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sparks on kiln shelf and schedule question

Submitted by janeinkcks on Mon, 08/20/2012 - 03:56.

General Fusing Discussion

I'm new at this so here come the stupid questions.

I have a barely used old kiln. It has coils on the top only and a thermometer for the temperature reading.

I have fired it twice: once to record the time and temp on each power level (Lo-8), & once to melt some bottles and scrap stained glass (fun).

Q 1: When I opened the lid to cool it down from 1500 to 950 there were sparks all over the kiln shelf. It looked like red glitter sparkling all over. It lasted about 10 seconds. Is that normal? I don't know what brand of kiln wash I used. I was given 2 small bags of wash. One of them said "kiln wash" and one said "glass kiln wash" so I used the later.

Q 2: When I cool the kiln from 1500 to 950 am I supposed to open the lid all the way or just a few inches. When I opened it all the way I could see the bubbles in the bottles get bigger.

Q 3: How do I slow down my initial heat up in an old kiln. It only takes 30 minutes for my kiln to heat to 500 on low heat. After an hour it's at 650. How am I supposed to slow the heating to 300 an hour?

The sparks you describe

Submitted by Paul Tarlow on Mon, 08/20/2012 - 05:39.

The sparks you describe sound like airborne dust that is floating into the kiln when you open it. The dust hits the 1500F air and ignite.

The faster you cool the kiln 1) the harder it is in the kiln and the elements. You don't need to crash cool - you can just let the kiln naturally cool. If you are going to open it, I recommend you only open it a few inches. Not sure why bubbles would grow as the result of rapid cooling.

What kind of controls do you have on the kiln?

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Paul
FusedGlass.Org
Helios Kiln Glass Studio
PaulTarlow.com