"peter" wrote in message
news:CDy%e.2738$kl3.322@trnddc08...
Some of the air duct from the furnace to the registers are several shorter
ducts joint together. A while ago I found some of those joints failed and
separated in the crawlspace. The ducts look to be 8 to 12 inches in
diameter, and they want to pull away from each other at the joints,
perhaps
the ducts were taut when installed. I duct taped them back. Although they
hold, they seem to be leaking air.

What is the best way to seal the joints?



lots of options, but depends on the type of "hole"
Are you sure there isn't crimped pipe joints that came apart ?

Duct tape is easiest, and you can get different grades, some is garbage,
some will last years.
it is also available in either the cloth or metal types.

You can also buy what we call ductseal, a brick of caulking type compound
that you press in like play dough.
(electrical and refrigeration wholesalers always have it)

Or even pop rivet another piece of metal over the hole.

Even just regular silicone caulking may work.

AMUN