The only sure way is to do some firing tests. The raw color is not really an indicator since dark grays can turn red or buffs when fired etc. The one I use is a tan from the ground but brick red fired to earthenware and brown just before slumping. Usually red fired are earthenware but in Oregon I found one that was stoneware. I would dig 5 gallons, process it then make complete pots and let the whole load be a test. Run to 1800, check higher till vitrified (rings when tapped) and no slumping.
peace i am a clay artist from mississippi..
jmg1957 1 year ago
alright man thanks for the tips ill have to try that soon
happy potting
ratmfan105 2 years ago
when digging up your own clay, how do you know what it's max temperature it can be fired to?
ratmfan105 2 years ago
The only sure way is to do some firing tests. The raw color is not really an indicator since dark grays can turn red or buffs when fired etc. The one I use is a tan from the ground but brick red fired to earthenware and brown just before slumping. Usually red fired are earthenware but in Oregon I found one that was stoneware. I would dig 5 gallons, process it then make complete pots and let the whole load be a test. Run to 1800, check higher till vitrified (rings when tapped) and no slumping.
prairiefires 2 years ago