This glass fusing project tutorial is all about stacking glass and making a Japanese bowl. The technique is not hard but results in a beautiful piece.
The video tutorial includes the design, materials, and equipment information, as well as cutting the odd-shaped glass, plus coldworking with a grinder and sandblasting. Finally, I cover the full fusing, fire polishing, and glass slumping.
Project Information
In the YouTube video, you will find links to related videos, a chapter list with time stamps, and links to more resources.
Just as a reminder, the glass I use is Bullseye 90 COE. On the shelf for full fusing, I use Thinfire fiber paper. When fire polishing on my shelf, and slumping in moulds, I spray with boron nitride mould release.
The stacking technique I use is not new. You will find it used in fused glass pieces quite a lot. It’s the reverse colours on each side that makes this different.
The final dimensions of the bowl are 14 cm x 14 cm (5.5 inches), with a depth of about 5 cm (2 inches). The glass fusing mould used is a deep Japanese bowl. Because the sides are a little steep, you will need to consider this in the slump. You will likely need a long hold, and possibly a slightly higher temperature to get the slump to the bottom.
The materials are Lavendar (0142), Dusty Lilac (0303), and Opaque White (0013). The large main pieces are 2 mm. The small pieces for the stacks are 3 mm, though 2 mm can also be used. In the end, I wasn’t sure about my colour choice as it lacked contrast between the two main colours. I believe that a good contrast between colours will produce a better result, though this is a very personal choice.
The main pieces of glass were first cut with a normal glass cutter, but they then needed some coldworking to smooth the curves. This was done on a Glastar Glass Grinder.
The pieces for stacking were done freehand to approximate the size needed. The white was cut a little smaller for stacking.
As mentioned in the video, one side was stacked and fully fused first. This was then turned over, stacked again, and again fully fused. The firing schedule for this is below. Both fusings used the same schedule.
After fusing, as expected, the sides were bumpy and this also needed some coldworking to refine the curves. I did this on my second-hand flat lap. This could also be done using a small glass grinder, diamond pads, or even wet and dry sandpaper. Finally, I sandblasted the piece to tidy up the grinding and to remove some devitrification. This ensured a good fire polish finish.
You will see in the video that even though you might expect the mould to be even on all sides, it wasn’t. You need to be aware of this. Orientation of the piece may be critical.
The final slump went well, without any major issues.
If you have any questions please ask in the comments section on YouTube.
Full Fuse Firing Schedule
- #1 – 222 C (432 F) up to 535 C (995 F), hold 90 minutes
- #2 – Full up to 805 C (1480 F), hold 10 minutes
- #3 – Full down to 482 C (900 F), hold 90 minutes
- #4 – 65 C ( 149 F) down to 425 C (797 F), no hold
- #5 – 132 C ( 270 F) down to 371 C (700 F), no hold
Fire Polish Firing Schedule
- #1 – 222 C (432 F) up to 535 C (995 F), hold 60 minutes
- #2 – Full up to 720 C (1328 F), hold 10 minutes
- #3 – Full down to 482 C (900 F), hold 60 minutes
- #4 – 65 C ( 149 F) down to 425 C (797 F), no hold
- #5 – 132 C ( 270 F) down to 371 C (700 F), no hold
Slump Firing Schedule
- #1 – 167 C (333 F) up to 640 C (1157 F), hold 20 minutes
- #2 – Full down to 482 C (900 F), hold 60 minutes
- #3 – 65 C ( 149 F) down to 425 C (797 F), no hold
- #4 – 132 C ( 270 F) down to 371 C (700 F), no hold