01.
Choose the Stringer
Unlike the .5mm Stringer Bowl, I decided to use transparent stringer selected from a tube of assorted colors.
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).
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.
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.
05.
Fused
But after fusing, it turns out that extra lengths of stringer wasn’t a problem. The fused glass is perfectly circular.
06.
Stringer Not Long Enough
Instead of having stringer that extends too far, the clear glass has flowed beyond the 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
BONUS
The Accidental Fuser at Work
Grinding with the 80 grit.
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.