Single Fire

After yesterdays schedule going a bit different than planned, I wasn't sure how wet or dry the work would be.  If it was too dry I could not glaze it for a single fire. Well, it was still wet enough that I was able to slip the pots and then glaze them. the exception was the wide mouthed jar with no lid. I set that aside to possibly Raku with Ferric.

I did not show pix of the pots glazed as, at this point, it doesn't show much. they were all liner glazed with Blue Fur.  The outside was glazed with Clear with the exception of the pot that was not slipped. That pot was glazed with Amber.  I did some further glaze on the lip of red or white, depending on the pot.

So Single Fire, or Once Fire. This means firing from greenware to glaze fire, with no bisque state. This is actually the way all pots were fired for most of the history of pottery. It is unclear when the idea of Bisque came to be, but widespread use did not seem to occur until the basic demise of the wood burning kilns The firing schedule is different, and in this case I am using the manual electric kiln.  A typical electric kiln firing is a "set it and forget it".  Even with the manual, it is a bit of baby sitting at the start but in three hours it is off on it's own. 

For the Single Fire, there is a lot more baby sitting.  Simple version... it is a slow climb to draw out all the water, eventually to chemically break the bonds of the water out of the clay (what happens at bisque) at which point the climb can continue to the target temperature (in this case ^6). So with this kiln, the process is slowed and facilitated by both the typical use of the kiln as well as keeping the lid open until the second half of the firing. This slows the heating and allows the steam and chemicals to escape easily. This prevents bloating of the clay or possible explosions.