Here we are; goggle eyed from all the studio work!

We are going to use the ‘Lost Wax Casting’ technique to turn the wax fish into bronze. The oldest known examples of this technique are the objects discovered in the Cave of the Treasure (Nahal Mishmar) hoard in southern Israel, and which belong to the Chalcolithic period (4500–3500 BCE).

Simply, the wax fish need to be covered in a clay mix. That clay is then dried and put upside down over heat to pour out the wax. This leaves the negative space of the fish. The clay mould is then fired in a kiln to make it stronger. Then the bronze is melted in a furnace and poured into the mould.The mould is broken and reveals the bronze fish.  But of course it’s not that simple.

This is what we have been doing to prepare moulds of the sixth class fish.If we made our moulds as simply as described above   we would get air locks when the bronze is poured in so there are lots of time consuming jobs to do first. We will try and describe it to you with photos.

First we have to make the clay mix, which is clay, sand and horse dung. We speed this up using a pug machine.

wax fish

We have to add extra ‘sprues’ of wax to the fish to act as ‘breathers’. These are pipes of wax which will become air channels when the bronze is poured in to stop air locks.We also have to add pouring cups. This is a funnel at the top to pour in the bronze.

These wax sprues and cups are attached to the fish. We have to decide the best point to attach the pouring cup so that gravity will work when pouring the bronze.

The fish are now ready to build moulds around them.

They are dusted with ash – this helps the clay to adhere to the wax. Two layers of ‘slip’, which is a watered down clay are painted on to the surface of the wax.This ensures that the clay gets into every crevasse and texture in the wax. Then several layers of the clay/sand/dung mix are added.

These will now have to dry before we go on to the next stage of melting out the wax.