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01.

Choose the Stringer

Unlike the .5mm Stringer Bowl, I decided to use transparent stringer selected from a tube of assorted colors.

2mm Stringer
02.

Cut a Circle

Using the Bohle Silberschnitt circle cutter, I cut an 8 inch circle from transparent Tekta glass, aiming for approximately the same size as the .5mm stringer bowl, a nice size for candy or maybe guacamole. Actually I cut two transparent circles that will stack in order to achieve the right thickness (6 mm).

Score A Circle
Break the Circle Out
03.

Glue Them Down

For this bowl I wanted to be as accurate as possible with the stringer before fusing. I glued each stringer in place (the little squeeze bottle at left) then cut them right at the edge of the circle with the tile nippers at right.

Stringers Glued to Transparent Circle
04.

In the Kiln

But as you can see with the stringer side placed down on the ThinFire shelf paper, I didn’t clip the shortest pieces of stringer at the front and back. That’s because they pulled loose from the transparent circle when I tried to nip them. So I left them too long and decided I’d coldwork them off after fusing.

Loaded in the Kiln for Fusing
05.

Fused

But after fusing, it turns out that extra lengths of stringer wasn’t a problem. The fused glass is perfectly circular.

Fused
06.

Stringer Not Long Enough

Instead of having stringer that extends too far, the clear glass has flowed beyond the stringer.

Fused Stringer
07.

Scoring the Fused Glass

Since I don’t want a border of clear glass at the rim of the bowl, I decided to grind it off.  I used the circle cutter again and scored a line that cut through the stringer all around. Below is a closeup of the new score.

Scoring the Fused Glass
Closeup of Score
08.

Grind It

I’ve never tried to break a very thin edge from a 6mm thick piece of glass and doubt very much that I’d manage to do it without breaking the entire piece. So I decided to grind it off, as I did with the first bowl. Below is a closeup of the grinding in progress.

Glass Grinder
Closeup of Glass Grinder
09.

Ground Edge

Although the clear edge has now been ground off, the grinder has left deep scratches. Although I don’t have a picture of the next step, I used loose grit (80, then 120, and finally 400) to create a matte finish that I knew would fire polish to a gloss when I slumped it.

Ground Edge
10.

Ready to Slump

Once again I’ve chosen the Large Cone Bowl mold (8975). Here’s the fused glass centered on the mold and ready to be fired again.

Ready to Slump
11.

Needling

Unfortunately I don’t have a picture of the slumped bowl in the mold because I always forget to photograph it in my excitement to take it out of the kiln. Although you can see that the edge did indeed become glossy, I also got one tiny bit of needling (where the glass sticks to the mold as it slides down). The slump came out even and though this was the only flaw, I couldn’t leave it. But grinding off just the needling would leave me with a little section of matte finish on an otherwise glossy edge. That was unacceptable.

Needling
12.

Lemonade

I decided to grind off the entire edge and make the rim flat. This technique is something I’d wanted to try for some time. So it’s lemonade from lemons for me. It will also give me a different final shape to this bowl, which is also fun. Using a figure 8 motion, I slid the bowl through various grit slurries on top of a pane of glass.

Loose Grit Coldworking
13.

80 Grit Silicon Carbide

The most coarse grit is used to remove material. After the 80 grit, I’ve ground away the beveled rim to a flat rim. 

Result from 80 Grit
14.

400 Grit Silicon Carbide

I’ll skip the photo of the 120 grit and go right to the 400. At this point the matte finish is as smooth as a baby’s bottom. But the thin edge at the outside of the rim is fracturing as I work the bowl in the figure 8 motion. At this point, I’m done with the loose grit so I can avoid the little fractures.

Result from 400 Grit
15.

Diamond Hand Lap Pads

Once again I used various stages of grit, from 120 through 400, but with diamond pads. Using the hand lapping technique, I can finely control just how much of a bevel I give to the outside edge of the flat rim in order to remove the little fractures.

Hand Lap the Bevel with Diamond Pads
16.

The Finished Rim

Though I hadn’t planned on this type of rim at the outset, I’m super pleased with the end result. It’s entirely smooth and matte, and you can still see the stringer through it. I can’t stop running my finger over the surface.

The Finished Rim
Results

Final Result

I can’t believe how much I like this flat and ultra smooth matte finish. Though it entailed four or five hours of coldworking, it was most definitely worth it.

Final Result
BONUS

The Accidental Fuser at Work

Grinding with the 80 grit.

With Grapes

FULL FUSING SCHEDULE (RUN TIME 12:55)*

SEGMENT RATE (deg F / hour) TEMPERATURE (F) HOLD (hours:minutes)
1 200 1000 :15
2 300 1225 :30
3 350 1470 :20
4 AFAP 950 2:00
5 100 700 OFF

SLUMP FUSING SCHEDULE (RUN TIME 9:47)*

SEGMENT RATE (deg F / hour) TEMPERATURE (F) HOLD (hours:minutes)
1 300 1200 :30
2 300 1225 1:30
3 AFAP 900 1:00
4 100 700 OFF

* The firing schedules may be designed for other projects that were fired with this one. Everything was fired in a Paragon GL-22AD.