The vacuum pump I made from PVC pipe and fittings worked okay. Pumping myself into a frenzy only got me slightly over 25″ of vacuum, which was acceptable for my uses. However, it was the “frenzy” part of using it that got to be expensive. My back is made from glass rods and broken promises and it does not respond well to anything that has “frenzy” attached to it.
While I was researching vacuum pumps, I ran across a vacuum pump that is intended to be used to evacuate automotive air conditioning systems. And then I found a YouTube video where someone had used that type of pump for purposes of degassing. Harbor Freight has it; their item number is 98076 at $100. It’s a 2.5 CFM (cubic feet/minute) pump with a 1/6 hp 110V motor. The only modification I needed to make was to unscrew the fitting for a/c systems and screw in a 1/4″ barb for the vacuum hose:
It’s a LOT easier on my back to flick a switch! It takes very little time to generate 29.5″ of vacuum and that makes a noticeable difference. If you’re going to be doing little degassing then the PVC manual pump would probably suffice. If you’re going to be doing more than a little degassing, I recommend getting something like this.