/NACE No. 2, but achieved by wet abrasive blast cleaning. Level of f
40、lash rust permissible immediately prior to coating application must be specified. SSPC-SP 11 Power Tool Cleaning to Bare Metal Complete removal of all rust, scale, and paint by power tools, with resultant minimum surface profile of 25 m (1 mil). SSPC-SP 14/NACE No. 8 Industrial Blast Cleaning Betwee
41、n SP 7 (brush-off) and SP 6 (commercial). The intent is to remove as much coating as possible, but tightly adherent rust, mill scale, and coating can remain on 10 percent of each 9 in 2area of the cleaned surface. SSPC-SP 14 (WAB)/NACE WAB-8 Industrial Wet Abrasive Blast Cleaning Same level of clean
42、liness as SSPC-SP 14/NACE No. 8, but achieved by wet abrasive blast cleaning. Level of flash rust permissible immediately prior to coating application must be specified. SSPC-SP 15 Commercial Grade Power Tool Cleaning Between SP 3 and SP 11. Removes all rust and paint but allows for random staining
43、on up to 33% of each 9 in 2 area of surface; requires a minimum 25 m (1 mil) profile. SSPC-SP 16 Brush-Off Blast Cleaning of Coated and Uncoated Galvanized Steel, Stainless Steels, and Non-Ferrous Metals Requirements for removing loose contaminants and coating from coated and uncoated galvanized ste
44、el, stainless steels, and non-ferrous metals. Requires a minimum 19 m (0.75 mil) profile on bare metal substrate. SSPC-SP COM July 15, 2016 Editorial Revision March 15, 2017 4 The remainder of this page is intentionally left blank. SSPC-SP WJ-1/NACE WJ-1 Waterjet Cleaning of MetalsClean to Bare Subs
45、trate Cleanest waterjetting level, requires the cleaned metal to be free of all visible oil, grease, dirt, rust and other corrosion products, previous coatings, mill scale, and foreign matter. SSPC-SP WJ-2/NACE WJ-2 Waterjet Cleaning of MetalsVery Thorough Cleaning Requires the cleaned metal surface
46、 to be free of all visible oil, grease, dirt, rust, and other corrosion products except for randomly dispersed stains of rust and other corrosion products, tightly adherent thin coatings, and other tightly adherent foreign matter over no more than 5% of each 9 in 2area of the cleaned surface. SSPC-S
47、P WJ-2/NACE WJ-3 Waterjet Cleaning of MetalsThrough Cleaning Requires removal of all visible contaminants as in WJ-2 above. Randomly dispersed staining as described in WJ-2 is limited to no more than 33% of each 9 in 2area of the cleaned surface. SSPC-SP WJ-4/NACE WJ-4 Waterjet Cleaning of MetalsLig
48、ht Cleaning Requires removal of all visible oil, grease, dirt, dust, loose mill scale, loose rust and other corrosion products, and loose coating. Any residual material shall be tightly adhered to the metal substrate.SSPC-SP COM July 15, 2016 Editorial Revision March 15, 2017 5 TABLE 1B SUMMARY OF I
49、NTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) SURFACE PREPARATION STANDARDS ISO Standard 8501-1 Description Sa 1 Light blast cleaning Free of oil, grease and dirt and poorly adhering mill scale, rust, paint and foreign matter Sa 2 Thorough blast cleaning Free of oil, grease and dirt and most of the mill scale, rust paint and foreign has been removed Sa 2 Very thorough blast cleaning Free of oil, grease and dirt and from mill scale, rust and paint. Remaining traces of contamination will only be slight stains. Sa 3 Blast cleaning to visually clean steel Free of oil, grease, di
