Subcontracted Galvanizing and the Quality Record
A fabricator is supplying 180 tons of structural steel for a wastewater treatment plant, where corrosion resistance is critical. The specification requires hot-dip galvanizing per ASTM A123 with coating thickness verified and documented. The fabricator has no in-house galvanizing line and subcontracts to a local galvanizer. The galvanizer delivers coated steel with a certificate of compliance but no coating thickness readings. The fabricator's receiving inspection consists of a visual check for runs and bare spots. Two weeks after delivery, the owner's inspector requests the coating thickness records. The fabricator's project manager says the galvanizer's certificate is 'standard practice' and should satisfy the requirement. The project is 80% delivered. The fabricator's quality manual states that subcontracted special processes shall be verified by the fabricator before acceptance.
1. Evaluate whether the galvanizer's certificate satisfies the specification and the fabricator's own quality manual.
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The certificate does not satisfy either. The specification requires coating thickness verified and documented - a certificate of compliance asserts conformity but does not provide the measurements. The fabricator's quality manual requires the fabricator to verify subcontracted special processes before acceptance; a visual check for runs and bare spots does not verify coating thickness.
The gap is a commitment-to-quality and documented-procedure failure: the fabricator accepted subcontracted work without the verification its own manual requires. The 'standard practice' argument is not a defense - the manual is the fabricator's own commitment, and the specification is the owner's requirement. Both point to measurement.
What should have happened: receiving inspection should have included coating thickness gauge readings on a sampling basis, recorded and retained. What should happen now: the fabricator should measure coating thickness on the delivered steel, document the results, and disclose the gap to the owner's inspector with a corrective action plan for the remaining 20%.
2. The owner's inspector asks how the fabricator will handle the 80% already delivered. Propose a path that is defensible without scrapping 144 tons of steel.
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Scrapping 144 tons is not the first option. A defensible path:
- Sample and measure. Gauge coating thickness on a statistically valid sample of the delivered steel, across members and coating batches. Record results.
- Compare to ASTM A123. If the sample meets the minimum thickness, the delivered steel is acceptable and the records can be completed retroactively with a note explaining the verification gap.
- If the sample shows thin coating, identify the affected members and rework only those (re-galvanize or repair per the specification), rather than the full 144 tons.
- Fix the process for the remaining 20%. Add coating thickness measurement to receiving inspection and require the galvanizer to supply readings with each shipment.
This path is defensible because it replaces assumption with measurement, limits rework to what the data shows, and corrects the process going forward. The owner's inspector is more likely to accept a measured, documented response than a certificate and a promise.