By Martin Harris.

Dust Collector Bins, Buckets, and Liners

For a shop vac cyclone, use a 5 gallon bucket with a wall at least 90 mils thick, or nest two thinner buckets together. For a Super Dust Deputy on a dust collector, use the fiber drum from the kit or a steel drum. For liners, Oneida Air Systems sells 1.5 mil bags for 9 to 17 gallon bins, 2 mil bags for 22 gallon bins, and 3 mil bags for 30 to 55 gallon bins. A liner under a cyclone has to be held open, or it gets sucked up into the cyclone.

A mil is one thousandth of an inch. A 90 mil bucket wall is 0.09 in. thick, and a 3 mil liner is 0.003 in. thick. This guide covers bag and bin sizes, liner thickness, containers for separators, how to keep a bin from collapsing, and how to empty one without breathing a cloud of dust.

Lower bags versus separator bins

A single-stage dust collector, the common bag style, pulls chips and dust through its fan and blows them into a lower bag. The upper bag or cartridge filters the air on its way out. On these machines the lower bag is the bin. Clear plastic lower bags let you see the fill level at a glance. My guide to the best dust collector bags covers filter bags and micron ratings.

A two-stage setup puts a separator, such as a cyclone or a Thien baffle, in front of the fan. Dust falls out of the air into a rigid bin below the separator: a bucket, a drum, or the collector's own bin. The difference that matters is pressure. A lower bag sits after the fan, where air pushes outward on it. A separator bin sits before the fan, where suction pulls its walls inward. That is why wall strength matters so much for separator bins.

Bin sizes by setup

Sources: Oneida Air Systems product pages, drum kit listings, liner bag listings, and Dust Deputy FAQ; J. Phil Thien, jpthien.com.

Bigger is only better up to a point. Oneida says the larger the container, the sturdier its walls need to be. A big bin also gets heavy when full, and you still have to lift it. In a one or two car garage, I would rather empty a smaller bin more often than wrestle a full 55 gallon drum. If you are choosing a cyclone and bin together, my Dust Deputy vs Super Dust Deputy guide matches each cyclone size to its bin.

Liner thickness

Source: Oneida Air Systems clear plastic dust bin liner listings. Oneida's full liner line runs from 1.5 to 4 mil.

Thicker liners go with bigger bins. A bigger bin holds more chips, and Oneida says the heavier thickness resists tears from wood chips and other sharp debris. A torn liner dumps dust into the bottom of the bin and spills it when you lift the bag out.

Match the liner to the bin volume, and to its shape. Oneida sells both box-shaped and round liners, and a liner that fits the bin sits flatter against the walls. Clear liners also let you see how full the bin is without opening it.

Keeping a liner in place under a cyclone

Under a cyclone, the bin is under suction the whole time the collector runs. An empty liner is light and flexible, and that suction pulls it up toward the cyclone opening. Oneida says a liner in a cyclone bin has to be held open, or it will be sucked up into the cyclone.

Oneida's answer is a rigid plastic sleeve that sits in the bin and holds the liner open. Oneida says the sleeve keeps its round shape under the constant suction of the collector. The sleeve gives the thin plastic a stiff wall to rest against, so the liner stays down in the bin while dust fills it.

On a 5 gallon shop vac bucket, a liner is optional, since the bucket is easy to lift and dump. If you do line one, check that the liner doesn't bunch up under the lid gasket and break the seal.

Stopping a bin from collapsing

A bin collapses when the suction inside is stronger than its walls. Shop vacs are the biggest risk. Oneida says a shop vac pulls more than 60 inches of water column (in. w.c.), a measure of suction pressure. Systems built for its Super Dust Deputy run below 10 in. w.c. So a bucket that works fine under a collector can fold up under a vac.

• Use a thick bucket. Oneida says a 5 gallon bucket needs at least a 90 mil wall, and that big box store buckets are too thin. Oneida's own clear 5 gallon bucket for the Dust Deputy is sold as collapse-proof, and it comes with the Oneida Dust Deputy Deluxe kit.
• Nest two buckets. Oneida says two stacked thin buckets hold up, because the outer one stops the inner one from bulging out as it bends.
• Retire old buckets. Oneida lists old, damaged, and thin-walled buckets as the ones that fail.
• Keep fiber drums off shop vacs. Oneida says fiber drums are not typically suited to pressures above 80 in. w.c. and may collapse unless reinforced.
• Use steel for big bins. Oneida's 35 and 55 gallon drum kits for the Super Dust Deputy are galvanized steel.

The Wood Whisperer ran into this in his cyclone separator shootout, where one unit's collection bucket collapsed under suction. For three shop vac builds that include a two-bucket stack, see my DIY dust separator guide.

Knowing when to empty

Empty the bin before the pile reaches the separator. With a Thien baffle, Phil Thien says you can fill to within 3 in. of the top of the can, which is the bottom of the baffle. With a cyclone, empty before the pile gets close to the cyclone's bottom opening. Past that point, the spinning air picks dust back up and sends it to your filter.

Clear containers make this easy. Oneida's shop vac kits use a clear bucket, and many single-stage collectors use clear lower bags. If your bin is opaque, check it at the end of each session until you learn how fast your tools fill it. A planer fills a bin far faster than a sander does.

Emptying safely

Emptying a bin throws the finest dust in your shop back into the air. NIOSH recommends keeping wood dust exposure under 1 milligram per cubic meter of air over a workday, which is a very small amount of dust. OSHA also notes that wood dust is combustible when enough of it is in the air. Follow these steps every time.

1. Shut it down. Turn off the collector or vac and let the fan stop before you open the bin.
2. Put on a respirator. Wear a NIOSH-approved respirator, such as a well-fitted N95 or a half mask with P100 filters. My woodworking respirator guide covers which ones fit and seal well.
3. Close the liner before you lift. Gather the top of the liner, twist it shut, and tie it while it is still in the bin. Then lift it out.
4. Dump outside when you can. If you pour a bucket, pour it low and slow into a trash bag, with the bucket rim down inside the bag.
5. Lift with care. A full bin gets heavy. Empty it before it is more than you can lift comfortably.
6. Never blow dust off with compressed air. OSHA's woodworking guidance says blowing dust with compressed air creates the kind of dust cloud that is the greatest explosion hazard. Clean up spills with a vacuum.
7. Keep finishing rags out of the bin. Rags soaked with oil finishes can heat up and catch fire as they dry, and a bin of dry wood dust is good fuel. Lay oily rags flat outside to dry, or store them in a sealed metal can.
8. Clean the seal. Wipe dust off the lid gasket and the bin rim before you close it, so the lid seals tight again.

Where to go next

For the separators these bins sit under, see my best dust separator roundup. For how bins, bags, and filters fit into a whole garage system, read my complete guide to small shop dust collection.

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