Glass Casting

This week in the sculpture studio, our glass castings will finally come out of the kiln after casting and annealing for over a week. I had the opportunity to check the pieces while they were still casting in the kiln at 1,550°F.

To cast each piece, water was poured into each mold and measured then converted into a glass measurements. The glass was then broken into small chunks and placed into the cup of each mold.

Molds waiting to be filled with glass
Molds with glass loaded into kiln

After the glass had started casting, sculpture tech Maddy asked if I could help her check the molds to make sure all of the cups still had glass in them and that nothing had cracked.

For this, we had to put on heat resistant jackets, hoods and gloves. The reason they look so Sci-Fi is because of the outer layer of aluminum which refracts the heat from the kiln.

Maddy explaining to me how far she wants me to open the kiln.
Taking a peak.

The kiln could only be cracked open for about five seconds at a time since we did not want to allow too much heat to escape. The temperature would start depleting as soon as we opened the kiln, so in between checks we had to wait for the temperature to make it back up to 1,550°F.

Kiln set at glass casting temperature.
Molds casting at 1,550°F
Maddy checking the kiln in protective gear.

All of the pieces looked good after casting for about 8 hours. Now they are well into the annealing process. The time it takes to anneal is based on the thickest piece in the kiln. For this batch, it took about a week to slowly bring the glass down to room temperature.

Remember, do not mess with active kilns.

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