Dust Collection: Our Favorite Subject
In 2002, wood dust went from being a nuisance to an official health risk. That’s when the U.S. government put it on their list of “known carcinogens,” linking it to a variety of nose, throat, and lung cancers. But it has taken our corner of the woodworking industry a while to catch up with reality—in the form of the dust collector.
Collecting and exhausting dust at its source, before it reaches you, is the most efficient way to deal with wood dust. That’s why woodworking machines—from tablesaws to disk sanders—come with exhaust hoods or ports. “A typical exhaust hood,” industrial hygienist Richard Supples of Applied Improvement Technologies in Shelton, Conn., explains, “creates a capture velocity and effectively ‘grabs’ the dust particle and transports it through a duct/filter away from the worker.”
The trouble with older woodworking machines was that their exhaust hoods and ports were, at best, ineffective—and often nonexistent. But improvements have been steady and significant. If you are buying new machines or power tools, look for products that make dust collection convenient and effective. For your existing tools, take a day in the shop to improve the ports.
Fifteen or twenty years ago, if you collected dust at all, you probably did it with a single-stage collector and a 30-micron polyester bag. Those porous bags act like fine-dust delivery systems, blasting out a cloud of the most dangerous stuff at head height. Ironically, the people who didn’t bother with dust collection at all, leaving big piles of sawdust under their tablesaws, were probably safer!
Not surprisingly, the most dangerous dust particles, the very fine ones, are also the most difficult to collect. Particulate smaller than 10 microns hangs in the air the longest, penetrates deepest into the lungs, and is the hardest for the body to filter and eject.
Tool companies eventually decided to get serious about filtration. Enter the pleated filter, which can pack hundreds of square feet of surface area into a small canister. That lets you get much finer filtration without killing airflow/suction. If you are in the market for a dust collector or shop vacuum of any kind, look for the ones that use a pleated filter. But let’s first talk about the power plant, the dust collector itself.
Why the cyclone dust collector is king
A cyclone has two stages. Dust is drawn first into the cyclone itself. All but the very finest particles fly to the outside of the cone and spiral down into a collecting bucket, leaving mostly clean air to be drawn up through the center of the funnel cloud and into the filter stage.
There are two main types of dust collectors: single-stage and two-stage. Two-stage collectors draw air first into a separator, where the chips and larger dust particles settle into a bag or drum before they reach stage two, the filter. That keeps the filter much cleaner and free flowing, improving suction. That means a two-stage system can accommodate a much finer filter than a single-stager, which is better for your lungs.
The most effective kind of two-stage system is the “cyclone,” which uses a funnel-shaped drum as the separator, or first stage. Dust spins around the outside, which gives bigger particles more of a chance to settle out before the smaller stuff escapes to the filter stage. If you can afford one, buy a cyclone dust collector. The first cyclones for small shops were big, expensive, stationary machines, requiring long hose or rigid-duct runs to reach all four corners of a shop; now, almost every cyclone manufacturer makes portable, roll-around models, and they’re as affordable as ever. Many are under $1,000.
Improving a single-stage dust collector
More horsepower lets you park your collector. A 2-hp machine is strong enough to support about 18 ft. of flexible hose, which also allows for semi-permanent connection to several machines at once.
If you can’t afford a cyclone dust collector, buy the most powerful single-stage collector you can afford, with a bag or cartridge filter that will trap particles as small as 2 microns. Connect it to every machine in your shop. If it is big and powerful, you can connect it to multiple machines permanently, using a series of hoses and junctions, with blast gates to direct the airflow where you need it. With a smaller collector, you can roll it around and connect it to the machine you’re using. Long hoses sap suction, so keep the hose short with smaller dust collectors.
But be aware that the industry standard for filtration is 0.3 microns. If you want to get there, and truly clear the air, you will need a finer aftermarket filter for your dust collector. There are aftermarket models available from a number of manufacturers that will grab particles as small as 0.3 microns.
Keep in mind that these finer aftermarket filters clog quickly on single-stage collectors. If you don’t want to have to blow them out with compressed air each time you turn off the collector, you can add a separator stage, which turns your dust collector into a two-stage system. These are available in a couple of different types, from lids that go onto a trashcan to mini cyclones.
Add a dust mask or respirator to your arsenal
Despite your best efforts, you will not be able to collect dust from every source. Miter saws are notoriously hard to collect from, and how do you suck up all the dust from hand sanding? In these cases, a snug-fitting dust mask or a respirator is your next best line of defense. Look for dust masks and respirators rated N-95 or higher. If you have a beard, a dust mask or normal respirator won’t make an effective seal against your face. In that case, consider buying a powered respirator. These keep a positive flow of air going past the face.
Repost from: Finewoodworking.com
Keywords: Drill Press Collection System, Drill Press