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Fire Magic Symposium 2001
constructing the arches for the doors and fireboxes
 
     

1. One of the firebox arches. The former is made from a piece of plastic strip. This easily and naturally makes a catenary shape when bent.

2. As the arch grows ythe former needs added support with lengths of timber. These are easily knocked out when finished. Occasional rows of brick are laid lengthways through the arch wall to give added structural support to the coarses of brick.

3. The first two rows of the arch are complete. As soon as the key bricks are in place the former can be removed and the arch is self supporting.

4. The former removed showing the free standing catenary shape. You can also see the gently sloping side walls of the kiln. These also provide the angle for the skew-bricks and support the arch.

5. The view of the arch from outside the kiln. This clearly shows the construction of the firebox with the inset bricks to support the grate bars.

6. Placing the second former to support another two courses of arch brick. This was necessary to elongate the fireboxes and also to save on castable material later.

7. The extended former is again supported by temporary wooden battens. These allow the former to be adjusted to fit the required profile exactly.

8. The key bricks at the top of the arch are tapped into place. These bricks are the most crucial as they provide the strength in the arch.

9. Once the key bricks are in place the former can be removed

10. View of the kiln from the other arch.
These arches are both the doors and the fireboxes.

11. Laying the final course of brick up to the edge of the arch.
As the roof of the kiln will be cast with refractory cement
the angle of the kiln wall will support the finished structure
and prevent it from bowing outwards.