TinnerFlow™2nd YearRound, Spiral & Flat Oval DuctCheck first
Once the lockseam unzips, that damaged area is not a normal sealant fix. Cut back to sound pipe and lock the seam end before installing.
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A recip saw or rough cut can grab the spiral lock and start unzipping it like a ribbon. When that happens, the pipe loses the structural lock that makes it round and strong.
Trim past the damaged area with a cleaner cutting method, stabilize the remaining seam end with approved fastener/rivet direction, and replace the section if the seam damage continues into the usable length.
Use this as training guidance. Foreman direction, approved drawings, project specs, manufacturer instructions, employer safety policy, and AHJ/code requirements always control the final answer.