TinnerFlow™How do I fix a stripped TDC or Ductmate corner bolt
2nd YearDuct Assembly, Seams & JointsStandard Correction
A stripped corner cannot clamp the gasket. Replace or through-bolt/back up the failed hardware per shop standard before pressure or startup.
Plain-English answer
The corner bolt is not decoration; it pulls the flange corners tight so the gasket can seal. If the nut strips, the corner may look connected but the joint can gap, whistle, or leak under pressure.
The usual field correction is to remove the bad bolt/hardware, install approved replacement corner hardware or a backed-up through-bolt/washer/nut repair, and recheck gasket compression and flange alignment. Do not fill a loose corner with silicone and leave it mechanically loose.
Field checklist
- Confirm which corner stripped and whether the flange is bent or misaligned.
- Check gasket placement at the corner and whether the joint is pulling evenly.
- Remove bad hardware and inspect the corner piece.
- Use shop-approved replacement hardware/backing method.
- Recheck clips, corners, and sealant after tightening.
Ask Foreman
The corner bolt/nut stripped on this TDC/Ductmate joint at [location]. I checked gasket and flange alignment. Do you want replacement corner hardware or an approved backed-up through-bolt repair?
Verify before acting
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.
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