By the time of the third firing we had modified the kiln by introducing a bag wall to draw the hot air and flame up which resulted in cone 8 bending (see larger image).

There were the tell tale signs of soda throughout the kiln which the test pieces show (see larger image).

We will fire the kiln, which is beginning to disintegrate, once more and impede the air flow at the exit flue to encouage the temperature to rise.

  The front central brick of the 19th course (see larger image) will transfer much of the force of the chamber arch from the 'springer' bricks to a metal bar held in place by the corner angle iron posts.

This photograph (see larger image) and yesterday's one shows how the damper system was built.  When closed the flue will be completely sealed allowing the kiln to cool down slowly.

Despite the mud the kiln build continues and the 16th course is finished. The photograph (see larger image) shows the 15th course with the fire bricks on which kiln shelves will sit and act as a damper.

Now that the fiddly work has been done and most of the remaining bricks will be insulators it won't be long before the kiln is finished.

The photograph (see larger image) is of the 11th course with the passive damper brick centre front. This will also act as a spy hole as when removed the chamber is visible through the exit flue.  

Although the ground was waterlogged it was warm enough for the high temperature castable to be laid today. It is forecast to remain above freezing for the next few days so it should set OK.

Kiln shelves will be placed on the castable to create the chamber floor so it was necessary to make a special float to cater for this (see larger image).