Woodworkers often think of adding a dust collector only after purchasing their shop’s essential machinery. But we encourage you to consider new or upgraded dust collection now, regardless of your current tool lineup. Hooking up your dust- and chip-making machines to a collector reduces your time spent cleaning, as well as—hopefully—the amount of fine dust that lingers in the air before eventually settling.
A fully ducted system with a large collector might be a luxury outside your budget. Fortunately, smaller, portable single-stage collectors can do the job well, and go easy on the wallet, too. These machines connect directly to a tablesaw, bandsaw, thickness planer, or other machine, typically with flex-hose. (See Stage Coach: Know the D.C. Difference, below.)
Stage Coach: Know the D.C. Difference
Single-stage dust collector
These collectors draw debris directly into the impeller (fan), which blows it into the adjacent filter/collection cylinder. The heavier chips and dust settle into the collection bag, while the finer dust rises to the filter media (bag or canister) above, where it either gets trapped or, worst case, passes through the filter and returns to the shop air.
We tested eight single-stage dust collectors priced from $325 to $850, including one unit with both bag and canister filter options. Here’s what we found.
Two-stage cyclone dust collector
Whether portable or stationary, these machines suck dust into a separation chamber that tapers into a cone. The heavier chips and dust settle into the collection bin below, while the finer dust gets sucked into the impeller above, and then blown into the filter. The primary benefit with a cyclone is that most debris never reaches the fan or filter.
Airflow starts the process...
The volume of airflow generated by a dust collector is expressed in cubic feet per minute (cfm), the industry specification for measuring a collector’s ability to gather debris.
Meanwhile, resistance against airflow is measured in inches of static-pressure loss (sp). As you add more resistance (ribbed flex-hose, elbows, reducers, etc.), you reduce the airflow through the duct, and thus, the collector’s ability to efficiently move debris.
Using a pitot tube, manometer, and smooth-wall metal duct, we measured each collector’s maximum cfm performance at various levels of static-pressure loss. Using that information, we generated fan curves for each unit. Download our fan curve chart at woodmagazine.com/dcfancurves.
Although a fan curve provides important data, it’s hard to translate that information into performance in the shop. So, we also used a 10' length of 4" flex-hose to hook each collector to a tablesaw, bandsaw, planer, and drum sander to gauge their effectiveness in actual-use scenarios. Six of the eight models have 6" inlets—the Rikon 60-150 and Supermax 821200 have 5" inlets—but all come with a 4" wye, letting you more easily connect to the 4" ports common to most woodworking machines.
As you can see in the airflow chart above, collectors perform disparately in the same woodworking scenario (collecting dust from a drum sander, in this case). The Powermatic PM1300TX-CK and Jet DC-1100VX-CK maintained most of their cfm as dust built up in their canister filters. Conversely, the Supermax 821200, Shop Fox W1685, and General International 10-105ACF M1 dropped off substantially with dust buildup. With these three machines, it’s important to knock dust from the filter media more frequently to maintain adequate airflow.
Generally, it takes at least 400 cfm to keep dust and chips suspended in ductwork. We found lesser numbers workable, but only in 10' or less of duct. Follow these best practices to maximize airflow:
■ Flex-hose quickly robs a collector of cfm, so use segments as short as possible. Actual cfm numbers with even a short piece of flex-hose measured about one-half to one-third of the ratings specified by manufacturers.
■ If using two runs of flex-hose on the wye, install a blast gate on each line so you can shut down the one not in use to maximize airflow through the hose being used.
■ Planer chips will more likely hang up in flex-hose than will dust with one of these collectors. If you notice this happening, shorten your hose or eliminate bends in it.
■ As dust builds up and seasons the filter, cfm will drop. Even if you knock dust from the filter, it will never return to its out-of-the-box airflow performance.
...and filtration completes it
Getting the debris to the collector is only half the battle. The other half—filtering out the fine dust and returning clean air to the shop—proves more challenging. Thankfully, nearly all dust collectors today come with a filter rated to trap most dust particles 5 microns or larger. Better still, six of the eight test models claim to trap nearly all particles as small as 1–2.5 microns. The most damaging particles are those smaller than 10 microns, because they stay suspended in the air longer, where you can inhale them. These tiny particles are also the most difficult for your lungs to expel. (See the chart for each machine’s filter-efficiency rating.)
To equally evaluate each collector’s filtering ability, we used a Dylos particulate meter to measure air quality before, during, and after each test. This sensitive meter detects particles as small as 0.5 micron.
As you can see in the chart above, some machines fared better than others, with bag filters generally outperforming canisters. The Jet DC-1100VX-5M, using a 5-micron bag filter, excelled by keeping the most fine dust trapped. The General International led all canister-filter models, finishing second only to the Jet DC-1100VX-5M. To be fair, all eight machines’ performance exceeds industrial regulatory standards established by the National Institute for Occupational Safety and Health (NIOSH).
The buildup of a dust cake, shown below, helps all filters trap more dust, but at the expense of airflow. So, over time, you’ll have to get a feel for how your collector performs: As collection seems to drop off, clear some of the dust from the filter to improve airflow. We found that cleaning a canister filter reduced its filtering ability until a dust cake built up again, but not as noticeably with bag filters. And lower airflow means more dust at the source will likely get into the shop’s air.
We also discovered that each machine had small leaks where dust escaped, sometimes particles so tiny we couldn’t see them, but could feel the air movement. Before beginning our “official” testing, we sealed up leaks around metal seams and welds with silicone sealant or duct tape, and used adhesive-backed foam weather stripping to improve the seal around bag rims.
More factors to consider
■ Removing/installing bags. All eight machines use plastic collection bags. Although they’re meant to be disposable, they’re thick enough that you should be able to dump the debris and reuse them several times. Before removing a collection bag, knock dust loose from the filter bag (or turn the beater on a canister) to prevent big globs of dust falling out while you’re working on the lower bag.
Filter or collection-bag clamps must hold securely in place while maintaining a tight seal against dust leaks. But these should also be user-friendly, and some simply are not. (See the chart.) The Jet and Powermatic machines use setscrews to hold their canisters tight to the rim, and interior hoops to hold the collection bags (above). Other models use band clamps (below) to hold their collection bags and filters in place.
■ Dual positions. The Supermax collector, shown below, differs from the others in that its impeller sits in the same housing that supports the bags. But empty bolt holes in our unit leaked air until we covered them with tape or plugged them with bolts.
■ Portability. All the collectors have four swiveling casters for mobility, but the sturdy Powermatic, with bolt-on handles, proved easiest to move around the shop.
■ Remote control. Only the Powermatic comes with a remote control, letting you activate it without having to bend down and trigger the power switch. It’s an infrared model, so you have to point it directly at the machine to make it work. If you want a remote for the other models, you’ll have to buy an aftermarket remote control accessory ($50–$80) into which you plug your collector.
■ Noise. All the collectors measured between 73 and 82 decibels, below the level where NIOSH recommends you wear hearing protection. But with no other machine running, the constant droning of the collector might prove too annoying to just let it run when you’re in the shop.
■ Warranty. We always appreciate a lengthy warranty, but these dust collectors have few parts that can go bad (motor, impeller bearings). We’re not saying you should dismiss the warranty altogether, but don’t make it a huge part of your buying decision.
Put your money where the dust doesn’t blow
Our Top Value award goes to the Grizzly G1028Z2. Selling for $70 less than the Shop Fox, it produced results nearly as good.