I like to cook and I use black iron frying pans. Good for your health. They get dirty. Next time you fire, put one of them in the fire for a couple of minutes. They won’t be dirty anymore.
Here is something strange.
I have glazes that melt at about 1170C. in my wood kiln. They melt at about 1100C. in my kerosene kiln. Same glaze, same clay, same pyrometer and probe. I think it has something to do with pressure in the kiln, the kerosene kiln has more positive pressure, or the volume of the kiln. My noborigama is about 25 times larger than my kerosene kiln.
Nanban ceramics 
Nice reading! I have had the same experience with glazes. I belive that it has to do with reduction. The glaze doesnt start to run before it is reoxidiced – something that doesent happen in the wood firings I am refferring to as much. Pressure and reduction is linked in some ways so maybe we are talking about the same fenomenon.
I like your site Stefan.
That could be the reason. I have a glaze that usually melts at 1150C. in my wood kiln that melts at about 1100C in my kerosene kiln.
Thanks!
If you come to another conclusion on the glaze melt I am very interested.
Keep up the posting!