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Apprentice answer

What's the trick to cutting duct liner so the edges don't fray

1st YearInsulation, Liner & CondensationCheck first

Use a razor-sharp insulation knife or a long carving blade. Compress the fiberglass flat with a straightedge steel ruler along your cut line, then slice through cleanly in one continuous stroke.

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Plain-English answer

Use a razor-sharp insulation knife or a long carving blade. Compress the fiberglass flat with a straightedge steel ruler along your cut line, then slice through cleanly in one continuous stroke.

Field checklist

Ask Foreman

Hey boss, I’m checking sealing & insulation: What's the trick to cutting duct liner so the edges don't fray? I found the likely issue and want to verify the next step before I lock it in. Do you want me to adjust it now or check the drawing/detail first?

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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