I have been using my Neycraft Centrifuge for casting but as it is
hard for me to wInd, am considering using my Rio vacuum—the one
which uses the same table for investing and casting.
I know that I must not fill the flasks all the way to the top for
vacuum investing, but have a question about spruing. One of my books
on casting states that for vacuum casting, the sprues should be much
thicker than for centrifuge casting. Currently when I use the rubber
base with the doughnut center, I have been using 8 gauge for the
sprues. When I tree the models I have been using trees 3/8", for
several models, and 1/4" for about 2 models. Is my current spruing
method sufficient for vacuum casting?
Another related question. When I cast with the centrifuge, I always
tilt my models slightly. However, the author of one of the booksI
have on casting states that for vacuum casting the sprued models
should not be tilted, but should be horizontal --no tilt. Another
books states that the models should be prepared exactly the same as
for casting with the centrifuge, the only exception is the filling
of the flasks with the investment.
Thanks for all you help