Bullseye Glass Mold #8740, Lamp Bender Conic 12.2"

The Bullseye Glass Mold 8740, Lamp Bender Conic 12.2 inch, is a slumping form designed to drape a flat or fused glass blank into a cone shape. A pre-cut blank is placed over the conic form, then fired until the glass softens and sags under gravity to match the form, producing a finished cone suited to lamp shades and similar work.

The mold 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. Outer dimensions for confirming kiln fit are 12.2 by 10.4 by 3.8 inches (31 by 27 by 10 cm). Because these forms are handmade, dimensions vary slightly from piece to piece, so measure the mold before cutting glass to fit.

What does the Lamp Bender Conic 12.2 mold make?
It drapes a glass blank over a conic form, producing a cone-shaped piece suited to lamp shades and similar work. Place a pre-cut or pre-fused glass blank over the form and fire until the glass conforms to the shape.

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

How do I prepare the mold?
Coat the forming surface with a kiln wash such as Hotline Primo Primer and let it dry completely before placing glass on the mold. Bullseye's clay body accepts kiln wash uniformly. A boron nitride primer is also an option if you prefer it.

How do I confirm the slump is complete?
Watch through the peephole as the kiln climbs. The glass should gradually soften and conform to the conic form. Use the suggested schedule as a starting point and adjust for your specific kiln and glass.

Specifications

• SKU: 164851
• Manufacturer: Bullseye Glass (made by Creative Ceramics; design number 8740; item 008740-MOLD-M-EACH; store code BG8740)
• Mold type: Slumping form, conic (Lamp Bender series)
• Outer dimensions: 12.2 x 10.4 x 3.8 in (31 x 27 x 10 cm)
• Material: Slipcast ceramic, specially formulated clay body, reusable
• Glass: Any COE (COE agnostic)
• Note: Molds are handmade and vary slightly in size. Measure before cutting glass.

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.

• Coat the forming surface with kiln wash and let it dry fully before placing glass on the mold. You may also use a boron nitride mold primer such as ZYP Boron Nitride Mold Primer.
• Place a pre-cut or pre-fused glass blank over the conic form. This is a slumping form, not a frit casting mold, so use sheet glass or a fused blank rather than loose frit.
• The mold is COE agnostic. Use a slumping schedule matched to your glass, adjusting the anneal soak temperature for your COE.
• Watch the firing through the peephole and confirm the glass has fully conformed to the form before starting the cool-down sequence.
• Let the kiln cool fully before removing the slumped piece. Recoat the mold with kiln wash as needed between firings.

Bullseye Suggested Slumping Schedule

Based on slumping 6mm pieces in a Paragon GL24. This is a suggested starting schedule, not a guarantee. Every kiln fires differently and glass styles vary in viscosity. Visually confirm the slump during firing and adjust the schedule for your glass and kiln.

AFAP means as fast as possible. Segment 4 lets the kiln cool at its natural rate, door closed, to room temperature.

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

Description updated: July 6, 2026

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