I am currently working on trying to find a 30 gallon drum locally, not the barrel shape, but a true drum so that I can build a Thien Cyclone Baffle
http://www.cgallery.com/jpthien/cy.htm and hook it inline with my 12 gallon Ridgid 6.5 PEAK HP wet / dry vac. And yeah I know PEAK HP blah blah... It still does a good job, just plugs up really fast...
After seeing how fast a 12 gallon shop vac fills up, I would NOT suggest using a 5 gallon bucket based separator, but rather a 20 - 30 gallon vessel of some type. That shop vac will produce enough vacum to collapse a 30 gallon steel trash can once the inlet is blocked. Hence the reason I am looking for a drum...
Depending on your workshop setup, as long as you only run one tool at a time, and seal the joints with electrical tape to make them fit better and provide a good vacum seal, the Shop Vac Sawdust Collection System is a GREAT way to use your shop vac as a central dust collection system. Is it as effective as a true DC? There is a LOT of debate over that, not only here on the WW forums, but also with the auto refinishing crowd, and aviation tinkerers. I have access to a good number of engineers where I live since most of my neighbors are with NASA, the oil industry, or various smaller manufacturers. I am confident with my hobby workshop being a safe environment with my setup, and the cyclone can only improve it.
If you want to go full out with a dust collection system based on your shop vac, I would go with...
#1. Thein Cyclone. You will need to shop build this. A lot of guys are using 1/2" ply, or MDF for it. Either are reported to work well. I think Phil builds his out of 3/4" MDF and rabbets a lip into the top part. Unless you want to spend all your time emptying the cyclone canister, use at least a 20 gallon drum. 30 gallon is better IMHO. 55 gallon is a lot easier to get, but might be too big.
#2. I am assuming you are using a Ridgid, or Craftsman wet / dry vac. Only because I know where to find the link for the item I want to talk about here...
http://www.homedepot.com/webapp/wcs...7+787&storeId=10051&catalogId=10053&langId=-1 You will want to add a Gore CleanStream HEPA filter to keep any ultra fines from blowing through the filter and back into the air.
#3. Shop Vac Sawdust Collection System, or Ridgid Clean Shop Dust Collection Network. (The only difference I can see between the two kits, is the Shop Vac setup uses longer pipe segments, and the color of the blast gates). The Shop Vac kit from their website was far less expensive, and used longer pipe segments. I bought two of their kits, with shipping was less than $90.00
#4. Tool reducers for things like miter saw, sanders, etc... I found my particular miter saw needed to simply have a couple of winds of electrical tape to make up the size difference to connect to a hose.
#5. MANY bench top, and a good number of free standing machines have dust ports specifically made for the 2.5" shop vac fitting. If your ancient band saw, or el cheapo jointer don't have a dust collector flange, you will need to add one to each machine you want to connect.
#6. Bulk 2.5" hose, and screw in adapter ends. Peachtree woodworking is where I got mine. The hose comes in 10, 20, and 50 foot lengths. Even with the screw on ends, you will also want GOOD hose clamps, to keep the hose from spreading and walking off the connector.
#7. Drywall anchors to mount your tubing. The kits come with some, not enough. I prefer to use those expanding moly bolts anyway....
Mind you, even a dedicated dust collector isn't going to provide a 100% dust free environment, so you will need to add some sort of air cleaner. You can fab something up using a blower motor of some sort in a shop built box, and suck dirty air through a HEPA type filter, or simply add a 20x20 HEPA or Filtrete type filter to the intake side of a standard 20" box fan with duct tape. (My cheapo solution). Either way works.
There are certain tools that no matter your dust collection system, there is no real good way to collect the dust from the machine operation, these machines in particular are spindle / edge sanders, band saws, miter saws, and radial arm saws. I have probably forgotten some. Keeping an open garage door or window with a breeze coming through, and / or wearing a proper dust mask is certainly well advised.
Good subject, keep on making that sawdust, and keep safe!