If you have known good oil (fresh), have your system chamber under a held vacuum, and almost never up to air, and only "let up your foreline" after turning the pump off, then only a minute or two of ballasting is ever needed.
You are just pulling down the foreline and freshening up your vacuum before operation. This does require a couple of well placed valves. Rank amateurs and beginners rarely have good valving on hand due to expense, but it saves so much trouble and time.
I find the people who need to ballast the most, either don't know what it is or don't do it, if they do. Careful and skilled vacuumists often ballast more than they really need to, but it is a good habit to get into.
Richard Hull
Created on Monday, April 30, 2001 2:58 PM EDT by Richard Hull