Whilst browsing ebay for vac pump, i got the impression that diaphragm pumps are likely to have low Cu ft/minute draw; ie they take too long to evacuate the bag unless it is very small, and the item being glued flat. If you want to laminate over a form (which may be hollow and thus contain air) most reccomend 3 to 4 Cu ft /min flow as minimum. Small diaphagm pumps may not work any better than a chest freezer comprssor on "suck" (1 t 1.5 u ft/min). The Dakota doeas not specify Cuft/min (so probably not very spectacular) and the bag is small.....