Greenfire

Thank you for taking an interest, Monkey and Thomas! I have not checked around, and I don’t have the first idea how to check something like that…I guess I could look up refractories or something…. I am in Wisconsin, so if YOU have some idea where to look in the Midwest, please let me know. Monkey, yes, I’m kind of thinking I could use some regular brick to make a temporary kiln to make permanent firebrick- I have a lot of salvage bricks, which I did use to make an oven for a charcoal retort (for the garden), but the bricks did not hold up well at all. I have since come across other ideas to smear an insulting layer of mud inside the brick structure (even for a permanent masonry heater), but have yet to attempt…this might be a good place for perlite additive to keep extreme heat from the regular clay brick. thanks again guys! (I mean that in a non-gender specific way!

Hi. Not sure if anyone is out there still watching this conversation started in ‘07 or so, but I found it, so maybe… I’m coming at the issues from a slightly different angle: I want to build a Kuznetsov Russian (masonry) stove. (Check stove.ru if interested and click the little Aa button to translate to English) It will be a high-temp wood burning heater. I believe temps in the firebox could exceed 2500 degrees F. The intent is for a hot fire to heat up a mass of masonry that then radiates to heat a space over the course of many hours. These stoves are typically built as an inner layer of firebrick, a narrow expansion break, and an outer layer of normal building brick or stone or other high-mass material. So the firebrick is not intended so much for insulation as for just a tough inner shell that can take the harsh conditions of wood combustion. Actual full Chamotte bricks are like 6 bucks apiece, plus shipping, and I may need a couple hundred of them, so I am looking for an alternative for my first attempt at building one of these. Also, there’s a likelihood that some stray building or insurance inspector will come sniffing around and tell me to dismantle it, so I don’t want to spend that kind of money on an experiment and am planning to make my own bricks. I dug up some clay from the backyard, but I’m not quite sure what to mix in. I have perlite, wood ash, sand, and mineral wool or rock wool. Kind of leaning away from perlite, as I feel a dense not-really-insulative brick is what I am after. Not too many here talking about wood ash, but seems to me like a good additive - it’s already burned, what can happen to it? I sifted it through a window screen, so it’s pretty clean, but still has some tiny charcoal bits in it, which may not be bad, since they will burn inside the brick and create tiny air pockets to give a some slight insulative quality. I’d be interested to read anyone’s thoughts on any part of this idea Thanks!