I am getting ready to cast my wax models using my vacuum caster. In
reviewing Tim McCreight’s Practical Casting, Page 41, he emphasizes
the necessity of having the flasks bone dry before putting them into
the kiln. However other sources stress that it is necessary to have
some moisture in theflask and not to let them get absolutely dry.
In the past, I have always put my flask in a cold oven, when the
investment has glossed over and has solidified, but is not bone
dry—just very slightly damp.
However, I have been concerned that as the kiln heats up there is
some steam arising from the flasks during the initial time of the
burnout, and wonder if this is harming my kiln.
I keep the vent open until all the wax has dripped out, which does
keep any moisture from being trapped in the kiln. but am puzzled as
to whether the flasks should be bone dry, or slightly damp.
Thanks for your suggestions. Alma