What do I do if forcing the joint oil-cans the duct?

Stop forcing it. Release the pressure, support/re-square the duct, and find the cause instead of permanently bending the section.

Stop before the duct gets damaged. A duct end that is out of square, rotated, or oil-canning is usually telling you the piece or alignment is wrong.

Rectangular Duct & Fittings 2nd Year YELLOW

Stop if

Ask when the oil-canning stays after force is released or the duct will be exposed/critical.

Watch out

Do not force the duct until it buckles or locks in wrong.

Check

Verify orientation
Check squareness and cross-break direction
Confirm the piece belongs in that spot

Steps

Stop applying force.
Check support and elevation.
Check if duct is out of square or wrong size.
Inspect connector edges.
Ask if the section needs repair or replacement.

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In Rectangular Duct Assembly: S-and-Drive, I'm looking at: What do I do if forcing the joint oil-cans the duct? What should I verify before I cut, drill, seal, cover, move, or install?