The sand on the shelves largely succeeded in preventing molten glass from reaching the shelves, although we had some spills which stuck down a few of the batts that were supporting the pots. The shelves were cleaned up using an angle grinder.

The ceramic fibre cloth used to stop the shelves from rocking did its job, but was virtually completely destroyed by the heat (we now know that the firepit reaches 1200°C).

One of the stops for the bars of the grate had come loose and had to be stuck back with high temperature sealant and fire cement.

Two of the small shelves supporting the ceramic tubes had broken off, so needed to be glued back using fire cement.

Most of the normal cracks on both the hot face and the cold face had opened up, so once again had to be filled with high temperature sealant before giving the hot face another coat of zircon silicate slip.

The firepit cleaned up well, although there were a few small splashes of molten glasss, which was only to be expected.

The preparations mainly consisted of adapting the left-hand side of the furnace so we were able to use it for making Roman-style window panes.

We did this by using concrete setts to support a 24" x 24" concrete paving slab. On top of the slab we laid two large ceramic kiln batts and and some firebricks to achieve the correct height.

The long-handled metal support (akin to a pastorello) for the batt which would be used for shaping and re-heating the window panes ran on top of the fire bricks by means of a metal roller. The metal support could also be slid to the right, allowing Mark to work on the pane after its re-heat.

We also made some domes from daub which were to be used for slumping window panes to create domed panes. These can be seen in operation in the photos of window pane making during Firing Four.

We used one set of shelves, built a low wall around each shelf and filled the space with sand.

The pot we used for holding the window pane glass was a larger circular one, 9.75" in diameter and 6" deep. It would be easier to gather large double gathers from this pot instead of the large 'swimming pool'-shaped pots that we used in 2019, although they held the same amount of glass (c.7kg).

Finally, we fitted new thermocouples and protected them with some ceramic fibre blanket. This meant that we could now record temperatures both above and below the shelf: effectively in the firepit and in the melting chamber.