On Mar 15, 10:33 pm, "John Grabowski" wrote:
"TKM" wrote in message

...

What kind of insulation is used on hot air furnace pipes and the sheet
metal
of the furnace plenum? I'd also like to seal the seams and joints which
leak
hot air and have heard there is some kind of liquid sealer for that.

Thanks,

TKM

For insulating ducts I use duct wrap insulation. Usually 1 1/2" thick, but
I think it comes in other sizes also. You can use foil tape to seal joints
and there is also some caulk products that I have seen used, but I don't
know the names. Try a plumbing supply for these materials if you can't get
them at a home center or hardware store.

For small leaks in the plenum, you can use silicone caulk (RTV) in
clear or silver. Home Depot carries duct wrap and the tape for it, as
well as insulating sleeves for 6" ducts. Any big insulation supply
house will have everything you need too, but they may or may not sell
to the general public.

You can also use "Thumb Gum" for the small leaks.

JK