I produce a lot of "scrap" virgin wax and being frugal re-melt it. A
double boiler set up won't work, can't get above 212 F with water
and you need more .
A stove with direct heat should work but what I use is either a wax
injector I built just for carving wax or an old pop can over an
alcohol flame. (Safety bees need not reply, I know the risks and
dangers, but a double boiler with 250 F oil is not that safe either)
Mold release usually not required. Pour at the lowest possible
temperature, as close as possible to the wax freezing in the pot.
Shrinkage will be reduced, pour too hot into an open mold and the
centre will really suck in or the block will crack in half, or both
With the injector and a plexiglas mold I keep the pressure on
until the wax solidifies. (patience or a combination of a rope and
Re-melted wax is different, at least the colour is darker. Other
properties might change slightly too, I haven't really noticed.
Probably best to 'age' it a day or two, I remember hearing that
melting changes would tend to heal with time (?? Kate Wolf ??) and it
is better that a too hot pour split before you carve it.
It IS possible with practice and persistence, I do it a lot but only
for in house work and tests. For larger blocks I would investigate
places like or for 'machinable wax'
Analog/Digital Modelling & Goldsmithing