June 9, 2014 - 10:24am
Used pottery kiln brick.
I'm thinking of building a second smaller rocket oven, but I'd rather reuse some used Pottery Kiln bricks that I salvaged.
My understanding is that some glazes could have contained lead: As long as it's not in direct contact with food, how safe would it be to reuse the brick?
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I'd use the bricks and not worry about the lead. If it's there, it would be in such low quantities. Divide that by the ratio of how much might escape and get in contact with food. Then, divide again by the amount of the food that one person may eat. "You're gonna eat the whole miche?" After all that math, think about all the much worse things you probably come in contact with in greater quantities than that. To me, the danger is small and insignificant. Simply crossing paths with cigarette smoke is more likely to kill you or make you sick, and how many times have we done that in our lives?
Fire bricks and kiln bricks there is a difference , the firebrick is very heavy compared to a normal house brick whereas the kiln brick is somewhat lighter than a standard house brick. the fire brick stores the heat whereas the kiln brick reflects or insulates against the heat. The fire brick is able to withstand the abrasive nature of fire and the loading of bread or trays directly onto them, the kiln brick is used for a lining for extremely high temperatures used in firing clay and ceramics but due to its porous and insulating qualities will break up readily with abrasion.
attached is a great link http://www.traditionaloven.com/articles/81/insulating-fire-bricks
Regards Derek
I agree with your differentiation of firebrick and kiln brick, but the kiln I salvaged had both. Long story short two electric kilns were being garbaged, so I grabbed them. The walls were made of the kiln brick you mentioned, very light, almost like ceramic styrofoam. There were also these slabs that go inbetween layers of pottery (I'm guessing) which are as heavy as firebrick.
The light brick might work well as an insulating liner, but probably not for heat retention. The heavy slabs I could see using as a roof for an oven, if I can ascertain they're not going to kill me.
Interesting link.
It's probably not a good idea to try reusing kiln brick for anything.
http://www.goshen.edu/art/DeptPgs/Hazards.html