Making of Songs of Paradise (Lost)
The making of the Huia involved building the form in Plasterline (an oiled clay that doesn’t dry and is therefore reworkable / reusable). Then a multiple-piece mold was made using silicon and plaster. This was to enable the casting out of this, of a hollow wax form, that would then be encased in ceramic shell material - see the making of Unwitting Collusion pieces for the ceramic shell-making steps.
Stage 1
Wire, hobby mesh, thin aluminium sheet, Plasterline clay started the form of the Huia, based upon images in books and online, plus photos taken in the Auckland Museum archive of specimens - thankyou to the Museum people.
Stage 2
The clay was sculptured, and the bird arranged on a prepared branch, in wire and wax..
Stage 3
The silicon parts of the mold were built up prior to being encased in multiple pieces of the plaster mold material.
Stage 4
The object has some undercut details so both the silicon and plaster parts of the mold are separate so they can be taken apart, once the wax is poured into it has set. This is a hollow-cast piece, so the mold needs an inner refractory core that will keep the inside of the bronze object hollow.
Stage 5
Wax of slightly different temperatures is poured in, then poured out after rotating the mold. This enables a coating on the inside, of wax so that the bronze object will be hollow when cast. The stainless steel screws visible in the second image will hold investment material (plaster and brick-dust poured in through a hole left underneath the bird’s body), and the screws will be held in place in the ceramic shell to come. The branch and legs parts are shown with vents / risers attached - it will be cast upside down and the vents allow air to escxape during the pour. The body and the branch / legs are to be cast separately, as the two masses of bronze would not work well in the a combined mold. The last image shows the Huia with the sprue / funnel (note that the bronze will be delivered into two entries), and vents that will take the air back up to the edge of the sprue.
Stage 6
First coat of the ceramic shell build up is zircon sand which is fine, and will allow for fine detail and it will be the first surface to withstand the thermal shock of molten bronze. Subsequent coatings involve the ceramic materials added to the mold.
Stage 7
Huia fresh out of its molds, arranged together for a test for fit. Note that the stainless steel screws have been removed, and (though not visible here) the inside plaster / brick-dust material has been scooped out.
Stage 8
This is the ‘museum box’ that the Huia is to be presented in.
