Mastic applied over dirty/oily duct
Do not seal over oil, dust, or dirt. Clean the metal first so the approved sealant can actually bond.
Stop if
- This joint is dirty/oily before sealing. Do you want it cleaned and resealed with the approved method?
Watch out
- Do not smear mastic over dirty, oily, wet, or loose surfaces.
Check
- Stop sealing that joint.
- Wipe/clean the duct surface per site/product direction.
- Let wet areas dry before sealing.
- Reapply only after the metal is clean and tight.
- Ask before trying to hide a dirty joint with extra mastic.
Steps
- Stop sealing that joint.
- Wipe/clean the duct surface per site/product direction.
- Let wet areas dry before sealing.
- Reapply only after the metal is clean and tight.
- Ask before trying to hide a dirty joint with extra mastic.
Say this to your foreman
This joint is dirty/oily before sealing. Do you want it cleaned and resealed with the approved method?
More in Sealing, Leakage, Mastic & Pressure Testing