Any one out there using the Busch Mink Series vacuum pumps? I am interested in the vacuum levels achieved and whether there are any maintenance issues. I would think these pumps would be more prone to damage if they were hit with a surge of sap than a liquid vane pump. Also I have concern about traces of sugar gumming up the lobes in the pump since they run with very close tolerances.
On the plus side the price seem reasonable, one eliminates the need for oil or water and they seem to achieve relatively good CFM's at low pressures.