… before you kick it down to 8-10 psi for service?
If your beer is good and cold, crank it to 30, shake the crap out of it for a mintue or so. Leave it at 30 for 2 days total, then vent the keg and set it at your desired serving pressure. (8-10) You should have good carbonation in 5-7 days total, just test it on the fifth day. That’s my force carbing schedule anyways. It’s worked great for me.
depends on the style you’re brewing (hefeweizens are more highly carbonated than english bitters, for example) and also on temperature. the colder the beer is, the more easily/quickly it will accept carbonation. refer to one of the many online carbonation charts, such as http://www.kegkits.com/carbonation.htm for guidance on the amount of pressure to set your regulator at a chosen temperature to achieve a specific carbonation level. it’s not a quick process, but you can speed it up by shaking the keg, and accelerating the rate at which the CO2 enters the beer.
There’s many ways…
If I’m in a hurry I crank it up to 30 and sit there a rockabyebaby the thing for 10 minutes… voila…drinkable, though not perfect. Service pressure for a few more days and it’s good.
I force carb at 30psi for 48hrs then reduce to serving pressure and hold there. I don’t use the “shake method” unless I’m in real hurry which is very rare because I typically have several beers on tap at any given time. I also use the “set it and forget it” method if I’m not ready to serve the beer really soon.
It depends… there’s no true way to estimate. That’s why I always set at serving pressure… you can still shake to speed up carbonation.