Dear Daniel Grandi: I liked you comments and printed them out so
I could read them again and try your suggestions. I live in Estes
Park and teach my classes in Boulder and Loveland. It is hard to
get the inches of mercury your talking about, but I will work on
vacuum casting some more. I do make about one or two vacuum casts
a month just to demostrate it. I still do not see much importance
about the vacuum pressure that in achieved. I do not believe that
it is the vacuum that pushes the metal into the mold, it is the
amount of air that rushes through the flask, pushing the metal
with it. Am I wrong here? I really am wanting to learn, not
being smart. I really believe that if you hand a bell jar the
size of a 55 gal drum and created a vacuum in it, you would have
a better vacuum caster. More suction! I still think “suction” is
air pressure tring to equalize the situation and not really
"suction". I really do apprieciate this discussion. You also
really hit home with the fact that people can and will find a way
to get hurt doing any kind of casting. In fact I burnt my
fingers by grabing a very hot t-pin last month. It was a pretty
good burn. It was the first time I have ever burnt myself (or
anyone else, of course) in 25 years + doing silversmithing. I
still can not figure out how anyone can get hurt doing centifigal
casting. If junior high kids could not do it in 13 years, it
seems impossible! hehe! Thanks again.
Don Norris
@Donald_Norris
PO Box 2433 Estes Park, CO 80517