Firing

          The completely dry pot, now called greenware, is still quite fragile.  If handled roughly, it can easily chip or break.  If water is added to it, the piece will soften and become clay again.  It must be fired if it is to become a useful vessel.

          The first firing is the bisque (or biscuit) firing.  Since no glaze is applied at this time, pots may be stacked or placed inside each other in the kiln.  After the kiln is loaded, the lid is propped open a couple inches, then turned on low overnight, warming the ware slowly.  The lid is then closed and the temperature raised to over 1800˚ F.  During this process, all the remaining water is driven off and the clay changes to porous "stone" which holds its shape, but still chips easily and is not very durable.  Bisque ware absorbs water, but does not return to clay due to the chemical changes which occurred during the firing.  When the firing is complete, the kiln is allowed to cool before it is unloaded. 

          Before glazing, bisque pieces are wiped with a damp cloth to remove any dust which may interfere with the glaze adhering to the pot.  To prevent the pot from sticking to the shelf during the final firing, the foot ring is waxed before glazing and any droplets of glaze are wiped off before the pot goes into the kiln.

           The pot may be decorated with underglaze, which is applied to the bisque ware before it is glazed.  Among many other options for decoration are layering several different glazes and brushing stains on the glazed pot.  Different glazes chemically interact during the glaze firing, often producing interesting effects.  Possibilities are nearly limitless!   

          Glaze may be applied by pouring, brushing, or spraying, or the pot may be dipped in the glaze.  One to three coats of glaze may be applied, and all coats may be of the same or different glazes. 

          The dried glaze is easily chipped off pots or damaged if not handled with care.  Pots are now loaded into the kiln again, leaving at least 1/2" between pieces.  Pieces which touch in this firing will be "glued" to each other permanently!  The kiln is fired to a final temperature of about 2200^o F.  During this firing, the clay matures to dense stone and the glaze chemically bonds with the clay.  The kiln is allowed to cool until the pots can be handled with bare hands, approximately 120˚F., and then it is unloaded.  Each piece is inspected and any rough spots on the foot ring are smoothed off. 

          The journey is now complete!  The lump of clay we started with has now become a finished usable piece.  The glazed ware is durable, chip-resistant, and waterproof... and it is beautiful!

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