Erik Weaver wrote:Thank you. I had forgotten that equation, if I had run across it before.
I've just about finished re-building my dry stack test bricks. I've made the fire box out of fire brick slips this time ("half" size) roughly 1.25" thick, all the way along the bottom (first course) and sides (second course). Then along one side I immediately stacked a full size fire brick right along side the slips (but not the bottom). This will allow me to slide a thermometer along each side and compare the temps, one just the slip width (about 1.25") and the other slip + full brick (roughly 1.25 + 2.25 = 3.50" total wall thickness). I hope to get that test burn done tomorrow.
Erik Weaver wrote:I've been too busy at work to check some diagrams, but it seems to me that the double walled fire brick at set up tight against one another. The card board, fiberglass, rockwool, etc, used to provide expansion gaps is placed between differing materials, not materials with the same expansion (as I recall).