Hi All,
I'm interested in building a vac bag system. I have been to Joe Woodworker's site and have learned a lot. My problem is understanding the relationship between different methods of describing the specs on pumps. JoeWW says that a pump should hold at least 25" hg and VacUPress systems also describe their pumps in terms of inches of mercury. However, when I look at offerings on eBay or on the internet, they often talk about microns of vacuum. How do I compare microns of vacuum to inches of mercury? Also, I assume that the CFM rating just indicates how fast the pump will get down to its maximum vacuum capacity. Is the size of the electric motor that drives it (I'm not interested in a compressor driven system) or the mechanism of the pump (piston, rotary vane, etc.) of major significance to a woodworker?
Thanks for your help,
Mark Blumer (East Lansing, MI)