We recently did a test firing of some cone 6 clays in our old-time Skutt kiln (model 1081 or 181?) to cone 04. The pyrometric bar in the kilnsitter melted to a perfect u/v shape & turned off the kiln, but the 04 witness cone we placed near our test tiles apparently didn't melt at all. Also, the test tiles in this kiln sound less bell-like when we tap them against each other than the ones in our Skutt 818 programmable kiln.
1) How do you tell when a piece is completely bisqued?
2) (Assuming our test tiles really aren't completely bisqued like I think they probably aren't), what should we do to be sure the kiln is doing enough heat work? Should we put 03 bars in the kilnsitter?
I'm a tolerably experienced potter, but a total newbie at firing, so any and all advice from those of you with more experience will be very much appreciated.
Thank you,
-Kristina Vatne