bisque fired fine but melted during glazing

[Rae Reich]

Put cone pads on every shelf, even before you make spy holes they can tell you a lot when you unload about the evenness of the firing, cool spots, etc.

[Chilly]

On 4/27/2018 at 4:06 PM, dom92 said:

I'll pick up some cones the next time I'm at the store.  Until now I've hesitated on using them because my Skutt kiln has no spy hole.  The only way I'd have to check a cone would be to open the kiln, and I like to avoid doing that so I don't cause unneeded stress to the piece I'm firing.  

Cones without the spyhole will still tell you if the kiln overfired.

[Ceallach]

On 4/26/2018 at 6:20 PM, neilestrick said:

Ultimately, the thermocouple should only be used to show approximate temperature and rate of climb. You need to be using cones to determine the actual heat work, or you'll never get any consistency in your work, and could do a lot of damage to the kiln.

I keep saying this to people on other sites.....that the best way to determine the impact of temperature on clay is to measure it with something that responds to heat and time like clay, and that only  a cone can measure heat work accurately, because it really measures the absorption of heat by the clay over time.  
Honestly, I had worked with clay for decades before even hearing the term 'heat work', and then it made so much sense.

[Mark C.]

Put cones on 3 layers in new kilns to see what’s going on until you get it adjusted 

Back in the 70s in art school in clay and glaze glasses we called it time and temperature which now is simplified into heat work cones are the only true indicators