The ten days of Firing Two had resulted in further shrinkage of the inner wall, which led to some of the repaired cracks opening up, as well as creating new cracks in the hotface. All of these were filled with high temperature filler and the inner surface was recoated with the zircon silicate slip.

The firing chamber floor had spills of hot glass mixed with ash stuck to the floor. We weren’t able to reach them with an angle grinder, so we cleaned them off as well as possible using a hammer and chisel.

Cracks also appeared in the outer wall, many following previous cracks, and they were also filled.

Two of the daub supports for the shelf support bars had fallen off, so they were reattached using the high temperature sealant.

The shelves had suffered from spillage of molten glass. The ceramic fibre cloth had offered very little protection, and the spilt molten glass had glued much of it to the shelf. After removing the shelves from the furnace, they were cleaned using an angle grinder, and replaced, using sections of ceramic fibre cloth to stop any wobbling (see photo in the 'Preparations for Firing Three' section below).

The repairs had been carried out in autumn 2021. These preparations were carried out in January 2022 – immediately before Firing Three, and largely consisted of making and fitting an upper layer of shelves to support shallower pots.

After shaping the upper shelves, we supported them on cut-to size HTI brick offcuts, built a low wall of daub around them and filled the space with sand to contain glass spills. We also placed kiln shelf offcuts on the shelves to support the pots.

We also had to replace the broken spacers either side of the firebars in the stoke hole. This time, we used kiln batt offcuts instead of fire brick offcuts.