G’day; For a very inexpensive vacuum pump you could get what we
used to call a filter pump, and every laboratory has them. They
can be obtained from any lab supply house for a few bucks - only
problem is that you must have a mains water supply with a
pressure of at least 20lb/sq in. I used to make them in glass
(50 years ago!) and discard them if they didn’t ‘pull’ vacuum
of better than 3cms of mercury. They’re real suckers! Cheers.
/\ / / John Burgess, / / / //\ @John_Burgess2 / / \ \