Making a Geometric Design Fused Glass Chinese Bowl


This little fused glass bowl started out, in my head, as a very balanced and uniform geometric design, but ended up a lot more random. But I think that’s the beauty of glass art, you can just adapt to your design whims.

At least, to a point. I suppose the glass does dictate a little, but there is so much you can do with glass. More than you may realise.

Anyway, on to this bowl.

The Design

My basic idea was to create a very uniform and balanced geometric design. You know what I mean, left and right mirrored etc. But when I laid out the pieces, and yes I did cut them, the design was to uniform and ordered. So I threw that idea away and started just playing with pieces of glass until I found something that worked for me.

As usual, all the glass I use is Bullseye 90 COE and all glass in this project is 3mm thick. Keep this in mind when designing your fusing schedules.

Chinese Bowl

In this photo you can see what I ended up with. Even the colours were a bit random, it all depended on what I had in scrap.

Don’t worry about the pieces not fitting perfectly, I did refine that to make sure I had tighter edges before fusing.

Cutting and Shaping

I know what your asking. How did I get all those angles right. Well, I did place the mold on a sheet of paper, drew around that, and then drew random lines across it to create a design. I then decided on what colour goes in each section, somewhat driven by the shape and size of my scrap pieces.

Sorry, didn’t take a photo of the design on paper and I threw it out without thinking. Even I’m a bit random at times.

Chinese Bowl

Anyway, I then placed each piece of scrap on the design and using a marker drew the lines for cutting. I cut each piece in turn, then placed it on the design to make sure it fit. If needed, I used a grinder to refine the edges.

In this next photo you can see it all laid up, on Thinfire kiln paper, and capped with a piece of clear 3mm, in the kiln ready to full fuse. You can see that I refined all the edges to make sure it all fit together nicely.

I wasn’t worried about the uneven outside edges as I intended to grind the final edge to square it up for the slump.

All Fused Up

Chinese Bowl

So here it is, all fused up. As usual, you will find the firing schedules I used for this project, below.

This is before any cold work on the edges of the piece. Those ragged edges of the glass before fusing have resolved themselves in the full fuse to produce a nice rounded edge.

This is the top of the piece, the side capped with clear, and you can see that all those nice geometric lines remain straight and crisp. Without the clear capping they would most likely have wandered a little and would not look anywhere near as nice.

Chinese Bowl

Here you can see the bottom of the piece.

Because this was in contact with the Thinfire paper and shelf, the lines have also remained nice and straight. The texture is from the Thinfire paper, as I am sure you are aware. But that will resolve itself out in the slump.

Cold Working

But, of course, I really wanted a square edge on this piece. Don’t ask why. I’m an artist and even we don’t always know why we do things. That’s what art is all about. It’s more a feeling than a science. I ramble, I know.

So off to the grinder and I ground that edge into a square edge.

Chinese Bowl

You can see that in this photo. Yes, there is a slight angle on the edge, but after the bowl has been slumped into the mold, it won’t be obvious at all.

For grinding I use a Glastar Super Star II grinder and a large flat lap. You can read a lot more about how I cold work in my post, My Station for Cold Working Fused Glass.

You will see a little later that my decision to grind the edge was not the best, though it was more about how I executed it than the decision itself.

Slumping in Mold

Now to the slumping.

Fused Glass Bowl on Mold

In this photo you can see the prepared piece setup on the mold. The mold has been prepared with boron nitride spray. I just find it a lot easier to apply, very little clean up and a far better result.

I find that this mold needs to be watched. One piece I made was slumped too long and the sides started to distort a bit, probably because of the steeper sides. Anyway, once I believe it has touched bottom, I finish the slump process and leave to anneal and cool.

Finished Bowl

So below you will see the finished piece. It isn’t bad, but there is a problem that I wasn’t very happy about.

After grinding the edges, I left them unfinished, hoping I would get a nice frosted finish after the slump. But they actually polished more than I expected, which then highlighted some of the final grinding marks which then made it look unfinished. In hindsight, I would now leave the edges rounded, and only cold work if there was an issue.

Fused Glass Chinese Bowl

In Summary

So, if your going to have a go at this, and I hope you do, this should help with some of the decision making regards design, colours and final finish. Of course, you don’t have to make a Chinese bowl shape. You could make any shape, including a flat cheeseboard or something.

Hope you have fun and please comment or ask questions. Always happy to help.

Firing Schedule

Please be aware that all kilns fire differently and this schedule may not produce the same results in your kiln.

Full Fuse – Geometric Chinese Bowl

SegmentRate ºC (ºF) /hrTarget ºC F)Hold (mns)
1. Release220 (428)535 (995)30
2. Bubble220 (428)620 (1148)30
3. Bubble38 (100)677 (1250)30
4. ProcessFull800 (1472)5
5. AnnealFull482 (900)60
6. Cool83 (181)375 (707)0

Slump – Geometric Chinese Bowl

SegmentRate ºC (ºF) /hrTarget ºC F)Hold (mns)
1. Process167 (333)630 (1166)10
2. AnnealFull482 (900)60
3. Cool56 (133)375 (707)30

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top