and paints that can be harmed by exposure to cold weather shall be stored
in ventilated, heated shelters. All sealers and paints shall be stored
under cover from the elements and in locations free from sparks and flames.
1.7
JOB REFERENCE STANDARD
A thermal spray Job Reference Standard (JRS) shall be prepared. The JRS is
used at the initiation of the contract to qualify the surface preparation,
thermal spray application, and sealing processes. The JRS also serves as a
standard of quality in case of dispute. The JRS shall be prepared at the
jobsite prior to the onset of production work. To prepare the JRS a steel
plate of the same alloy as the surfaces to be metallized measuring 600 x
600 x 10 mm 2 feet x 2 feet x 3/8 inch shall be solvent and abrasive blast
cleaned in accordance with the requirements of the contract. The abrasive
blast media and equipment shall be those that will be used on the job.
One-fourth of the JRS plate shall be masked with sheet metal and the
thermal spray coating applied to the unmasked portion of the plate. The
thermal spray coating shall be applied using the same equipment, approved
wire, and spray parameters to be used on the job. The gun shall be
operated in a manner substantially the same as will be used on the job. The
approximate traverse speed and standoff distance during spraying shall be
measured and recorded. Once the JRS is qualified, the operating parameters
shall not be altered by the contractor, except as necessitated by the
requirements of the job. Two-thirds of the thermal spray coated portion of
the JRS shall be sealed in accordance with the requirements of the
contract. One-half of the sealed area shall be painted in accordance with
the contract if applicable. The sealer and paint shall be applied using
the same paint spray equipment that will be used for production. The
prepared JRS shall be preserved and protected in such a manner that it
remains dry and free of contaminants for the duration of the contract. The
surface cleanliness, blast profile shape and depth, thermal spray
appearance, thickness, and adhesion, and sealer and paint thicknesses shall
be determined by the Coating Inspector in accordance with the contract
requirements and recorded.
1.8
QUALIFICATIONS
1.8.1
Contractor Qualifications and Experience
The Contractor shall have a minimum of two years of documented experience
in the field of thermal spray and shall have performed at least one similar
project in the past.
1.8.2
Arc Spray Equipment Qualification
Each type and model of arc spray equipment to be used on the job shall be
qualified in accordance with the requirements of this subpart. Under
conditions of continuous use, the equipment shall be capable of keeping the
actual current output, voltage, wire feed rate, atomization air pressure,
and flow volume at set values and shall not deviate from them by more than
5 percent during a 15 minute period. The wire feed mechanism shall be
designed for automatic alignment. When operated continuously for 15
minutes the equipment shall not sputter, pop, or stop operating. The
equipment shall be capable of continuous start and stop operation for a
minimum of fifteen cycles consisting of 10 seconds on and 5 seconds off,
without fusing, sputtering or deposition of nodules. The applied coating
shall be uniform and free of blisters, cracks, loosely adherent particles,
nodules, or powdery deposits. The required measurements of operating
performance shall be conducted and documented by the qualified Coating
SECTION 09971A
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