The Process of Lost-Wax Casting

Firstly I make a wax model of the Glass Art Object I wish to create. I usually start with a solid block and carve into it. I spend a lot of time working on the surface of the wax getting exactly as I want the glass to end up. Each mark and texture will show in the final work.

Around the wax model I hand build a mould in layers using dental plaster, silica flour and fiberglass matting. The walls maybe up to 70mm in thickness and consist of 7 layers, depending on the mass of glass to go inside.

The wax is then steamed out of the mould to be re-used another time.

The mould is now propped up in the kiln with the opening at the top. The lead-crystal is calculated per volume to the wax model and packed in a terracotta plant pot. This is placed above the mould so that when the glass heats it pours through the opening in the bottom of the pot and into the mould. The placement of the colour in the pot determines where it will end up in the final sculpture. I often add up to four colours in the larger works.

The mould stays in the kiln for a minimum of five days and a maximum of three weeks depending on the volume of the work. This is because it must be heated slowly to ensure the mould is completely dry before the glass starts to pour, and cooled slowly to ensure the glass is annealed correctly.

When the glass is sufficiently cooled to room temperature the mould is broken apart carefully to reveal the glass.

The Glass Art Object still needs a lot of work in the form of sawing, grinding and polishing to give the glass sculpture it?s maximum transparent qualities. There is specific machinery designed for this using diamond pads for polishing and diamonds blades for cutting.