Lost wax technique is a suitable way for casting bronze sculpture which has complex structure and delicate texture. One of the benefit of lost wax technique is it provides sculptor an opportunity to refine or improve the wax work before bronze casting.
The key factor of a successful bronze casting using this technique is to make excellent wax mould. The quality of wax mould affects the quality of bronze casting directly and there are two things to consider for making good wax mould.
(1) Ways of forming wax mould
(2) Using proper type of wax.
Generally speaking, there are three basic approach of making wax mould.
- Compressing: put wax block into a compressing mold make from metal, rubber or plaster and just compress it to generate the desired shape. This is a quick way to make multiple copies of wax mould. Wax mould made in this way is usually of high quality, showing clear outline and details.
- Irrigation. It’s hard to use compressing way to form some shape such as human bust. There where irrigation way stands. Pour molten wax into a negative mould (usually silicone ) and keep it cool for a while until the wax wall forms and then let go the molten wax. By this, we can get a wax mould without seam. This technique is relatively hard to operate because you must be very sensitive to wax temperature.
- Brushing. For those sculpture with simple shape, brushing is a good way. It’s simple to operate. Use a brush to dip into molten wax and brush onto a negative mould to form positive wax mould. Make sure brushing all over around and the thickness of wax mould consistent.
We will talk about the details about tips on making good wax moulds in the next few articles.
(Owen Weng)