I want to build this in my garage as a test case for replacing my open fireplace in my house.
As I'm sure a lot of you know, they built this using clay flue liners.
Where I live these are extremely hard to come by. My question is, could you build the bell towers that absorb using 16x8x6 cement blocks? That I line with either fire clay or fire cement.
According to there blog they see temps around 195 in the main bell, and 165 in the second bell. I'm also thinking about building the first bell that holds the j tube riser with cement blocks, and then lining it with the 1 inch ceramic blanket, and then lining the transition between bells with fire brick. Like this.
Also another question what would be a good heat retaining filler for inside the holes in the blocks? I can make cob, I have a lot of clay due to another project I have going. Or would a sand and vermiculite mixture be better?
Also if you see any other flaws with my plan I would be happy to hear them.