Den wrote:
I want to try putting together a quick vacuum generator that runs off
compressed air (run of an 8 gallon tank up to 130 PSI.

I'll be using it for desoldering so I think I want a reasonably strong
vacuum, but the volume is not all that high. It will probably be used in
"burst mode" - with a burst of vacuum for a few seconds being needed
intermittently.
A commercial unit is the "Ped-a-Vac", I think it has a 2-stage
venturi system, and gets a strong vacuum even with some leakage
at the tip. You might look on eBay for one.

Jon