re: Danger of sawdust combustion?

There have been some pretty fascinating discussions about this over at LJ. I’m in the camp that there is pretty much zero risk until you step up toward industrial sized collection. The main idea being that there has to be a certain volume of both air and fuel to reach a sort of critical mass that you just can’t get from small dc units. Certainly not from the shop vac setup in using, but even from anything with 6" ducting.

There are plenty of other risks associated with DC but combustion caused by static discharge isn’t one of them. And always always always ground all of your equipment and outlets properly.