On Fri, 14 Mar 2008 17:46:47 -0400, mm
wrote:

Hi! I have a steel fireplace, 29 years old, with a round metal
chimney and a metal damper. I've used it may be 50 times. Now I'm
having trouble shutting the damper.

I forgot to say that I looked up at the damper and it's a round metal
disk with a pivot rod accross it in the middle, and on the side that
goes UP when the damper is open, about half way across that half is
attached a long rod that goes down the fireplace opening. That's the
control. Because the damper opens all the way to the point that the
round metal disk is vertical, pulling down doesn't cause much lateral
force, so the disk doesn't rotate on its pivot and it doesn't move at
all. If it were a lot bigger than 10 or 12 inches and I could get in
there, maybe I'd just put in something that kept the damper from
getting totally vertical, but I think it was built the way it is now,
so I think there's a better solution anyhow.