Have I just been really lucky and done that with no problem, or is
there a specific reason that carving or milling wax should not be
it’s not that you can’t, it’s just that it doesn’t work so well.
Most carving waxes have a melting point too high for steam dewaxing
to melt out the carving wax. It does remove your sprues, so at least
there is that.
But try it. Boil some water on the stove with a chunk of your
carving wax floating in it. (most steam dewaxing equipment doesn’t
get the steam much hotter than boiling water) Does it melt fully? If
so, you can steam dewax. If not, you’re wasting your time. It doesn’t
hurt anything to try, but if it isn’t removing your wax, then there
is little benefit to bothering to do it.
Do note that you might have another option if you wish to steam
dewax higher melting waxes. If you were to try this with a pressure
cooker rather than the usual dewaxers that operate at normal room
pressures, you’d get higher temperature steam. That might be able to
melt the carving wax. You still might have issues with the viscosity
of the wax even if molten. Some carving waxes simply never get runny
enough when melted to really flow all that well. But hey, try it and
see if you like.
If you can get it to actually work, there are some benefits to steam
dewaxing. For one, fewer burnout fumes, and you can use a shorter
burnout and still have fully removed all carbon residues in the
investment. For another, carving waxes in particular sometimes have
higher rates of thermal expansion before they melt. In some cases,
this can cause more stress on the investment, causing cracks or
breakage of details, especially with fast burnouts, or improperly
mixed investment. Steam dewaxing might be more gentle, That’s just a