We are short on 24x24 duct, but we have a plasma cutter and flat stock. How do I fabricate it entirely in the field?

Calculate your complete metal blank layout wrappers allowance factoring in the standard 1/2-inch allowances for the Pittsburgh corner seams and S&D connection tracks. Program or manually trace your cut lines out onto your flat galvanized stock sheet panels. Cut the profiles cleanly using your tools, run the long edges through your field pocket-lock machine or hand seamers to knock the matching Pittsburgh wrappers together, and true up the box profile using a framing square before driving the s

['Calculate your complete metal blank layout wrappers allowance factoring in the standard 1/2-inch allowances for the Pittsburgh corner seams and S&D connection tracks. Program or manually trace your cut lines out onto your flat galvanized stock sheet panels. Cut the profiles cleanly using your tools, run the long edges through your field pocket-lock machine or hand seamers to knock the matching Pittsburgh wrappers together, and true up the box profile using a framing square before driving the seams home.']

Stop if

• Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.

Steps

• Stop and verify the approved detail, manufacturer instructions, foreman direction, and project specs before touching it.
• Calculate your complete metal blank layout wrappers allowance factoring in the standard 1/2-inch allowances for the Pittsburgh corner seams and S&D connection tracks. Program or...

More in Apprentice Workflow, Communication & Learning