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68 9 QUALIFICATIONS 9.1 Equipment 9.1.1 Qualification Each type and source of thermal spray equipment should be qualified prior to use. The equipment should conform to the following requirements related to uniformity of operation, coating appearance, and coating adhesion. Equipment should be qualified using the type and size of wire to be used on the job. The operating parameters should be those selected by the contractor for use on the job. Equipment manufacturers may also qualify their equipment for use with specific feedstocks and operating parameters. Such qualified equipment should be accepted as prequalified, assuming the contractor proposes to operate the equipment in the same manner used for the qualification tests. 9.1.2 Wire-Flame Spray Equipment 9.1.2.1 Gases. Flame-spraying equipment shall permit spraying with the combustible gases, atomizing gas (if any), and carrier gas (if any) for which it was designed. 9.1.2.2 Oxygen and fuel gas flow rates. Under conditions of continuous use, the actual oxygen and fuel gas flow rates and pressures should remain nearly constant and should not deviate from the set values by more than 5 percent during a 15-minute period. 9.1.2.3 Atomization air pressure. Compressed air should be free of oil and water. Under conditions of continuous use, the actual atomization air pressure and flow volume should remain nearly constant and should not deviate from the set value by more than 5 percent during a 15-minute period. 9.1.2.4 Wire feed rate. It shall be possible to adjust the spraying material feed rate. Under conditions of continuous use, the actual wire feed rate should remain nearly constant and should not deviate from the set value by more than 5 percent during a 15-minute period. The set values shall be constant and reproducible; preconditions of this are adequate and constant gas pressures, atomizing air pressures, and supply of electrical power as appropriate. With regard to continuous operation, the equipment should not sputter, pop, or stop operating when operated continuously for 15 minutes. 9.1.2.5 Control unit and monitoring. It shall be possible to monitor and control, read clearly and correct, by means of instruments, any deviations from the set values of atomizing gas pressure and gas volume flow rate during the spraying process. These values shall be recorded during acceptance inspection. The limits of error of the measuring instruments shall not exceed 5 percent for all set values and shall correspond to at least Class 2.5 instruments. The reproducibility of the setting shall be proved.

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69 9.1.2.6 Nozzle system. The nozzle system shall be considered acceptable if, after 20 minutes of spraying 8515 wt% zinc/aluminum wire at the maximum spray rate, there are no degrading deposits of spraying material on or in the nozzle. Nozzles shall be acceptable if, after 20 minutes of spraying nozzle-compatible materials at the maximum spray rate, there are no degrading deposits of spraying material on or in the nozzle. 9.1.3 Wire-Arc Spray Equipment 9.1.3.1 Power. Under conditions of continuous use, the actual current output should remain nearly constant and should not deviate from the set value by more than 5 percent during a 15-minute period. 9.1.3.2 Voltage. Under conditions of continuous use, the actual voltage should remain nearly constant and should not deviate from the set value by more than 5 percent during a 15-minute period. 9.1.3.3 Wire feed mechanism. The wire feed mechanism should be designed for automatic alignment. Under conditions of continuous use, the actual wire feed rate should remain nearly constant and should not deviate from the set value by more than 5 percent during a 15-minute period. 9.1.3.4 Atomization air pressure. Under conditions of continuous use, the actual atomization air pressure and flow volume should remain nearly constant and should not deviate from the set value by more than 5 percent during a 15-minute period. 9.1.3.5 Continuous operation. When operated continuously for 15 minutes, the equipment should not sputter, pop, or stop operating. 9.1.3.6 On/off operation. The equipment should be capable of continuous start and stop operation for a minimum of 15 cycles consisting of 10 seconds on and 5 seconds off without fusing, sputtering, or deposition of nodules. 9.1.3.7 Nozzle system (contact tubes and air nozzle). The nozzle system shall permit a constant arc to be maintained and provide atomization without causing a buildup of deposits that will degrade gun operation. The nozzle system shall be acceptable if, after 20 minutes of spraying 8515 wt% zinc/aluminum wire at the maximum spray rate, there are no degrading deposits of spraying material on or in the nozzle. 9.1.3.8 Coating appearance. The applied coating should be uniform and free of blisters, cracks, loosely adherent particles, nodules, and powdery deposits. 9.1.3.9 Coating adhesion. A 12- 12- 0.5-in. (30- 30- 1.25-cm) flat steel plate should be cleaned and prepared in accordance with SSPC-SP-1 and SSPC-SP-5. No. 36 aluminum oxide grit should be used to produce an angular blast profile of 0.003 0.0002 in. (75 5m). The blast profile should be measured and recorded using replica tape in accordance with ASTM D4417. The coating of 8515 wt% zinc/aluminum alloy (0.016 0.002 in. [400 50 m]), zinc (0.016 0.002 in. [400 50 m]), or aluminum (0.010 0.002 in. [250 50 m]) should be applied in not less than two half-lapped passes applied at right angles to each other.

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70 The adhesion should be tested in accordance with ASTM D4541 using a self-aligning Type IV adhesion tester as described in this guide. Scarified aluminum pull stubs should be attached to the TSMC using a two-component epoxy adhesive. The adhesive strength of the coating should be measured and recorded at five randomly selected locations. The average adhesion should not be less than 1,000 psi (6,895 kPa), 1,600 psi (11,032 kPa), and 750 psi (5,171 kPa) for 8515 wt% zinc/aluminum alloy, aluminum, and zinc coatings, respectively. If the test fails, it should be repeated using a new test plate. If the adhesion fails on the second plate, the equipment should be deemed unacceptable. 9.1.4 Retests If the values obtained during acceptance inspection of a thermal spraying system are altered by modification or repair work, retesting of the properties affected shall be carried out. Retests shall be carried out in the same way as the initial tests described in this standard. 9.2 Applicator 9.2.1 General Requirements 9.2.1.1 Terminology. When the term "certified thermal sprayer" is used, it should denote "thermal spray operator or technician." 9.2.1.2 Required skills. A thermal sprayer must have adequate instruction and training and shop and field experience to safely and proficiently apply thermal spray coatings of aluminum, zinc, and their alloys on steel. The thermal sprayer should demonstrate the ability to set up, operate (including field troubleshooting and repair), and secure thermal spray equipment. The sprayer should be knowledgeable in cleaning and preparing the steel. The sprayer should be skilled in spraying the TSMCs using the intended thermal spray equipment in accordance with the equipment manufacturer's instructions/technical manual and the purchaser's contract specifications. The thermal sprayer should be able to recognize proper masking and surface preparation. The thermal sprayer must be able to recognize unsatisfactory surface preparation and call for corrective action, or stop the job until deficiencies are corrected. 9.2.1.3 Standards and references for certification. The thermal sprayer knowledge and skill requirements do not supersede an employer's or contractor's ability to continue to certify thermal sprayers in accordance with the following other standards and references: ASTM D4228, "Practice for Qualification of Coating Applicators for Application of Coatings to Steel Surfaces." MIL-STD-1687A (SH), "Thermal Spray Processes for Naval Ship Machinery Applications," 2/11/87. Various original equipment manufacturers (OEMs) or after-market repair, or both. Thermal spray process and spray parameter specifications from the OEM or after-market repair facility. Material safety data sheets (MSDSs) for abrasive blasting and thermal spray feedstock materials. EN 657, Thermal spraying--Terminology, classification, April 1994.

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71 9.2.1.4 Basic skills. Thermal sprayers must have basic knowledge and skills in safe assembly, setting up, operating, and closing down procedures for equipment; personal protection; fire hazards; dust explosions; electrical hazards; flash backs; leak detection; UV radiation; and noise. 9.2.2 Demonstration of Applicator Skills 9.2.2.1 Equipment setup and operation. The TSMC applicator should be qualified to SSPC-QP-1 in regards to field application of TSMC work on complex structures or as otherwise specified by the purchasing contract. The thermal spray operator must have normal or corrected 20/20 vision. The qualified applicator should be able to demonstrate a working knowledge of the application equipment to be used on the job by proper setup and operation of the equipment. The applicator should prepare a 12- 12- 0.5-in. (30- 30- 1.25-cm) flat steel plate cleaned in accordance with SSPC-SP-1 and SSPC-SP-5. Aluminum oxide or steel grit should be used to produce an angular blast profile of 3.0 0.2 mils (76 5 m). The blast profile should be measured and recorded using replica tape in accordance with ASTM D4417. The applicator should apply the coating of 8515 wt% zinc/aluminum alloy (16 2 mils [400 50 m]), zinc (16 2 mils [406 50 m]), or aluminum (10 2 mils [250 50 m]) using the proper spray technique. 9.2.2.2 Coating appearance. The qualified applicator will have applied a coating that is uniform and free of blisters, cracks, loosely adherent particles, nodules, or powdery deposits. 9.2.2.3 Coating adhesion. The qualified applicator should be able to apply a firmly adherent coating that meets the adhesion requirements of the contract. The TSMC adhesion should be tested in accordance with ASTM D4541 using a self-aligning Type IV adhesion tester as described in Annex A4 of the method. Scarified aluminum pull stubs should be attached to the TSMC using a two-component epoxy adhesive. The adhesive strength of the coating should be measured and recorded at five randomly selected locations. The average adhesion should not be less than 1,000 psi (6,895 kPa), 1,600 psi (11,032 kPa), and 750 psi (5,171 kPa) for 8515 wt% zinc/aluminum alloy, aluminum, and zinc coatings, respectively. 9.3 Inspector 9.3.1 Description of Inspector's Role The TSMC inspector is a person who is knowledgeable in the concepts and principles of this guide and skilled in observing and measuring conformance to them. Ideally, a third disinterested party will employ the inspector. Specific qualifications of an inspector are listed below. 9.3.1.1 Vision requirements. The inspector must have normal or corrected 20/20 vision. 9.3.1.2 ASTM D3276. An inspector must have the knowledge and ability to meet the guidelines specified in ASTM D3276, "Standard Guide for Painting Inspectors (Metal Substrates)."

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72 9.3.1.3 Training program. Completion of a formal training program, such as the one offered by NACE International, and certification as a NACE International Certified Coating Inspector are recommended. 9.3.1.4 Basic knowledge requirements. The inspector should meet the basic knowledge requirements of a qualified thermal spray operator with respect to the following: The inspector should be qualified to SSPC-QP-1 in regards to field application of TSMC work on complex structures or as otherwise specified by the purchasing contract. The inspector should have a working knowledge of the methods of TSMC application, particularly the method to be used at the job site. The inspector should be able to demonstrate a working knowledge of the application equipment to be used on the job by proper setup and operation of the equipment. 9.3.1.5 Observation and evaluation skills. The inspector should be skilled in observing and evaluating conformance of the application process to the contract specifications. 9.3.1.6 Job reference standard. The inspector should be skilled in setting up a job reference standard as described in Section 8. 9.3.1.7 Knowledge and skills in use of inspection equipment. The inspector should be knowledgeable and skilled in the use of inspection equipment to measure and validate the coating applicator's conformance to the purchasing contract. Specifically (further details are provided in Section 8 and in referenced test methods), the inspector should be Skilled in measuring surface temperature, dew point, and ambient air temperature and in calculating the dew point. Specific skills include the use of a surface temperature gauge, sling psychrometer, psychrometric charts, and digital measuring equipment. Skilled in the use of water break, UV light, solvent evaporation, and heat tests to detect grease and oil. Skilled in the use of conductivity, commercially available colorimetric kits, and titration kits for the measurement of soluble salts and skilled in the use of a Bresle kit for soluble salt measurement. Knowledgeable about SSPC-AB-2, "Specification for Cleanliness of Recycled Ferrous Metallic Abrasives," and ASTM D4940, "Test Method for Conductimetric Analysis of Water Soluble Ionic Contamination of Blasting Abrasives," for the detection of salt in abrasives. Skilled in the detection of oil in abrasives. Knowledgeable about ASTM D4285, "Method for Indicating Water or Oil in Compressed Air." Skilled in measuring blast air pressure and nozzle orifice condition. Knowledgeable about SSPC surface preparation standards, specifically SSPC-SP-5 and SSPC-VIS-1. Skilled in testing surface profile using ASTM D4417, Method C. Skilled in measuring coating thickness per SSPC-PA-2 using a Type 2 gauge, in accordance with ASTM D4138, "Test Methods for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive Means."

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73 Skilled in conducting adhesion tests, including the bend test, tensile adhesion test (ASTM D4541, "Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers," using a self-aligning Type IV tester, described in Annex A4 of ASTM D4541), and cut test as described in Section 8. Knowledgeable about the ASTM test methods available to quantify coating defects. 9.3.1.8 Communications and conflict-resolution skills. The inspector should be skilled in communications and conflict resolution so that when application errors are found, they may be corrected without significant disruption to the schedule. 9.3.1.9 Reports. The inspector should submit timely oral and written reports to the purchaser.