Kilns and Kiln Problems

[Ian]

Something else I have been asked is what to do about a kiln lid that has real problems with dust etc falling on to the glass. The best I have come up with is here. http://www.bigceramicstore.com/Supplies/ITC.htm.
I havn't tried as I don't have this problem but looking at the way it it is used it does look like it will solve the problem. In the normal course o events vacuuming the element grooves before firing is all that needs to be done but some kiln brick just seems to be very bad at dropping dust etc due to the elements expanding and contracting in their grooves and acting like a file rubbing the kiln brick and priducing bits and dust. I sometimes wonder if this is due to someone crash cooling a lot.
Crash cooling is when the kiln is opened to drop the temp rapidly to stop the glass from moving eg like when stopping a dropout from hitting the floor of the kiln
A Dropout is when glass is slumped through a ring mold to form a vase. The glass is placed on a ring mold that stands on pillars so the the centre portion drops through.
Ian

[Becki]

Just a word about crash cooling...it was a common practice "back in the day" when there were no computerized controllers, usually to get the glass from process temp through the devitrification range quickly. It's no longer necessary, nor is it recommended.  It can be bad for kiln brick (I've seen lids totally destroyed by constant crash cooling) and, as Ian mentioned, rain brick dust down on your hot glass making an undesired design element!  I vacuum the inside the kiln and the lid before every firing and have never had a debris problem. Knock wood!

I do need to mention that the only time I crash cool is when I'm doing a drop ring or a floral drape and need to stop the process.

[Ian]

Tell me Becki when you do have to crash cool do you also feel the bricks squeaking and shuddering as the cold air hits them. It puts my teeth on edge like nails on a black board
Ian

[Becki]

Ooh, you mean the snap, crackle and pop of kiln brick threatening to disintegrate?  Irritating, isn't it??  I don't do drops or formers anymore unless requested.