Kiln Explosion

When air gets trapped inside a clay piece it expands when it is heated in the kiln.  This causes an enormous amount of pressure to build up inside the clay piece.  If the pressure gets strong enough, the clay piece blows up in the kiln.  Sometimes this results in cracks or pieces being blown off.  Other times the clay piece literally explode and the clay pieces shattering around are blown out like shrapnel from a bomb.  This can destroy neighboring pieces.  I had three pieces that had walls that were too thick or air that was trapped inside from non-sufficient wedging.  This caused a massive explosion during my last kiln fire.  Students always seem to be excited when I talked about this, so here are pictures.

Don't worry, grades are not affected by pieces that did not survive.  Students will have an opportunity to re-make their piece if they want to also.