I've got this old fireplace insert. For an assortment of reasons its dead to me and will never again be used as originally intended. I'm headed to the scrap yard soon and wondering if this idea will keep it around
What if I
a) Cut the back off at some spot calculated to have a certain volume in the box and then...
b) went all Frankenstein and stuck the metal bit onto a bunch of carefully arranged bricks* with a bunch of cob
Would I then have a clever box to function as a batch box? Its got a door that seals and that seems to be a big stumbling point on batch boxes. It also has the glass in it for an atmosphere bonus.
I'm sure I might need to do some interior surgery as well, maybe increase the airflow and strip out the "second burn chamber" in it. It has a shroud and a circulating fan that will have to go for sure.
I've used the front, door and sides of a small woodstove and have successfully built a 'sidewinder'batch box space heater that also heats water.
I followed Peters dimensions very closely and it works well. To create the correct firebox size and geometry I used a thin steel frame lined inside with a combination of hard fireclay and lightweight insulating firebricks.