Lost Wax Casting
When Investment Casting, a negative mold is made. This means that the shape of the product is milled into a block of aluminium as a hollow space. This space is then filled with a highly pure wax. We then add pouring holes to a group of these wax models and attach them to a sort of wax “tree”. Once multiple models have been attached to the tree, the tree with the models is dipped into liquid porcelain to create a porcelain layer around the wax. When the result is put into a steaming oven, the wax melts and leaves the porcelain shape, which can then be used to pour metal into.
This method uses expensive materials, and is one of the costliest ways of pouring metal. Investment Casting is primarily used for low weight complex parts, when the quality of the surface is important and the permissible tolerance low.
Yellow Wax Casting
Again, a model is milled into a block of aluminium to make a wax shape, which is then used to create a porcelain mold. The difference is that Yellow Wax Casting uses lower quality molds and wax, resulting in higher tolerances but lower costs. It is more labor intensive, which is why this method is mostly applied in low-wage countries