> Some other thought:

The use of a shop vac to your sander is a good idea. In addition you can buy paper filters that go over the standard foam filters to trap small particals. I think they are made for dry wall sanding. This is important also for sanding epoxy as that can also be nasty stuff. Lastly if it isn't feasiable to locate your shop vac outside you can put two chairs next to it and drape a plastic sheet over the whole works. This keeps any dust not captured in the filter from blowing around the shop. I did this in my basement for the whole project (in addition to using a resperator) and had good results.

An added benefit is you can start epoxying or varnishing right after sanding without worrying about airborn partical floating down on the surface

I agree with Don, using a vacuum attached to a random orbital sander can
> make sanding in the garage possible. I used to do it all outside,now the
> vacuum goes outside. reducing the exposure at the source is a good way to
> go as well as preventing inhalation.