Hi all. I thank all of you who helped me solve my porosity
problems. Today I cast 5 flasks (about 10 pieces) and tried some
of the suggestions submitted by y’all. I cast 4 of the 5 flasks
with vacuum and didnt have any porosity. The 1 flask I cast in
the centrifuge, had porosity on it. I guess I will switch back to
vacuum casting most of the time now. I am curious to try winding
the centrifugal caster 1 or 2 turns instead of 3 turns to see if
that helps any.
I used the sprues with the resuvuoir on them and I think that
helped. I also cast at a slightly higher temp (1050F). Anyway I
think I am back on the right track again.
Thanks to all. Ken