"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
Ed Huntress fired this volley in
:

You won't get them out of the system with a
vacuum on that order, if I understand the problem.


That's why a good pump with a fresh oil change will do 20 microns.
Mine
will, and I only paid $169 for it. I'm not happy with a system
until it
will hold 50 microns after I turn off the pump.

Lloyd

What do you use to measure 50 microns? My best 6" diameter mechanical
absolute pressure gauge stops at 100, and I don't have mercury for a
McLeod gauge.