< COLOURING WAXES

A BRIEF GUIDE TO WAX BLENDING & COLOURING

The mixing and blending of waxes and non-wax additives is best carried out in jacketed melting vats, with the blend constituents isolated form any direct or naked flame heat source for safety reasons. Commercially manufactured blends are processed under highly controlled conditions. Art foundries that blend their own waxes ‘in house’ usually do so in far smaller quantities and under somewhat more variable conditions than the commercial manufacturer – though low volume processing does at least allow the founder to create special blends for ‘one off’ jobs with relative speed and economy.

The constituent ingredients of the blend, including colouring agents, are added into the base wax product after it has been melted in the vat. Care is taken not to overheat the contents as molten wax is highly flammable with a low flash point. Wax also evolves a fume that easily ignites in the locality of a naked flame. It is important that all the ingredients added into the blend become evenly dispersed, so a gentle stirring of the vat’s contents will usually assist distribution.

Some artists who work directly with wax, prefer to blend their own wax preparations to suit their personal preferences. For those artists who would like to experiment with wax blending, but who have not had any experience, the following points may be helpful:

When experimenting, make small quantities of each blend, but ensure sufficient amounts are available to be effectively tested in the studio.

Keep careful records, and clearly identify each experimental batch for future reference.

Add the blend’s ingredients gradually and in order – start with the largest constituent (by volume) and finish with the smallest.

Research in advance the likely compatibility of additives, and never add substances with more than a trace water content.

Handle molten wax with great care and treat as a highly flammable/low flash point material.

Wax fumes are hazardous, take appropriate precautions to protect yourself and others.

Molten wax can cause serious burns. Wear protective personal equipment, including gloves and an impact/heat resistant face shield. Preferably use multi-element, double jacketed vats which are specifically designed for wax melting. If using other containers, especially domestic pans heated over electrical elements or gas burners, take great care not to create an underlying reservoir of pressurised molten wax beneath set wax from previous meltings. The crust will eventually soften and rupture, causing trapped wax to explode with potentially injurious results.

Commercial wax suppliers and retailers will usually be able to offer advice on suitable products for a particular purpose. In many instances, manufacturers will be prepared to supply samples of their own pre-blended waxes for studio testing. Some foundries may also be willing to supply quantities of wax to clients who wish to make their own wax patterns in the studio, later returning the pattern to the foundry for casting. The supply of a foundry wax to a client is often seen as preferable to cross contamination with a foreign blend (usually this occurs during materials recycling).

CREATING A CAST WAX PATTERN >