Damper won't stay closed?

[tananabrian]

We have a metal box fireplace and the damper won't stay closed. It's fairly clean, moves easily, but when closed all the way it then swings back open a bit. It's got a simple shaft with a handle on the front of it... Very basic.

Is it ok to add 'just enough' weight to one side of the damper? Can I just do something like screw a metal plate with a tight slot in it over the shaft where it come out of the top of the fireplace to add a little resistance to turning? Local shop says $415 to replace damper...

 

[dougand3]

I assume the damper completely closed is for non burning times? You do want at least a small exit open at all times during burning or smoldering. Eg: a pipe key damper has holes so smoke passes thru even when completely "closed". During non burning times, you could stuff insulation in chimney to closed off. Put a note in the firebox to remove insulation prior to burn or it will be a nasty surprise. Pics of setup will help answers.

 

[begreen]

Usually there is some sort of ratchet latching system or a stop detent that holds the damper shut. What make/model fireplace is this? (info usually on the inside door frame)