I made a dustless and explosion proof vac system that is pretty easy. I don't have a pic of it right now, but I'll post one later. Start with a suction tube from a shop vac. This tube goes into a 5 gallon bucket, with a lid gasket so it's sealed relatively well. bucket is filled half way with water, and suction hose from shop vac is ABOVE THE WATER AS FAR AS IT CAN BE. a second hose is below water line, and exits the bucket. seal all openings (caulk, GOOP, etc). What ever you suck in, gets trapped by the water. If you're worried about vac motor in an explosive environment, you can park the shop vac in a different room, and have a long hose connecting to the bucket.
If you search for "DIY water filter vacuum" you should find lots of examples.