Stop and verify the cut before touching exposed/finished duct. Visible duct, painted duct, stainless, aluminum, architectural duct, or shop-finished duct can become a finish/punch-list problem if you cut it like hidden duct.
Ask when the duct is visible, painted, stainless, aluminum, coated, architectural, owner-facing, or the cut location/finish repair is not clearly approved.
Watch out
Do not freehand cut exposed duct, scratch the visible face, leave burrs, burn the finish, or assume touch-up is allowed without direction.
Check
Verify the drawing/detail and exact cut location
Confirm material and finish: galvanized, painted, stainless, aluminum, coated, or exposed architectural
Mark the cut cleanly
Protect the visible finish
Use the approved cutting method/tool
Deburr sharp edges
Ask about touch-up, sealant, cap/trim, or replacement before final.
Steps
Verify the drawing/detail and exact cut location
Confirm material and finish: galvanized, painted, stainless, aluminum, coated, or exposed architectural
Mark the cut cleanly
Protect the visible finish
Use the approved cutting method/tool
Deburr sharp edges
Ask about touch-up, sealant, cap/trim, or replacement before final.
Say this to your foreman
This duct is exposed/finished. What exact cut line, tool, edge finish, and touch-up or trim detail do you want before I cut it?