Firing schedules *F
FAHRENHEIT Celsius
Here’s a freebie from our Foundations Class before you look at schedules. If you understand the image below you are more than ready to fire your own kiln! If you have questions, call the studio or consider joining the next Foundations Class (it’s not just for beginners!).
NOTE: The following schedules and charts were built specifically for Bullseye glass and follow *F.
Helios basic Firing Schedules
Click each image for a downloadable PDF.
Additional firing schedule resources
For thick pieces (1/2in or larger) or varying thickness (textured) pieces:
Bullseye’s Thick Slabs Annealing chart - This chart gives you your anneal and cooling segments for thick or textured projects. It replaces the last few segments in any above schedule starting at the anneal time (the segment that holds at 900*F)
Using a different COE glass?
OceanSide has resources online for COE96.
Glass With A Past has resources for bottle glass and crystal.
Bullseye suggests raising all ~ COE90 temps by ~ 100*F for float glass (aka window glass).
Tips to adjust schedules to your specific firing needs…
ADD A PINK HOLD: Ramp 100*F to 1225*F and hold for 2:00hr. Does your glass need a pink hold? Pinks are needy like that. Don’t forget to add this segment in. And, use it as a replacement for the bubble squeeze segment! Two birds, one stone!
ADD A EXPEL MOISTURE SEGMENT: Ramp ❗️ to 200*F and hold for :20min. Add this segment as your first segment with a ramp that’s appropriate for the thickness to your solid glass pieces. It lets any water turn to vapor gently, without boiling (boiling water can disturb powder if your doing a freeze & fuse). You’ll want to vent your kiln about a half inch just during this segment, too.
ADD A EXPEL BINDERS/GLUE SEGMENT: Ramp ❗️ to 450*F and hold for :20min. Add this segment as your first segment with a ramp that’s appropriate for the thickness to your solid glass pieces. You’ll want to vent your kiln about a half inch just during this segment, too.
ADD A DOUBLE BUBBLE SQUEEZE SEGMENT: Add as segment 3 - Ramp 50*F to 1275*F and hold for :45min. Need to avoid bubbles? Either hold that bubble squeeze segment longer (segment 2), or add a second bubble squeeze in at a slightly hotter temp!
ADD A PRE-ANNEAL HOLD SEGMENT: Add as segment 4 - Ramp 9999 to 1490*F and hold for :20min. If you are doing a higher than 1525*F firing that may have produced bubbles, or a pot/mesh melt that could leave glass pour remnant pillars, add this segment in to let the extra glass settle or popped bubbles heal. It’ll give you a perfectly flat final look!
MORE TIPS…
Pay attention to the thickness of the solid pieces! Adjust your ramp speed going up and coming down to match the thickness of the solid glass. Check the Bullseye Thick Slabs Annealing chart if you’re unsure about a large piece.
Know your kiln! They’re like people. Some run a bit hotter than average, so you back off a little bit. Some are a bit cooler and need more time and attention to warm up. So, adjust your top temps in the process segment (tack, soft, full) according to your own kiln tests.
Size does matter…it limits the glass’s distance away from elements. Larger than average means a width above 10in across. Pieces that are so large on the kiln shelf that they are near the side elements (within 4in) require dams to buffer the heat from the elements and lower ramp speeds on the initial heating and annealing section.
Does you piece need to level out, settle in, squish down, or otherwise compact itself? Give it looots of time. Think about lengthening the hold on your processing segment.
Are you trying to pick-up lots of textures? You may want to go a little hotter or a little longer on your processing segment. Avoiding textures? Go cooler or shorter hold on that processing segment, my friend.