Most of our work is produced using the ‘lost wax method’ a process that is thousand of years old. Put simply it involves ‘investing’ the wax pattern, melting out the wax to form a mould and pouring the metal into the cavity.

Sounds simple?

Here are some of the steps commonly involved in our studio process: simply click on the + sign to expand our photo gallery

Clay is one of the most common mediums often supported by a metal armature

HVS denise2   HVS studio11   HVS col1

Once the piece is leather dry apply coats of a silicon rubber to form an elastic mould and a supporting mother mould

HVS rubber2   HVS toff shell rubber   HVS hand rubber

Using melted microcrystaline wax fill the mould to make a pattern resembling the original clay. This wax is often hollow to reduce the amount of bronze required.

HVS studio13   sprued waxes on table   studio2

Sprue the wax using a stronger spruing wax to add pouring cup, runners and risers. This provides a way of filling the shell with metal and allowing gasses to escape.

waxes on table   David spraying   wax hand

Invest the sprued wax by coating it with a ceramic shell. This is a high tech material and requires numerous coats of coloidal silica, zircon and calcined flint clay.

shell1   HVS toff shell rubber   Denise shelled on table

De-wax the shell using an electric kiln at temperature around 300ºC. Test and repair the shell if necessary as the expanding wax is capable of cracking the shell.

shell3   kiln loaded

Fire the shell in the kiln to 950ºC to ‘set’ the ceramic shell material.

shell filled   HVS gas furnace   HVS denise furnace

Melt the silicon bronze in the induction furnace to about 1150ºC.

Remove the shell from the kiln and the crucible from he furnace and pour the molten metal into the shell cavity.

Once the metal has solidified drop the still hot shell filled with metal into a metal container filled with water and crack off the shell. Then sandblast to remove the last of the shell.

crucible3      hammer and shell

Cut off the metal sprues and repair any defects. ‘chase’ the metal surface and finish with sanding and polishing tools

Sandblast the piece to provide a finished surface suitable for accepting patina chemicals. There are hundred of recipes available but the most common are ferric nitrate and cupric nitrate often preceded by liver of sulphur.

rough casts   HVS David4   HVS denise8

Once the patina has been applied treat with bees wax and buff and polish.

Mount the piece on the plinth, base or pedestal. We tend to use local Toowoomba black and pink granites and local sandstones for much of our finished sculptures.

SydneyNY2015_009     HVS toff1    SydneyNY2015_008     HVS 16109:2:2