Collecting Dust or at least preventing the distribution of dust in the workshop has been an active topic among woodworkers for a long, long time and I expect it will continue to be as new information, changes in the industry and new methods continue to evolve.
The one thing that hasn't changed is that we all pretty confident that wood dust is not good for us to inhale. We seem to be at odds about how much is safe and which dusts are worse than others, but the safe rule of thumb is NO dust is good and ALL dust should not be inhaled. I think every woodworking shop I have been in has some amount of dust in the air, what we all do is strive to reduce this dust as best we can. One way of reducing dust is with dust collectors.
For smaller shops like mine, a typical dust collector is often a 1.5 and up to a 3 horsepower electric fan that draws dust from our machinery and deposits the dust it into a plastic bag while using an upper cloth bag or composite canister to filter the small particles of dust and return fresh air to the room. These are often not the best, but for many of us they are best we can afford and install, and in recent years they are actually doing a pretty good job. These units with collect and expel dust in one unit are called Single Stage Dust Collectors ...
One of the problems with single stage dust collectors is that they are often hard to empty when they get full, without causing more dust. For this dust masks are highly recommended.
One of the first upgrades to a single stage dust collector is to make it a "Two Stage" dust collector by adding something called a cyclone style extractor to the existing unit. This effectively takes the single stage dust collector to a 2 stage collector.
The purpose of a dual or 2 stage dust collector is try to make the air cleaner by trapping more dust in the first stage of the dust collector which turns out to be the cyclone part that was added on. The way this works is that most of the dust is collected in the first stage, the cyclone stage, thus preventing much of the dust to enter the second stage, which in turn helps to cut down on dust particles being expelled through the dust collector's filtering system.
Another advantage of the 2 stage collector system is that often it is easier to change or replace that part that is collecting the dust. Often these are barrels or large canisters that easily detached thus, also helping to reduce the dust collection in the room.
In my case I have added and Oneida cyclone style collector to my existing dust collector. I only ordered the cyclone part, not the dust collection part because I wanted to set up my own collectors so that I could add more as needed. Over the years I have amassed a small collection (3 or 4) of identical, plastic garbage cans, of good quality. They are all identical, except for color and the rims have nice flat parts which make them very suitable to adapting to a cyclone collector top.
All I had to so was to make a base for the cyclone collector to sit on, which I did with a couple of layers of plywood, the bolt the cyclone top to, making sure it was well sealed.
When ever you are working with dust collectors it is imperative that they be as air tight as possible, otherwise their efficiency drops drastically. I had to make sure the cyclone was sealed to the wood, and that the wooden top could seal tightly to the plastic garbage can bases.
Next comes the piping. I used flexible plastic tubing designed for dust collectors. If you use piping designed for home clothes dryers for example, the suction of the much higher pressured dust collectors will collapse the tubes, so you need plastic tubing designed to carry the load. The piping needs to be connected tightly between the units and there are special hose clamps for this that give a better grip to help reduce air leaks. If you have any size changers on your collector that you need to reduce or expand the sizes, it's recommended that you use aluminum ducting tape (not fabric duct tape), to also help reduce any chance of air leaks.
And after all this is done, you finally get a chance to test the system by cleaning out the 2 stage of your collector and seeing what it can do. I was very happy with mine. I found that very few dust particles were making it to the second stage, which means the air in my collector was probably coming at least somewhat cleaner than before.
There are a few changes I still want to make on my system. I am thinking about putting the whole thing on wheels so it can be moved around if needed. My shop always seems to be in a state of re-arrangement so having all my tools on wheels is important. The other thing I still want to change is how the lid attaches to the collection barrel underneath. I have not seen a system so far that I like, that can be quickly and easily changed and will adapt to 3 or 4 other barrels for quick swapping. For now the small bar clamps work but there must be something out there that is a bit more elegant.
After having run this system for a few weeks now, I am happy to report the dust collector barrel indicator, the little bar that I push down to see how full the barrel is, works great. I have had 2 barrels full so far and no overflows ... at least so far.
All in all I am very happy with the system. I can't really tell that has reduced the dust in my workshop but it has made collecting the dust easier, more convenient and far less dusty than trying to unhook plastic bags full of dust and get them out of the workshop. I still wear a dust mask and probably always will, you can never be too cautious about inhaling dust ... the less we inhale the better.
Copyright Colin Knecht