I have an old vacuum caster unit. I bought it in the late 70’s, had
it stored for 25 years, put it into service in my studio, but never
had it serviced. I finally broke down recently and sent for a
re-build kit for our Welch vacuum caster pump. My tech guy did a
terrific job replacing all the gaskets, scraping off the years of
gunk inside, and generally put it back together as good as new. We
checked all the hoses, connections, etc., and the bell jar and pad
seem to make a tight seal. We thought we were pump gods until we
turned the machine on.
Unfortunately, the gauge now shows that there is absolutely NO
improvement in suction pressure! The gauge shows just over 26 (
pounds, inches, or what?) pressure, not quite enough to evacuate all
the bubbles in our investment mixes.
We’re out of ideas here, short of bending the needle to show more
pressure than the machine really has.
Anybody got any ideas for us to get more vacuum pressure, short of
buying a brand new unit?