hi john b., john h., skip, jess, ken, vernon and everyone who
helped me with my problen of bubbles on the castings,
here is an update: i corrrected all the equipment problems.
cleaned all the hoses, changed the oil and flushed the vac unit
(but still only get 27’’), got a larger vac table etc. i’m glad
i did all that stuff because it needed doing but i know it
wasn’t the cause of the problem. the real problem was using too
cold of water and a mixture that was definitely too thick.
you all will be happy to know (i’m the happiest tho) that i had
one bubble only on my entire legion of flasks cast.
a few water marks on large pieces at 42/100 mix, so i will go to
a 40/100 and see what happens. i started out with 80F water and
what the investment temp when finished investing was only 60F,
tho it felt warm to the touch. strange, eh? i will check this
again next time.
thanks again and again.