I am making my own low temperature kiln shelves (from a 50:50 mix of Pyrax and Kaolin with 20% grog added). How can I dry them flat? Like this. You might think that the weight of the board above would impede the shrinkage of the slab and crack it, but that does not happen.
Drying Ceramics Without Cracks
Anything ceramic ware can be dried if it is done slowly and evenly enough. To dry faster optimize the body recipe, ware cross section, drying process and develop a good test to rate drying performance.