Janet Alexander from Flower Mound, Texas, makes a bronze figure that can be placed in a garden or as a decorative cover over a fireplace gas valve, using the ancient technique of lost wax casting.
Materials and Tools:
carving tools (files, knife, jeweler's saw, Dremel tool, etc.)
4" steel cylinder (a flask)
de-bubbleizer (wetting agent)
rubber mixing bowl
graduated measure flask
heavy leather gloves
carbon stir stick
metal weight scale
crucible for melting metal
bronze to cast with
eye protection (dark glasses)
casting flux (borax)
oxygen & acetylene torch
striker or electric lighter
bucket of water
* a plaster-like substance that is poured into the flask around the wax model
1. Carve a wax model. Place the model onto a wax wire (sprue).
2. Weigh wax to find out how much metal is needed.
3. Attach wax model and sprue to rubber base. Spray with de-bubbleizer. Attach steel flask to rubber base.
4. Weigh out investment. Measure water. Mix investment and water using mixer and spatula in rubber bowl (the investment will start setting up in 9 minutes).
5. Vacuum investment mixture for 2 minutes. Pour investment into flask. Vacuum flask for 2 minutes. Allow to set for 2 hours.
6. Remove rubber base. Put into oven to burn out wax for about 5 hours.
7. Balance casting machine. Weigh out metal on scale. Melt metal in crucible using torch.
8. Put hot (900 F degree) flask from oven onto casting machine using tongs and gloves. Cast metal into flask. Allow to cool about 5 minutes.
9. Immerse into a bucket of water, blowing apart investment, releasing metal item. Pick up metal item and clean investment off with a brass brush.
10. Use hack saw to cut off of extra metal. Grind down and smooth.