river clay firing problem
Posted 14 May 2012 - 07:48 PM
I dug some clay in a river a couple of years ago. After sieving it we decided to test it and we cooked a tile in an electric oven around 1000 C for biscuit. it worked very well.
we did some low temperature glazing. The first result was fine but a couple of day later the tile cracked by itself. Inside was some white lump.
Does anyone have an idea of what is the problem and if it can be fixed?
Thanks very much
Posted 15 May 2012 - 10:43 AM
Thanks for your answer. It is the first time I use a non commercial clay.
The sieve was not that fine, but there were quite many of them and more like a flour lump, something that probably agregate during the cooking. My teacher was also surprised and had no idea of what could have happen or what could be the chemical provoking a crack a couple of days after cooking
Posted 15 May 2012 - 11:23 AM
Kiln Repair Tech
Owner, Neil Estrick Gallery, LLC
Posted 16 May 2012 - 10:07 AM
thanks, I will try
Posted 16 May 2012 - 10:09 AM
Thanks for the tip! This tile though was only for fire testing the clay.