WAX MODELLING

As the name suggest the process of wax modeling beings with creations of an original model.

Original models for casting can be made of either metal of wax. Metal models are usually made by commercial jewelers who need to make duplicate castings from was models produced from rubber models. Wax models are usually used by jewelers who either produce one of a kind jewelry pieces or as the original model for a metal model.

The advantage of using wax to create a model is that wax is relatively pliable and soft and thus can be easily worked. Wax model making therefore offers a wide range of design possibilities. We can obtain textures and shapes in a wax model that could never be achieved if the design were made in metal.

Commercial waxes are available in various colours, hardness and shapes. The colour is usually indicative of the different working characteristics of each was and hardness. Tube waxes can be used to quickly create a basic ring shape. 

WORKING WITH WAX: Design can be achieved by using different manufacturing techniques such as cutting, carving, engraving, sawing or drilling. Various texture can be applied to the surface of wax model by means of a hot needle, spatula, knife edge or carving tools. A rough texture can be applied by rubbing the wax model with a fine wire brush.

Some model makers use an electrically heated spatula (with interchangeable tips) which eliminate the manual heating of a spatual over a flame. The one in image also has a temperature control.

Weight and size should always be considered when making a wax model. The finished metal casting weighs approximately 10 times more than the wax model if it is cast in sterling silver and approximately 15 times more than the wax model if it is cast in 18 karat gold.
Determining the Weight

Multiply the weight of the wax by the specific gravity of the metal

Wax     x     Specific Gravity     = Weight of metal

Aluminium	2.7
Brass (70/30)	8.5
Brass (88/12) Nu-Gold	8.7
18K Yellow Gold	15.5
14K Yellow Gold	13.4
10K Yellow Gold	11.6
Iron	7.9
Lead	11.4
Nickel Silver	8.8
Platinum	21.4
Fine Silver	10.6
Sterling	10.4