Liz, you cant use the same collector on wood and metal at all - not even once.
The metal sparks will ignite the sawdust. Or the bags. Or the oil smoke will blind the bags. Metalworking needs a wet collector, or simply an outside vent.

: Does anyone have any experience with portable (or semi permanent) dust
: collection systems for a small house basement workshop? It would be used
: on one machine at a time. We're looking at a two dust bag system (2
: micron) with a 1 hp motor. We don't want to build in a major shop system
: but need to reduce the amount of dust we're producing on my boatbuilding
: and my spouse's metal working.