Help with micro porosity in ceramic

[paulg100]

a frame that size will change the way the ceramic fires and throw more variables into the mix. Kara.

If you really wanna check whether you have hot spots your probably best to fire some single units. Put some in the middle and some at the edge and see if you still get pitting in the middle ones.

 

[Al.]

My first bake of emax I always fire on the high side for pit free and clear porc. Your others may seem pit free but under the surface they may be full of micro bubbles that will come to the surface next bake or glaze.

The first bake on MY furnace is 1420 F with no hold time. 1415 and I start getting those micro pits. For firing temps I dont even go by the manual. That is just a starting point. Every lab and furnace is different.

For me clarity and poris free are more important than slightly rounded edges I MAY get from a higher first bake. I can sharpen everything up the 2nd bake which will be at a lower temp.

Like Paul said the bigger the frame the longer it takes to get up to temp. I found layered Zir takes a higher temp to fully mature the layering porc.