With a little tinkering, a disposable Propane tank for a Coleman stove or lantern makes an excellent vacuum reservoir. It's much thicker than the "tomato can" reservoir and it can be fitted with a drain petcock to remove any oil it might trap. PM me for a sketch of how to do the modification necessary to convert one.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!