boiling glass

[jerry keller]

I recently forgot to put the thermocouple into the chamber after loading my small kiln. It was in the wall of the kiln, so registered temp., but only in the hole in the wall. Went to 1375 for 45 min. The results were at first surprising, and then I decided I liked what happened. Any idea what temp it might have gone to, or what temp I could program it to , to create a boiling effect in 96? The pieces I'm doing are about 6"x4".

I know the elements will take a beating using this technique - any idea how much more this burns out an element? ( 20 firings like this vs. maybe 150 in a normal situation ?)

[Bert Weiss]

Many kilns are rated to fire up to 2300°F, which is a midrange working temperature of a glass furnace. So, if your thermocouple was embedded in an insulated space, the kiln would be firing at full power trying to fulfil the program. 2300 is hard on the elements and on the brick, as well as on the glass.

[Stephen Richard]

To answer your question - 900C should be enough for the creation and collapse of bubbles. the time you soak at top temperature is up to your observation.
How hard this temp will be on your elements is open to debate.

[GuyKass]

And in regard to your first question, "what temperature did you actually fire at?" seems fairly easy to ascertain.

Pull the probe back to where it was embedded in the brick and not in the chamber, fire as you did before, and when you are pretty certain you are the max temp, push the probe back into the chamber. That will at least give you the temperature you were at last time.

Just a thought.

Guy

[jerry keller]

Thanks for that - I also looked up the kiln specs, and it fires to 1700, so couldn't have gone much higher than that...