|Monthly Tech-Tip |
It took 2-3 minutes to get this mug to soft leather hard for trimming using a heat-gun (not a blow drier). It took seconds to stiffen the handle for attachment after. I am now taking it to stiff leather hard to prepare for glazing (left). I dry it evenly by judicious technique. Then I pour-glaze the inside and immediately push it lip-down down into the glaze to do the outside. I re-gun it a couple of minutes and then re-dip the outside bottom (up to the previous glaze boundary). Last I gun it another 3 minutes an put it in the kiln. The lesson: The key is not drying speed. It is how even the drying is (I watch the color change and focus on the wettest parts). Finally I fire 400F/hr to cone 6 (with an hour soak at 250F for final water smoking). The clay: Plainsman M370.
Drying Ceramics Without Cracks
Anything ceramic ware can be dried if it is done slowly and evenly enough. To dry faster optimize the body recipe, ware cross section, drying process and develop a good test to rate drying performance.
Once fire glazing
Refers to the practice of firing ceramics in one firing (rather than two) to produce a fully glazed product. This practice requires more technical expertise.