Oh, it depends on so many things .. color, thickness of piece, the kiln, the controller, the thermocouple, the distance of the glass from the elements …
I generally fire at 1300 to 1325 for 1 minute for a tack fuse, but that’s just me and my kilns.
Try a few test pieces and see what you like. Embrace failure.
You could try these:
1) Read the “Bubble Squeeze” section in the “Firing Schedule Tutorial” under “What’s New?” at the top left side of your screen.
2) Use “Reed Glass” (Bullseye) or “Cord Glass” (Uroboros) as the clear cap. The ridges allow the air to escape as the piece fires
3) Place small clear beeds or large clear frit around the edg…[Read more]
Those are for firing glased pottery. They come in all sizes and shapes — straight, square, triangular. The metal points (facing up) keep the bottom of the piece off the kiln shelf so the glaze doesn’t fasten the piece to the shelf. Fairly useless for glass firing.