Dust Collection question

[DLBrothers]

I need to put in some kind of collection system - I was looking at the smallest unit from Grizzly when it struck me that the ones made for sawdust may not be appropriate due to the particle size and nature of the metal dust from my KMG (really the only place I need it). I also just considered piping it outside, so particle size would be inconsequential, correct?

What is the concensus out there on the issue?

 

[SBuzek]

I think I have about the same unit but from Craftsman.Got it piped up under my grinder and then just took the bag off and set it outside the door and let it blow.The grass seems to like the added iron.
Stan