On Wed, 20 Apr 2005 18:47:57 -0400, "Robert11"
wrote:

Hello:

Regarding all the round sheet metal duct work exiting our typical gas fired,
hot air heating
furnace:

What's the best way to seal these duct joints, at least where one can
actually see them ?

Duct tape doesn't really sound like the best way to go.

Would appreciate any suggestions as to brands, etc.

I guess I should also ask:

Is it necessary to do so for the hot air ducts ?

How about for the duct leading to roof flue exhaust (no fireplace in house)
?

Thanks,
Bob


Forget duct tape (any brand, any manufacturer) as being
the BEST product to use. you want a brush on duct
sealer/mastic. Not roofing mastic, nor any petroleum based
product. the best duct mastics are water soluble & have
zero or very little flame spread. The better ones have
reinforcing fibers mixed in. These products are not
typically sold at home depots or DIY home centers.

do not apply duct tape or duct sealer to the exhaust
venting. check the building codes for your geographical
area.

try these sources:

http://www.hardcast.com/products/pr_detail.asp?pid=1

http://designpoly.com/sealants.htm

http://www.wardind.com/Products/Sealants.htm#swb-n

http://www.mcgillairseal.com/textDoc...lex_Mastic.htm