3.7.2.3
Application of Intermediate Coat
Apply intermediate coat within RECOAT WINDOW of primer coat.
3.7.2.4
Application of Topcoat
Make all required repairs to primer and intermediate coats as specified in
paragraph entitled "Procedure for Holiday and Spot Repairs of Newly Applied
Coating" prior to applying topcoat. Apply topcoat within RECOAT WINDOW of
intermediate coat. The polyurethane topcoat may require multiple passes to
achieve desired aesthetics and required thickness. Consult manufacturer
for thinning and application procedures for anticipated temperature,
humidity, and wind conditions. Touch-up blemishes and defects within
recoat window of polyurethane topcoat. Retain sample of polyurethane
topcoat, from the same batch used to coat structure, to make touch-ups that
might be required later.
3.7.2.5
Application of Joint Sealant
Apply joint sealant to back-to-back steel joints that are less that 3/8
inches wide and are not seal welded. Apply sealant to top and bottom, or
each side, of narrow joints. Apply sealant within 48 hours of application
of the topcoat, and touch-up with topcoat after appropriate cure of the
sealant.
3.7.2.6
Procedure for Holiday and Spot Repairs of Newly Applied Coating
Repair coating film defects at the earliest practicable time, preferably
before application of the succeeding coat. Observe all requirements for
soluble salts contamination, cleanliness between coats, and application
conditions. Prepare defective area in accordance with SSPC SP 10, and
feather coating as required to leave 100 mm 4 inches of each succeeding
coat feathered and abraded. Protect adjacent areas from damage and
overspray. Remove dust and solvent wipe the prepared area plus an
additional 100 mm 4 inches beyond the prepared area with clean denatured
alcohol. Apply each coat within RECOAT WINDOW of preceeding coat. Within
four hours of preparation, apply zinc-rich primer to prepared steel and
feather onto prepared primer. Apply intermediate coat to primed area and
feather to prepared intermediate area. Apply topcoat to intermediate coat
and feather to prepared topcoat. Apply each repair coat to approximate
thickness of surrounding coating system.
3.7.2.7
Structure Occupancy After Coating Application
Use clean canvas or other approved shoe covers when walking on coated
surfaces, regardless of curing time allowed. For heavily trafficked areas,
provide cushioned mats for additional protection.
3.8
FIELD TESTS AND INSPECTION
For marking of tank surfaces, use chalk for marking bare steel, and water
based markers for marking coated surfaces, and remove marks prior to
coating. Do not use any wax or grease based markers, or any other markers
that leave a residue or stain.
3.8.1
Coating Inspector
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NOTE: Include requirement for NACE Coating inspector
SECTION 09971
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