Casting - Waxing & Build Up
Waxing from the Mould
From the completed moulds wax replicas are produced. This is a skilled manual operation with the operative having to adjust pressures and times of injection to achieve the optimum result. The waxes are carefully checked for defects such as, air bubbles, heavy join lines, flashing, sinkage, full formation of fine detail, and surface finish. The completed waxes are then passed to the building up department.
Building up the Tree
In the building up department we assess the waxes by size and mass to ascertain the best casting options. The general format tree will have lighter weight items towards the top of the tree, and heavier weight items will be positioned towards the lower part of the tree. Larger items may need special consideration in the manner they are built up and positioned in the tree. With heavy items the standard waxing feed may be dispensed with, and a still larger feed applied as required. Also with some larger, and heavier items they may be separated into a special tree requiring revised burnout and casting parameters.
When it comes to building up for platinum there are additional considerations to prevent the shrinkage hole effect often seen in heavier platinum casting just at the point of feed. We have developed many differing tree styles to accommodate special requirements.
