Canadian Woodworking
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10 tips to improve your shop dust collection

Author: David Bedrosian
Photos: David Bedrosian
Published: June 2024
Dust collection
Dust collection

Dust, one of the most common workshop hazards, is sometimes nearly impossible to see. Learn how to better equip your workshop to tame dangerous wood dust.

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How effective is the dust collection in your shop? Do you see airborne dust accumulate on your machines? I’ve spent several years optimizing my dust collection setup and here are my top 10 tips to help if you’re setting up a new system or wanting to improve the performance of your existing system.

1. Two Stages are Better than One

Many woodworkers, myself included, start out with a sin­gle-stage dust collector since they’re the least expensive and the footprint is relatively small. Unfortunately, these units have some drawbacks. All the chips, shavings and dust pass through the blower and need to be trapped by the filter. As dust builds up on the inside of the filter, air doesn’t pass through as easily and the suction is reduced. As well, any small cutoffs, screws and nails that may get sucked up come in direct contact with the impeller which can cause damage and may even be a fire hazard.

A two-stage dust collector adds a pre-separator, most often a cyclone, that separates the majority of what gets sucked up, leaving only the finest dust to pass by the impeller where it gets trapped by the filter. Less dust to the filter means the suction remains high and the filter doesn’t have to be cleaned as often. If you currently own a single-stage unit, you can purchase a cyclone separator to create your own two-stage collector. The suction will be reduced slightly but the overall performance will be improved.

Add a Garbage Can
Add a Garbage Can – Although not as good as adding a cyclone separator, this garbage can-style lid improves the performance of a single-stage dust collector. Most of the larger debris falls into the garbage can rather than getting pulled past the impeller.

2. Maximize Filter Area

My first dust collector in the early ’90s had a thin cloth bag for a filter which let all but the largest particles through. The walls adjacent to the collector were always coated in a layer of fine dust. My dust collector was effectively a dust pump pollut­ing the air in my shop. Filters have improved considerably since then, with the most effective ones trapping the smallest wood dust particles. Over time, these particles build up on the inside of the filter making it harder for the air to pass through, which reduces the suction. Filters with more surface area take longer to clog, which lead to the development of pleated filters that have more than 20 times the area of a similarly sized bag filter. After-market pleated filters are available for most dust collectors. They’re more expensive than bag filters but they last a long time and offer a sig­nificant performance improvement.

Double the Surface Area
Double the Surface Area – Bedrosian made a custom plenum so he could use a pair of pleated filters on his dust collector. This gives about 500 square feet of surface area, which allows him to get by with a 2HP cyclone. It provides a tremendous amount of suction throughout the shop.
Make It Airtight
Make It Airtight – The dust bin and the connection to the bottom of the cyclone must be airtight. Even a small leak will reduce the efficiency and send far more dust to the filter which will quickly clog it, thus reducing the suction. Bedrosian uses a clear garbage bag and has a plastic window in his dust bin so he knows when it needs emptying. Don’t make the mistake of overfilling your dust bin or it will be a lot of work to clean your filter.

3. Clean Your Filter

If you notice your dust collector is losing some of its suction, it could be that your filter is getting clogged with fine dust particles. This is to be expected, and is an indicator that it’s time to clean your filter. I do this two or three times per year, based on the read­ing on my water manometer. I do it outside, typically on a windy day, using a combination of my leaf blower and my compressor set to 60psi to avoid damaging the filter material. Be sure to wear a dust mask to avoid inhaling any of the dust.

Coloured Water
Coloured Water – A simple water manometer can be used to indicate when your filter needs cleaning. It measures the pressure inside the filter, which goes up as the filter gets clogged. This pressure pushes down on the water in the tubing leading to a height difference on the two sides. Bedrosian cleans his filters when the height difference with a 6″ blast gate open is more than 1.5″ (it’s reading about 1″ in the photo). After cleaning, the height difference is very close to 0, meaning there is almost no resistance to the air flowing through the filters and Bedrosian is getting maximum performance. There are several YouTube videos describing how to make a water manometer for a dust collector. Bedrosian also has a temperature sensor and an ammeter so he can monitor the dust collector motor.
Count the Dust
Count the Dust – Bedrosian invested in a particle counter so he can monitor the air quality in his shop. Operations such as hand sanding, routing and even sweeping the floor send a lot of dust into the air, causing the particle count to rise. An air cleaner helps to capture the airborne dust, but it takes time, so Bedrosian wears a dust mask until the count comes down.

4. Maximize Duct Size

The size and type of ductwork you choose will impact the perfor­mance of your dust collection system. In general, larger diameter pipes with a smooth inner wall work best.

Some dust collectors come with a reducer at the inlet so you can connect multiple 4″ pipes to different machines. You’ll get much more airflow if you eliminate the reducer and use a larger pipe to match the size of the inlet. My collector has a 7″ inlet so I used that size pipe for the main run and I branch off from there to connect to each machine using a blast gate to control the airflow.

My engineering background was helpful when designing my sys­tem but it isn’t a requirement. Online resources are available and some manufacturers offer design services for a fee or even for free.

5. Enlarge 4" Dust Ports

Most woodworking machines come with a 4″ port, which is acceptable for smaller machines. On larger machines like planers and jointers, this small size will limit the ability to collect all the chips and dust that are generated. You’ll get better airflow if you enlarge the port to match the size of your mainline up to a maximum of 6″. I recently added an edge sander to my shop, and with heavy sand­ing there’s not enough suction with the 4″ port to capture all the dust. I plan to make a new dust shroud with a 6″ opening that will more than double the airflow, making it much harder for dust to escape. If you can’t change the port size, it’s best to run a larger diameter pipe to the machine and place the reducer there.

Go Big
Go Big – Bedrosian’s 14″ planer generates a lot of chips, so he made this custom dust hood and connects it to a 6″ pipe for maximum airflow. Most similar planers come with a 4″ port which is too small for adequate collection.

6. Split Some Connections

If you have a 5″ or larger mainline duct, you may want to create split connections to some machines to improve collection. For example, I have a 6″ pipe running to my large bandsaw where it splits into a 5″ hose running to the base of the saw and a 3″ hose next to the blade. Even though the 3″ hose is relatively small for dust collection, it improves the dust collection noticeably over just using the 5″ connection at the bottom of the saw.

Split Connections
Split Connections – Bedrosian uses split connections for some machines, including his router table. A 5″ pipe coming off the mainline splits off to a 4″ hose connected to the back of the table and a 3″ hose connected to the opening in the fence. This combination offers better dust collection than a single connection.

7. Leave It Running

Repeatedly turning on and off a single-phase dust collector places a lot of strain on the motor. Unlike a jointer, planer or table saw, which powers up without a load, a dust collector is under a heavy load when it’s switched on. I’ve got an ammeter on my dust collec­tor and the startup current is about five times more than when the collector is running. This generates stress and heat inside the motor, which accumulates with repeated starts in a short time. In my shop, I leave my dust collector running if I plan to use it again within the next 15 minutes.

Another advantage to leaving your collector running is that it acts as an air cleaner. With a 6″ blast gate open, it takes time, but my particle counter shows an improvement in air quality as the dust collector draws in dusty air and blows out clean air through the filters.

Simple Boom Arm
Simple Boom Arm – Bedrosian used a piece of electrical EMT pipe to create this boom arm for his shop vac. It’s secured with a single bolt, which allows it to rotate above his bench. Two different power cords are plugged into his shop vac so it turns on automatically when using a connected tool.

8. Augment with a Shop Vac

Dust collectors are meant to move a lot of air through a large pipe but they don’t work well when connected to a small opening found on a sander or a handheld router. For those cases, a shop vac is a better choice. More expensive shop vacs are quieter and often have filter bags that are easily changed, but lower-priced units can be just as effective. If your shop vac doesn’t have a pleated filter, I recommend adding one to trap more of the fine dust so it doesn’t get blown into the air. Like dust collectors, those pleated filters will benefit from an occasional cleaning.

9. Add an Air Cleaner

Even the most powerful dust collector can’t capture all the dust generated in a shop. Hand-held routing, hand sanding, turning at the lathe and many other operations send a lot of dust into the air. As previously mentioned, your dust collector makes a good air cleaner, but you can also buy or make a dedicated unit that can stay running even when you leave the shop. I have two homemade air cleaners in my shop – one above my lathe and the other in the middle of my shop. They’re effective even though they take several hours to clear the dust, as confirmed by my particle counter.

Clean the Ai
Clean the Air – Bedrosian made this air cleaner that hangs above his lathe. An old furnace blower draws air through a pleated furnace filter that captures most of the dust and debris. Any dust that gets through is trapped by the large pleated filter that’s on the output side of the blower. A timer switch keeps the cleaner running for up to four hours after it has been turned on.
Sanding Hood
Sanding Hood – Bedrosian added a custom dust hood to his disk sander. He started with a 10″ wide dust hood and cut away part of one face so it fit over the sanding shroud. He added angle brackets with rare earth magnets to secure the hood to the shroud. It’s easily removed or repositioned as needed.
Repurpose a Task Lamp
Repurpose a Task Lamp – A length of flexible hose attached to an old articulating lamp works great when you need a moveable dust port. This one is at Bedrosian’s lathe and it could also be used at a drill press or on a workbench.

10. Wear a Dust Mask

A properly fitting dust mask should be part of everyone’s wood­shop dust control plan. Any dust that’s not captured at the source will become airborne, and even with a good air cleaner, it will remain in the air for some time. Wearing a dust mask is an inexpensive and effective way to protect your lungs. Consider getting a few and placing them in different locations in your shop so one is always handy when it’s needed.


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