After the mold is finished the wax then needs to be
melted out of the mold leaving the inside of the mold empty and mostly
free of wax. The mold is placed upright with the pouring spouts facing
down. A small channel is made in the ground that leads to a small
pool. The channel and pool are coated with a mixture of sand and clay.
The clay that was placed on the ground to form a channel was placed
there so that the wax would not mix with the dirt. Thus the river of
wax can be extracted from the clay and used again for future wax molds.
10% of the wax cannot be recovered because it is burned away.
heat of the fire is not hot enough to melt all the wax form within the
mold. The excess wax is removed in the next stage of casting the mold.
The approximate amount of time the fire is kept lit from
start to finish is:
1 hour for a 12 inch wax mold
2 hours for a 24 inch wax mold
2 hours for a 36 inch wax mold
4 hours for a 48 inch wax mold
6 hours for a 60 inch wax mold
8 hours for a 72 inch wax mold