Patch holes in ducts

Old 07-09-24, 04:47 PM
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Patch holes in ducts

In the hvac ducts in my garage are leaking air pretty bad. A couple of spots where pipes go into the ducts near the blower, the pipes were sealed with some sort of black, gooey tar substance and there is a minimal amount of tar where it is leaking.

My question is, what is this stuff and should I slap some more on there or should I try to pull it all off and use some metal tape?

Old 07-09-24, 05:49 PM
Tolyn Ironhand's Avatar
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I'm not sure what the black stuff is but these days HVAC guys use mastic. Example:
Old 07-10-24, 04:44 AM
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I use a mastic called Duct Putty. It comes in a tub and it's a medium to thick putty you goop over any openings or air leaks.

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