SSPC SP 11-2012 Power-Tool Cleaning to Bare Metal.pdf

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1、SSPC-SP 11July 19, 2012Editorial Revisions November 11, 20131SSPC: The Society for Protective CoatingsSurface Preparation Standard No. 11Power-Tool Cleaning to Bare Metal2.5 Reference photographs of power-tool cleaned surfaces found in SSPC-VIS 3 are often used to supplement the written definition.

2、In any dispute, the written definition set forth in this standard shall take precedence over reference photographs. Additional information on reference photographs is in Note 8.3.3. Referenced Standards 3.1 The latest issue, revision, or amendment of the refer-enced standards in effect on the date o

3、f invitation to bid shall govern unless otherwise specified. Standards marked with an asterisk (*) are referenced only in the Notes, which are not requirements of this standard.3.2 If there is a conflict between the requirements of any of the cited reference standards and this standard, the require-

4、ments of this standard shall prevail.3.3 SSPC STANDARDS:* PA 2 Procedure for Determining Conformance to Dry Coating Thickness RequirementsSP 1 Solvent CleaningSP 3 Power-Tool Cleaning* SP 5/NACE No. 1 White Metal Blast Cleaning SP 15 Commercial Grade Power-Tool cleaningVIS 3 Guide and Reference Phot

5、ographs for Steel Surfaces Prepared by Power- and Hand-Tool Cleaning 3.4 ASTM INTERNATIONAL STANDARDS2:D 4285 Method for Indicating the Presence of Oil or Water in Compressed Air D 4417 Standard Test Methods for Field Measurement of Surface Profile of Blast-Cleaned Steel* D 7127 Standard Test Method

6、 for Measure-ment of Surface Roughness of Abrasive Blast-Cleaned Metal Surfaces Using a Portable Stylus Instrument2 ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at se

7、rviceastm.org. For Annual Book of ASTM Standards volume information, refer to the standards Docu-ment Summary page on the ASTM website.1. Scope 1.1 This standard contains the requirements for power-tool cleaning steel to produce a bare metal power tool cleaned surface having a minimum 25-micrometer

8、(1.0-mil) surface profile.1.2 This standard is suitable where a roughened, clean, bare metal surface as defined in Section 2.1 is required, but where abrasive blasting is not feasible or permissible (see Notes 8.1 and 8.2).1.3 This standard differs from SSPC-SP 3, Power-Tool Cleaning, in that SSPC-S

9、P 3 requires the removal of loosely adherent materials only, and contains no requirement to expose bare metal or to achieve a minimum surface profile.1.4 This standard differs from SSPC-SP 15, Commercial Grade Power-Tool Cleaning, in that SSPC-SP 15 allows stains to remain on the surface.2. Definiti

10、on2.1 A bare metal power tool cleaned surface, when viewed without magnification, shall be free of all visible oil, grease, dust, dirt, mill scale, rust, coating, corrosion products, and other foreign matter, with the exception of trace amounts of coating and corrosion products in the lower portion

11、of pits on pitted substrates (see Notes 8.1 and 8.3).2.2 Acceptable variations in appearance that do not affect surface cleanliness as defined in Section 2.1 include variations caused by type of steel, original surface condition, thickness of the steel, weld metal, mill or fabrication marks, heat tr

12、eating, heat-affected zones, or the texture/features associated with the use of a particular power tool. 2.3 The surface profile shall be a minimum of 25 microm-eters (1.0 mil). The peaks and valleys on the prepared surface shall form a continuous pattern with no smooth, unprofiled areas. 2.4 The pr

13、ofile shall be measured in accordance with ASTM D 4417 Method B unless otherwise specified (see Notes 8.4, 8.5, and 8.6).11 Although ASTM D 4417 and ASTM D 7127 indicate in their titles that they describe methods intended for use on blast-cleaned steel, there is currently no method specifically desi

14、gned for measurement of profile on steel surfaces prepared using power-tools. Visual comparators used for ASTM D 4417 Method A represent surfaces prepared by abrasive blast cleaning and are inappropriate for comparison with power-tool cleaned surfaces. The replica tape used for ASTM D 4417 Method C

15、cannot accurately measure the profile produced by some types of power-tool cleaning media. A test area prepared at the job site can be used to assess the suitability of media and profile measurement method for a project prior to full-scale production.SSPC-SP 11July 19, 2012Editorial Revisions Novemb

16、er 11, 201324. Tools and Methods for Power-Tool Cleaning to Bare Metal 4.1 POWER TOOLS: Any hand-held motorized tool on which the media described in Sections 4.1.1 and 4.1.2 are capable of being mounted in accordance with manufacturers instructions and that will produce a steel surface meeting the r

17、equirements of Sections 2.1 and 2.3 is acceptable (see Notes 8.7.1, 8.7.2, 8.8, and 8.9). Sections 4.1.1 and 4.1.2 describe the two main categories of power tools. It is possible for power tools to alter an existing surface profile. 4.1.1 Grinding Tools: Grinding tools use media containing bonded ab

18、rasive grains to cut through corroded surfaces and include, but are not limited to, discs or wheels as described in Note 8.6.1. 4.1.2 Impact Tools: Impact tools use media that repeat-edly collide with the target surface and include, but are not limited to, various rotary and reciprocating devices as

19、 described in Note 8.6.2. 4.2. The use of several different power tools meeting the requirements of Sections 4.1, 4.1.1 and 4.1.2 is sometimes necessary to achieve a bare metal power-tool cleaned surface meeting the requirements of Sections 2.1 and 2.3 (see Note 8.7 and subsections).4.3 If the procu

20、rement documents require power-tool cleaning to prepare surfaces for subsequent coating, the edges of remaining intact coatings shall, unless otherwise specified, be feathered to improve the appearance of the repaired coating (see Note 8.2).5. Procedures Prior to Power-Tool Cleaning 5.1 Prior to pow

21、er-tool cleaning, visible deposits of oil, grease, or other materials that interfere with coating adhesion shall be removed in accordance with SSPC-SP 1 or other specified methods.5.2 Surface imperfections such as slivers and laminations, sharp edges, weld spatter, or burning slag shall be removed f

22、rom the surface to the extent specified by the procurement documents project specifications (see Note 8.10). 5.3 When air-driven tools are used, cleanliness of the compressed air shall be verified in accordance with the proce-dure described in ASTM D 4285.6. Procedures Following Power-Tool Cleaning

23、and Immediately Prior to Coating6.1 Visible deposits of oil, grease, or other contami-nants shall be removed in accordance with SSPC-SP 1 or as specified. 6.2 Dust and loose residues shall be removed from power-tool cleaned (SSPC-SP 11) surfaces by brushing; blowing off with clean, dry air per Secti

24、on 5.3; vacuum cleaning; or other methods established in the procurement documents (project specification).6.3 After power-tool cleaning, any remaining surface imperfections as described in Section 5.2 (e.g., laminations, sharp edges, weld spatter, burning slag, scabs, slivers) shall be removed to t

25、he extent required by the procurement docu-ments (project specification). Any damage to the surface profile resulting from the removal of surface imperfections shall be corrected to meet the requirements of Section 2.3 (see Note 8.10).6.4 Immediately prior to coating application, the entire surface

26、to be coated shall comply with the requirements of Sections 2.1 and 2.3 (see Notes 8.11 and 8.12).7. Disclaimer7.1 While every precaution is taken to ensure that all information furnished in SSPC standards and specifications is as accurate, complete, and useful as possible, SSPC cannot assume respon

27、sibility nor incur any obligation resulting from the use of any materials, coatings, or methods specified herein, or of the specification or standard itself.7.2 This standard does not attempt to address prob-lems concerning safety associated with its use. The user of this standard, as well as the us

28、er of all products or practices described herein, is responsible for instituting appropriate health and safety practices and for ensuring compliance with all applicable governmental regulations.8. NotesNotes are not requirements of this standard.8.1 FUNCTION: The type of power-tool surface prepa-rat

29、ion described in this standard removes tightly adherent material, producing a surface that is free from rust, mill scale, and old coatings. The surface must also have a minimum 25-micrometer (1.0 mil) surface profile. Power-Tool Cleaning to Bare Metal produces a greater degree of cleaning than SSPC-

30、SP 3, which does not remove adherent material, and SSPC-SP 15, which allows visible stains on 33% of each unit area. Power-Tool Cleaning to Bare Metal may be considered for coatings that require a very clean surface. This standard is suitable where a roughened, cleaned surface is required, but where

31、 abrasive blasting is not feasible or permissible. The surfaces prepared according to this stan-dard should not be compared to surfaces cleaned by abrasive blast cleaning. Although this method produces surfaces that resemble SSPC-SP 5 (White Metal Blast Cleaning), with the exception of material allo

32、wed in pits, power-tool cleaned surfaces are not necessarily equivalent to surfaces produced by abrasive blast cleaning. The contracting parties should agree on the appropriateness of the finished surface to accept the specified coating system. Selection of power tools and SSPC-SP 11July 19, 2012Edi

33、torial Revisions November 11, 20133cleaning media should be based on (1) the condition of the surface prior to surface preparation; (2) the extent of cleaning that is required; and (3) the surface profile required.The SSPC Surface Preparation Commentary (SSPC-SP COM) provides additional information

34、on subjects related to power-tool cleaning. The recommendations contained in SSPC-SP COM are believed to represent good practice, but are not to be considered requirements of this standard.8.2 MAINTENANCE AND REPAIR PAINTING: When this standard is used in maintenance painting, specific instruc-tions

35、 should be given on the extent of surface to be power-tool cleaned, including any additional requirements for retaining old paint, removing unsound paint, feathering and spot cleaning. 8.3 VISUAL GUIDES AND COMPARATORS: Note that the use of visual guides or comparators in conjunction with this stand

36、ard is required only when they are specified in the procurement documents (project specification) covering the work. It is recommended, however, that the use of visual guides or comparators be made mandatory in the procurement documents. SSPC-VIS 3 provides a suitable comparative visual guide for SS

37、PC-SP 3, SSPC-SP 11, and SSPC-SP 15. However, visual comparators for blast-cleaned steel (e.g., SSPC-VIS 1) are not suitable for assessing power-tool cleaned surfaces. Because power-tool cleaning is time- and labor-intensive, it is advisable to prepare a test area of 1 x 1 sq meter (3 x 3 sq. ft.) f

38、or large areas or 30 x 30 cm (12 x 12 inch) for spot cleaning to an acceptable level agreed upon by the contracting parties, and cover it with a clear lacquer to save it as a stan-dard during the power-tool cleaning operation. A 30 x 30 cm (12 x 12 inch) steel test plate can also be power-tool clean

39、ed to an acceptable level and sealed to serve as a project standard. Alternatively, such a field standard could be protected with a volatile corrosion inhibitor, tablet, or impregnated paper, with or without a desiccant, and kept in a sealed plastic bag to permit examination of the surface profile.8

40、.4 PROFILE: The profile created by any cleaning media depends on many factors, including the composition and hard-ness of the steel, the presence and depth of any pre-existing profile, and the hardness and thickness of any existing coating materials.The ability of various media to produce a profile

41、or main-tain an existing profile depends upon physical characteristics such as hardness, angularity or sharpness, size and mass; spacing; speed (velocity) of impact on the steel; and ability to fracture the coating material and alter the steel surface. The media indicated in Section 4.1.1 are capabl

42、e of producing a profile of 12.5 micrometers (0.5 mil) on mild (struc-tural) steel, while the media in Section 4.1.2 are capable of producing a profile of 25 micrometers (1.0 mil) and greater on mild steel. The same media may not be capable of producing the same profile depth on other steels, e.g.,

43、weathering steel, stainless steel, welds, et al. These capabilities are possible when the tools are used by an experienced operator.Power tools are also capable of reducing existing deeper profiles by partial removal of the tops of the existing profiles, especially by grinding, sanding, and the use

44、of rotary flaps. In cases of excessive pressure or dwell period at a specific location, the power tools can cause sharp edges and cuts in the steel. Rotary power tools can cause a burnishing of profile previously imparted to steel or of the existing profile, thereby reducing that profile. Impact pow

45、er tools can cause burrs and gouges.It is important to determine prior to the start of production if the power tools to be used can create a profile that meets the requirement of the project specification or the manufac-turers requirement for the specified coating. Concerns about the suitability of

46、a tool to achieve these requirements should be discussed in advance with the tool manufacturers technical representative.8.5 FILM THICKNESS: It is essential that ample coating be applied after power-tool cleaning to adequately cover the peaks of the surface profile. The dry film thickness above the

47、peaks of the profile should equal the thickness needed for the desired protection. If the dry film thickness over the peaks is inadequate according to contract documents or manufactur-ers specifications, premature rust-through or failure will occur. The procedures in SSPC-PA 2 should be used to ensu

48、re that coating thickness is properly measured.8.6 SUITABLE TOOLS AND MEDIA: The tools/media in the text of this standard are intended solely to guide the user to typical types of equipment and media that are available to meet the standard. The tools/media cited in this document do not include all o

49、f the tools, devices, or products available, nor does their mention constitute an endorsement by SSPC. The presence of hazardous material in the coatings, cleaning media, or in the work area itself, can place restrictions on the methods of cleaning permitted.8.6.1 Grinding tools/media: Any rotary or reciprocating tool that uses bonded abrasives as the cutting media for gener-ating surfaces meeting requirements of Sections 2.1, 2.2, and 2.3 These include, but are not limited to, reciprocating sanders, orbital sanders, or any grinding device, whether right angle or straight shaft, that