John Tiemann on mon 26 apr 04
I have been wanting to do some saggar firings with my high school students. We usually fire up the Raku kiln with the weather getting nicer, but I thought of trying to do some saggar firings in the raku kiln instead. I have a few questions if you would be willing to help me and my students out...
1. Is it true that saggar firing in an electric kiln is bad for the elements? I remember seeing an article in either clay times or PMI that talked of firing saggars in an electric, but others told me it was bad for the elements even with proper ventilation.
2. What temperature do you try to reach when firing a saggar in the raku kiln? I have heard mixed results anywhere between ^08 - ^10. Is this temperature inside the saggar or the kiln?
3. At what temperature does the burnished "shin" fade from the piece?
4. How much cooler is it inside the saggar than outside in the kilns atmosphere? How do you compensate for this?
4. I have made a ceramic jar for the saggar... do you use a lidded container or build the saggar out of kiln bricks? What seems to have better results?
5. Do you seal the lid of the saggar with kiln wash or a kiln shelf? How much smoke do you want comming out of the saggar (How much is too much?)
6. How fast/slow do you allow the kiln to cool before removing the saggar?
7. What materials (combustibles/chemicals) do you find to work best with your saggar firings? I know many materials are toxic, what do you recommend staying away from with high school students? (aluminum foil, copper sulfate, etc.)
I know this is a lot to ask, but any help would be greatly appreciated! Thanks so much for your time and I hope to hear from you soon.