Click here for basic information about the
lost wax casting process.
In the lost wax casting
process, wax can be removed from the mold using several approaches,
ranging from heating the wax-filled investment in the kiln to steaming
to remove the wax. The key to both approaches is that the
investment must be dry prior to attempting to remove the wax.
To remove wax by heating in the
kiln, invert the mold over a pan of water and heat to about
225F/110C. The wax will drip out
of the mold and into the pan. Be careful not to heat much above this temperature.
You also want to maintain some water in the pan in the kiln, so you
may need to add additional water as it evaporates.
Since wax is flammable,
it can catch fire or even vaporize if it is allowed to get too hot.
For this reason you should avoid heating wax above its flash point.
The flash point is the temperature at which wax bursts into flame;
this can vary by type of wax, but a good rule of thumb is never to
heat wax above 300F/150C.
It probably won't be possible
to remove all of the wax by this method. This will require
that the remaining wax be burned out of the mold prior to filling
the cavity with glass and casting. This process will be
discussed in a future section of this tip.
Click here for information on steaming wax out of the mold.
Copyright 2006 Brad Walker.
All rights reserved.