Stainless Duct Was Worked With Carbon-Steel Tools

Fast answer

Isolate the affected area and verify the project’s contamination-removal and acceptance procedure. Carbon-steel residue can embed in stainless surfaces and later show rust staining.

What to check

1. Identify which tools, abrasives, clamps, tables, and brushes contacted the duct.
2. Photograph affected surfaces.
3. Check whether the finish is architectural or process-critical.
4. Verify cleaning, passivation, testing, or replacement requirements with the responsible party.

Do not

Do not hide contamination with polish, paint, or an unapproved abrasive.

Ask the foreman

“Carbon-steel clamps and a used wire brush contacted this stainless section. I documented the areas and stopped work. What approved cleaning or acceptance process applies before we continue?”

Why it matters

Embedded iron can corrode and contaminate a specialty system even when the stainless itself was not deeply scratched.