Clear Bowl and Goblet Stem

Clear Bowl and Goblet Stem

For the Bowl, the wax mold was attached to a clay reservoir. The weight of the wax was 192g, and by water displacement, equivalent to 571g of clear System 96 furnace pellets, and I used that glass in the mold.

The mold was 7″ x 7″, 60% Silica, 40% Plaster, and poured.

For the goblet Stem, the wax mold was again attached to a clay reservoir. The mold was 4.5″ x 5″, poured into a plastic pineapple container. The wax weighed 89g, and was equivalent to 270g of furnace pellets, for the casting, I used 275 clear cullet, and 20g powder (Colour RW HP229).

Both molds were poured and steamed on December 1st, and Firing started on December 1st in Kiln #4 on the following schedule:

1. 3:00 – 150
2. 15:00 @ 150
3. 22:00 – 515
4. 25:00 – 600
5. 25:01 – 875
6. 30:00 @ 875
7: 30:01 – 515
8. 38:01 @ 515
9. 55:01 – 400
10. 68:00 – 50

More pictures are available here:

Bowl and goblet stem

The goblet stem was picked up in the hotshop on December 9th, it was sent up to 515C over the course of 5 hours, then soaked for one hour, then sent up to 560C before being picked up and attached to a bubble and re-annealed on a normal annealing schedule for blown work in our studio.

Star Anise Bowl V1

Star Anise Bowl V1

The mold for this bowl was an open-faced, lost wax plaster silica hand-built mold. I made silica molds of real star anise, and took wax impressions from those molds and attached them to a blank wax bowl. The wax was approximately 2.5″ X 5″. After the mold was built and steamed, there were quite a few really bad undercuts, where the plaster had filled in between the anise and the bowl, so I cleaned those up as best I could. The mold was approximately 2″ thick throughout. The mold was built on September 28th, and Steamed on October 3rd, 2008.

On October 5th, I packed the mold with System 96 powdered glass in the following colours:
1. Light Amber 5 clear : 2 colour
2. Gold Brown – 8 clear : 2 colour
3. Black Transparent – 5 clear : 2 colour

The mold was fired on October 6th, with the following pate-de-verre fusing schedule:

1 hour to 100°C,
6 hours @ 100°C,
11 hours to 515°C,
13 hours to 720°C,
18 hours @ 720°C,
18.01 hours to 550°C,
25 hours to @ 550°C,
39 hours to 400°C,
46 hours to 50°
Star Anise #1

More details and pictures are available in the attached Picasa album.

I will re-make this bowl, as during the firing, the pate-de-verre slumped and pulled away from the edges of the mold, making the upper edge of the bowl rough and fragile. Also, a lot of plaster was fused into the glass, and is impossible to remove.