Bullseye Glass Mold #8974 Mini Cone Bowl 5.25"

The Bullseye Glass Mold #8974 Mini Cone Bowl is a steep-sided cone slumping form that shapes a pre-cut fusible glass blank into a small cone bowl. The mold outer dimensions are 5.3 inches by 1.5 inches (13.33 by 3.81 cm), which is the footprint to check against your kiln shelf. Cut a glass blank to about 4.5 inches, center it over the form, and fire slowly so the glass softens and settles into the steep cone under gravity.

The form is slipcast from a specially formulated clay body by Creative Ceramics in Europe and imported and sold by Bullseye Glass. The surface is exceptionally smooth and accepts kiln wash uniformly, which promotes clean release. Because of the steep cone geometry, Bullseye recommends re-priming the forming surface every two to three firings. These molds are handmade and vary slightly in size, so measure before cutting your glass blank.

What does this mold make?
It shapes a flat glass blank into a steep-sided mini cone bowl. Cut the glass to about 4.5 inches (11.4 cm) and the mold forms it into the cone shape during the slump firing.

How do I set up this mold in the kiln?
Elevate the mold on 2 inch (5 cm) posts and center it in the kiln to promote even heating, slumping, and cooling. Level both the mold and the glass blank before firing so the glass settles evenly into the cone.

What COE glass can I use?
Any COE. Ceramic slumping forms are COE agnostic, so the same mold works with COE90, COE96, or other fusible glass. Match your firing schedule and anneal temperature to the glass you are using.

How often should I re-prime the forming surface?
More often than a shallow form. Because of the steep cone geometry, Bullseye recommends re-priming the forming surface every two to three firings. A thin, even coat of kiln wash applied and fully dried before each session helps ensure clean release.

Specifications

• SKU: 176382
• Manufacturer: Bullseye Glass (made by Creative Ceramics, Europe; store model BG8974, design #8974, item 008974-MOLD-M-EACH)
• Makes: 1 steep-sided cone bowl
• Glass cut size: about 4.5 inches (11.4 cm)
• Mold outer dimensions: 5.3 inches x 1.5 inches (13.33 x 3.81 cm)
• Kiln setup: elevate on 2 inch (5 cm) posts, centered and level
• Material: slipcast ceramic slumping form, reusable
• Glass: any COE (COE agnostic)

Working Notes

These are guidelines, not guarantees. Every kiln fires a little differently, so test a small piece first when the result matters and follow a slumping schedule suited to your glass and kiln.

• Prime the forming surface with a kiln wash or a boron nitride primer such as ZYP Boron Nitride Mold Primer, and let it dry completely before placing glass on the mold.
• Because of the steep cone geometry, re-prime the forming surface every two to three firings, not only when the surface looks worn.
• Elevate the mold on 2 inch (5 cm) posts and center it in the kiln. Level the mold and the glass blank so the glass settles evenly into the cone during firing.
• Cut your glass blank to about 4.5 inches (11.4 cm), working inside the top rim for more uniform results. These molds are handmade and vary slightly in size, so measure the mold before cutting glass.
• The mold is COE agnostic. Use a slumping schedule matched to your glass and adjust the anneal soak temperature for your COE.
• Steep molds heat unevenly, so visually confirm that the glass has fully settled into the cone before moving to the anneal step. Let the kiln cool fully before removing the finished piece.

Suggested Slumping Schedule

This is a suggested starting schedule based on Bullseye's published guidance for steep cone slumps, not a guarantee. Every kiln fires differently. Visually confirm the slump is complete and adjust the schedule for your glass and kiln. Test a small piece first.

*Segment 3 is the anneal soak. Adjust this temperature for your glass: about 900 F for COE90, about 950 F for COE96. Because of the steep geometry, visually confirm the glass has fully settled before ending the segment 2 hold, and extend that hold if needed. Follow Bullseye's published Cone Bowl tip sheet for additional guidance.

Helpful downloads: Suggested Slumping Schedules from Bullseye Glass (PDF)

Description updated: July 6, 2026

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