There is no damper in my coal forge, it would be possible for a lot of cold air to come down the flue and enter the shop on these cold winter nights. A solid door keeps that from happening. It is an important detail which I didn’t illustrate in my previous posts about the forge construction last May.
The door panel itself is the drop from the water jet cutout for the door opening. The material lost in the kerf is just enough to make the door fit easily. It is 7 gauge HRS. I added some side strips in the front to serve as stops. A hole was drilled in the center of the arch canopy so I could drop a tapered keeper pin which matched up with a 1/2” pipe barrel welded to the door front. The keeper is attached to the door by a small chain about two feet long. That keeps me from losing it.
I still had a little trouble getting the door centered when putting it back in place so I welded two bottom guides which are easy to feel and provide an only-one-way fit.
It works perfectly now but there may be better ways to accomplish the same thing. For one thing, the door panel of 7 gauge weighs a lot and a thinner gauge would work as well. Also, a damper mechanism might be a more convenient solution.