On Sat, 8 Nov 2003 09:52:17 -0500, "George"
wrote:

I'm not sharp, but I can look things up.

30 micron is about 320 grit product.
http://www.taunton.com/finewoodworking/pages/w00006.asp Otherwise 99.44% of
what you produce is larger, and you still have distance from bag, gravity,
and your body defenses besides.

For fine dust, I've found that a good powered air filter and/or dust
mask helps more than small micron bags. Standard small micron bags
seem to cut the flow down quite a bit on non-industrial sized
collectors. The cartridge filters now available have a lot more filter
area, so the flow rate should be kept up and smaller particles can get
grabbed.

One of these days, I'm going to add a cartridge filter to my 2 HP Jet.
I was not happy with a 1 micron top bag.

This is simply my own limited experience.

Barry