My HVAC unit is up in the attic. It works fine - I just cleaned the
coils - but at each end, where the unit connects to the main intake and
output ducts, it's wrapped with this plastery-looking material. It
looks like strips of cloth that have been soaked in Plaster of Paris,
or maybe wheat paste. Some of it has cracked and is leaking air, so I
want to replace or add another layer to it. Can somebody tell me what
this stuff is? Hopefully it's something I can buy cheaply at Home
Someone else here may know better than I, but that sounds exactly like
asbestos. It used to be widely used as fireproof insulation for
ductwork before it started killing people.
Leave the stuff alone unless you're absolutely sure that is NOT
And if it IS asbestos, don't repair it. Either leave it alone or
remove it properly (expensive).
No, no, no. It's not asbestos. Not even close. This is where the main
duct attaches to the central unit. It's just to attach it and seal it
at the connection. It's a light cream/white color, and as I said, it
looks like strips of cloth that were dipped in plaster of paris, then
wrapped around the duct and allowed to dry.
IF you want something similar go to an autoparts store and look at muffler
tape. There is a brand just as you describe , cloth tape with plaster of
paris, that you soak in water and wrap around the exhust pipe to seal leaks
You are looking for duct sealant like CP 11 from Childers:
Keep the whole world singing . . . .
DanG (remove the sevens)
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