How do I use drift pins and C-clamps on TDC/Ductmate alignment?
Before the TDC/Ductmate joint seats against the gasket, support both sections, bring the flanges close, and use drift pins to align the corner holes. Once the duct is aligned on the pins, clamp the flange faces to hold that alignment, then start the corners/bolts and cleats or approved fasteners. Do not seat the joint first and try to drift it afterward-the compressed gasket can keep the holes from lining up cleanly.
Do not fully seat or bolt the joint and then try to drive drift pins through it. The compressed gasket can keep the corner holes from aligning and the pins can damage the corners or flange. Do not use drift pins or clamps to force a twisted, unsupported, or wrong-size joint together.
Check
Is the duct supported and level before the joint touches the gasket?
Is the gasket on one flange face only and are the corners on the joining duct?
Are the drift pins being used before the joint is fully seated?
Are the pins only aligning holes that are already close, not prying a twisted flange?
Are clamps applied only after pin alignment to hold the flange faces?
Are all corners started before final tightening?
Steps
Support both duct sections so neither joint is carrying the weight.
Put the gasket on one flange face only and the corners on the joining duct.
Bring the joining duct close to the fixed duct without fully seating or crushing the gasket.
Insert drift pins through corner holes that are already close and use the pins to bring the duct/flanges into alignment.
With the duct aligned on the pins, apply C-clamps or locking clamps to hold the flange faces
protect the gasket and flange.
Start all corners/bolts, then install cleats or approved fallback fasteners and tighten gradually.
Recheck level, square, gasket compression, and corner sealing.
Say this to your foreman
The TDC/Ductmate joint is close but not seated. I have the sections supported, the gasket on one face, and the corners on the joining duct. Do you want me to align it on the drift pins first, clamp it to hold, then start the corners and cleats?