01.
Stringers and Spacers
I’ve already cut the clear Tekta glass (3mm thick, 10 x 8 inches). It’s sitting on a set of four small ceramic dam pieces, elevating it from my gray cutting mat just to make it easier to pick up later. For the green lines I used Spring Green Transparent 2mm stringer (all of the glass in this project is made by Bullseye). For the red, I used Sunset Coral Transparent 2mm stringer. For the yellow, Medium Amber Transparent 2mm stringer.
02.
Close-up of Spacers
The small pieces of black glass are used as spacers between the stringers. By standing them on edge, two together, the 3mm thickness of the black glass translates into a consistent 6mm space between the stringers. Everything is glued down with GlasTac Gel.
03.
Two Sides of the Sandwich
Two, identical layups are ready, side by side. Both are required for this project, as you’ll see in few seconds.
04.
Final View Before Tack Fusing
Just wanted to show an end-on view of half the project, ready to be tack fused.
05.
Into the Kiln
The two halves of the project (along with another that is mostly green) are loaded onto a mullite kiln shelf with ThinFire paper as a separator between shelf and glass. The point of the tack fuse is to bring the glass up to a temperature where the pieces tack together but don’t move, let alone melt or fuse.
06.
Tack Fused
The piece has successfully tack-fused, the stringers still in place.
07.
Tack Fuse Close-up
There’s just the slightest bit of movement as the little black spacers lean one way or another. The ends of the red stringer droop over the side of the clear Tekta base. Neither makes a difference to the project.
08.
Make It Square
The reason the size of the clear base glass was 10×8 inches is that I knew I’d need to cut off the spacers.
09.
Nice and Neat
Tack fused glass acts just like a single piece of glass when it comes to cutting. I scored the glass, then used running pliers, and the ends broke off straight and clean. This part always amazes me.
10.
The Ends
These are the pieces that were cut off, in case you were curious.
11.
Bubble Sandwich
Now we begin to see the form of the end result. I take one of the identical tack fused pieces, flip it over, rotate it 90 degrees, then place it on top of the other tack fused piece. When they are fused, the little empty squares created by the red stringer will trap air as the top and bottom come together.
12.
Place the Two Halves into the Kiln
At the back left are the two halves ready to be fully fused.
13.
Fully Fused
From here, that looks like a flat and fully fused piece of glass.
14.
Ready to Slump
Now that the glass is fully fused and flat, we’re ready to give it a final form. From the start this project has been designed for the Square Slumper mold, No. 8635 (8.5 x 8.5 x 1.5 inches).
15.
Third Time in the Kiln
At the back left is the fused glass, centered on the slump mold, balanced at just the four corners.
16.
Slumped
For once I’ve remembered to photograph the slumped pieces in the kiln! That’s the end of this project.
Results
Final Result
Though I’ve done the bubble plate project before, I’m still amazed at the end result. It’s a real puzzler for some people when they first see it. I think that’s part of my delight.
Close-up One
Couldn’t resist a couple of close-ups.
Close-up Two
Last one, I promise.
TACK FUSING SCHEDULE (RUN TIME 8:54)*
| SEGMENT | RATE (deg F / hour) | TEMPERATURE (F) | HOLD (hours:minutes) |
| 1 | 300 | 1000 | :00 |
| 2 | 225 | 1225 | :30 |
| 3 | AFAP | 1400 | :00 |
| 4 | AFAP | 950 | 1:00 |
| 5 | 100 | 725 | OFF |
FULL FUSING SCHEDULE (RUN TIME 13:34)*
| SEGMENT | RATE (deg F / hour) | TEMPERATURE (F) | HOLD (hours:minutes) |
| 1 | 150 | 1000 | :15 |
| 2 | 225 | 1225 | :30 |
| 3 | AFAP | 1475 | :20 |
| 4 | AFAP | 950 | 1:30 |
| 5 | 100 | 725 | OFF |
SLUMP FUSING SCHEDULE (RUN TIME 12:34, 17.1 kWH)*
| SEGMENT | RATE (deg F / hour) | TEMPERATURE (F) | HOLD (hours:minutes) |
| 1 | 150 | 1000 | :00 |
| 2 | 100 | 1200 | 0 |
| 3 | AFAP | 950 | 1:30 |
| 4 | 100 | 725 | OFF |
* The firing schedules may be designed for other projects that were fired with this one. Everything was fired in a Paragon GL-22AD.