A common question from new recycled glass artists is “How do I make glass donuts and rings?” Happily, I’m here to tell you.
Recycled bottle glass donuts are made from the neck of bottles, cut into slices, typically with a tile saw. There are some easy things to remember for donut success:
1. Taller isn’t always better.
Here are two cobalt rings, one about 3/8″ tall, and the other about 1″ tall. Fused in the same batch, using the same firing schedule:
You can see the shorter donut has rounded nicely, the taller one has rounded, but the top has slumped over and inside, making the hole smaller and the inside slightly lumpy. A good optimum height for donuts is 3/8″ to 1/2″ tall.
2. Smooth cuts matter.
Not to say that smooth cuts are better, but you should be aware of what will happen when you fuse donuts that are cut a little differently.
3. Not all colors fuse the same. But they are pretty darn close.
Here is a veritable rainbow of color donuts, all about the same height, all fused with the same firing schedule.
You can see the clear bottles didn’t melt quite as much, and the light blue also didn’t smooth out wonderfully. If one of your colors is giving you problems, try a different bottle of the same color glass, preferably a different brand. Not all bottles are created equally, the issue may be with the glass!
Recycled Bottle Glass Rings
Rings are made by fusing thinly cut slices from the body of a bottle. After a question from a wonderful reader, I decided to do some experimenting to find the optimum slice height and bottle thickness for predictable fused glass rings.
What I found:
1. Most wine bottles are very close to 1/8″ thick measured through the wall of the bottle. To measure, cut the top off of your bottle and measure the glass from the inside of the bottle to the outside.
2. Most champagne bottles are 1/4″ thick measured through the wall of the bottle. This becomes important later.
3. It’s really challenging to cut smooth, regular rings from a bottle, any bottle.
Using several different colors of bottles, I tried to cut comparable height of rings from each bottle. I succeeded, more or less, some are more and some are less. The conclusions are the same however:
The thinnest ring fused the most smoothly, but it is quite fragile. The right hand most ring folded over and didn’t fuse in a perfectly round circle, but it is the most sturdy of the 3.
Again, the thinnest ring fused the most smoothly, but is quite fragile, while the thicker ring folded over and fused off round.
Both of these cobalt wine bottle rings folded over and fused out of round, but they are kind of glossy, so may be useable for some applications. Both are quite fragile.
These rings are from a sparkling chardonnay, bottled in a champagne style bottle. As you can see, the thinnest fused the most smoothly (it had a crack that I didn’t see in it). The right hand most ring is the sturdiest. Note that even though the thinnest ring is fragile, it is still TWICE as thick as the thinnest wine bottle ring.
Once again, the thinnest ring is the smoothest.
My conclusions and recommendations from this series of experiments are:
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For best results, use smoothly sawn donuts that measure between 3/8″ and 3/4″ tall
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For rings, measure the thickness of the bottle and cut the rings so the height is 1.5x the width.
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Use a full fuse firing schedule.
Fused Bottle Glass Donuts – Part 2
Fusing bottle glass donuts can seem like a very easy process, until you run into a problem and can’t figure out where things went wrong. For example, if your donuts have a ring of devit on the inner edge, how did that get there? and how to fix it? I ran a little test to see how the glass moves when donuts are fused. This is an easy test, and one I would suggest for everyone to try as all kilns fire differently and this will give you valuable information about your kilns firing process.
Begin with clear glass donuts, try to use ones that are the roughly the same height and width.
Clear bottle glass donuts
Using fusible glass paint, I’ve painted the inside of one donut, the outside of the next, the top cut edge of the third, and the bottom cut edge of the fourth:
Paint the different sides of the donuts
Now fire to a full fuse using your fusing schedule, or mine.
donuts after firing
You can see the inside of the donut has ended up mainly on the bottom of the fused donut. The outside surface stays mostly on the outside of the fused donut. The top cut edge gets smaller as it slides into the center of the donut, and the bottom edge stays pretty much where it started.
I suggest keeping these fused donuts handy to compare fusing issues to and help trouble shoot. You can also use this information to embellish your fused glass donuts. I tried some other combinations that you may find interesting:
Mica – when painting mica onto fused items, it’s works best on an etched or slightly rough surface. I tried using the rough sawed edge just to see how well the mica fused:
Cobalt donut with mica
The mica adhered well during the firing, and made an interesting ring around the top of the donut. The mica was trapped in the saw marks and is more visible there.
I also tried the same experiment with clear donuts, painting two clear donuts with gold and copper mica on the cut edges, and firing one gold side up and one gold side down.
The mica sticks better on the top edge, washing out somewhat on the bottom surface.
Ideally, mica works best on already fired donuts that are etched or tumbled, then painted with mica and fired to a slump temperature.
I also tried glass paint in different colors on the inside and outside of my donut:
I think this is an intriguing result that needs more practice and some tweaking.