What do I do before putting mastic or tape on the joint?

Clean the surface and confirm the joint is mechanically seated first. Sealant sticks to clean metal; it does not fix loose, dirty, oily, or damaged fit-up.

Make the joint mechanically right before sealing or covering it. Sealant is not a substitute for a loose or dirty joint.

Rectangular Duct & Fittings 2nd Year YELLOW

Stop if

Ask when the approved sealant method is unclear or the leak is caused by damaged metal instead of surface sealing.

Watch out

Do not seal over gaps, dirt, oil, water, or a loose joint.

Check

Confirm the joint is tight
Clean dirt/oil/water from the seal area
Use the approved seal method

Steps

Check S/slip and drive seating.
Remove dust, oil, shavings, and moisture where sealant goes.
Use the approved mastic/tape/sealant.
Tool/press it as required.
Recheck corners and access points.

Say this to your foreman

In Rectangular Duct Assembly: S-and-Drive, I'm looking at: What do I do before putting mastic or tape on the joint? What should I verify before I cut, drill, seal, cover, move, or install?