My local brickyard has bags of something called "Fire clay" which they instruct me to mix with portland cement to make a fire brick. I suspect that this is wrong (or useful only for fireplaces). My intuition tells me that I should form it into my shape (I have a special shape in mind) and then have it fired like regular clay.
Am I right? If I make a special shape with fire clay, then fire it properly, will I have a fire brick I can use? If so, what are the criteria for firing it properly? Any limitations or requirements or discussion would be welcomed! My web searches have not been fruitfull.
BTW, my wild clay turned out to be merely a sticky-ish dirt. No amount of firing short of melting it into glass beads would turn it into ceramics. As a glaze it is a pretty copper but completely undurable.
Thanks in advance, Bill