Wednesday, August 27, 2014

My first bronze sculpture !

Once my fingers were well rested, I thought of adding the final touches to some of my earlier works. I added a new pair having a chat. Modified one of the earlier works into a seated woman and created a new piece for Amie and her parent’s birthdays coming up in August and September. Spoke to Mr. Ravi and decided to go ahead with coring and casting. The following wax models went for coring 2nd week of August.

Materials required:

Bricks for making the enclosure, clay for runners,
 sand, fireclay, plaster of paris and water for the mould. Wires to bind the mould.

1. Lay the bricks on the ground into rectangular shapes according to the sizes of the wax models.
2. Fix the runners made of wax or clay to the wax models
3. Place the wax models within the brick rectangles resting on the runners.
4. Prepare the aqueous mixture of sand-3 parts + fire clay- 1 part+ plaster of paris- 4 parts
5. Seal the joints between bricks with the mixture.

6. Pour the mixture so that it covers the model completely
7. Allow it to set.
8. Scoop out the clay to leave holes acting as runners.
9. Wrap the mould with wire and put another layer of thicker mixture to cover the wire.
10. Allow it to dry completely. This could take a couple of days.

Once the mould has dried completely, it is ready for de-waxing. A kiln is built with four openings for firing and the moulds with the runners facing down wards are placed inside the kiln on a rack. A small opening is kept at the top for the flow of air. The fire is kept burning for 3 to 4 hr and then the opening at the top is sealed. It is kept overnight this way to ensure complete de-waxing.

Scrap metal is heated with burning coke. When the metal melts, the plaster moulds are removed carefully from the kiln and placed on the ground with the runners facing up. The molten metal is then poured carefully with a ladle through one runner and allowed to come up through the other. 

Once the plaster moulds are absolutely cold, they are broken with a hard object to take out the metal sculpture.

After removing the runners and other supports the piece is polished by a process called buffing

After buffing the piece looks like this


The last step is to mount the sculpture on a pedestal. My first few pieces......

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