Shop-Vac

A Shop-Vac is the vac you grab for the messes a household vacuum would choke on: shop chips, job-site debris, drywall dust and water on the basement floor. The name is so common that people call every wet/dry vac a shop vac, and there’s a reason for that. This is the company that built the category, and it still sells the whole setup under one name: the vac, the cartridge filter, the foam sleeve for water, the bags and the hoses.

Shop-Vac Corporation is headquartered in Williamsport, Pennsylvania. Martin Miller founded it in 1953 because he wanted to replace the broom and dustpan in his workshop with a vacuum that could pick up wood and metal chips too big for a household machine. The Miller family ran it for more than 60 years, and Hangzhou GreatStar Industrial owns it now. It’s best known for wet/dry vacs and also makes motors, air movers, fans and blowers.

Picking the size

Size the tank to the worst mess you expect, not the average one. A 6-gallon vac is the one for the truck, the car and the bench; it stores on a shelf and comes out for a spill without any fuss. The 10- and 12-gallon vacs are the right size for most garages and basements, big enough to hold a day of shop chips or a good puddle and still easy to roll around. The 16-gallon is the job-site vac and the one for a real water job. When spring runoff comes up through a Montana basement floor or a sump pump quits in the middle of it, a small tank fills in a few minutes and you spend the afternoon hauling it to the drain.

Water weighs about 8.3 pounds a gallon, so a full 12-gallon tank is close to 100 pounds. Empty the big ones before they’re full, not after.

Switching from dry to wet

Every Shop-Vac sold as a wet/dry vac does both jobs, and the switch happens at the filter. Unplug the vac, pull the paper cartridge and any bag, dump the dry debris, and slide the foam sleeve over the filter cage. The most common mistake is vacuuming water with the paper cartridge still on: it soaks through, sags and goes in the trash. After a wet job, dry the tank and the foam before you go back to sawdust, or the dust turns to mud inside the tank.

Filters and bags for dry pickup

Run a cartridge filter for anything dry. Without one, fine dust goes straight through the motor and out the exhaust into the room. Even with the cartridge on, the finest dust is the hardest on it, and drywall dust is the worst of all: it packs the pleats, the motor bogs and suction drops. The fix is a disposable filter bag in front of the cartridge. The bag catches the fine dust, the pleats stay open, and emptying the vac means lifting out a bag instead of dumping a cloud of dust in the driveway. Shop-Vac makes two kinds: plain collection bags that catch the debris, and filter bags built to hold fine dust like drywall sanding. Both come sized to the tank, so buy the bag for your vac and pull it out before any wet job.

A foam pre-filter over the cartridge is the cheap insurance for a woodshop. It stops the coarse dust and chips before they reach the pleats, so the cartridge lasts longer between cleanings. In a garage shop that stays shut up most of the winter, that keeps the cartridge open and the suction strong through months of sawdust.

Matching a filter to your vac

Bags go by tank size, small, medium or large, and the cartridge filter and foam sleeve go by the vac’s filter cage. Cartridges come in more than one size, including a 6-1/2-inch paper cartridge, so check the size against the cage. The model number settles all of it. It’s on the label with the UL listing and the electrical specs, normally on the back of the vac. Take a picture of it before you come in, and the filter, foam sleeve and bag all match on the first try.

Hoses and attachments

Shop-Vac sizes its hoses and attachments by diameter, 1-1/4, 1-1/2, 1-7/8 and 2-1/2 inches, and a tool fits a hose of its own diameter. The 8-foot, 1-1/4-inch hose is the detail setup for cars, corners and the back of a workbench, with the 9-inch crevice tool for between the seats and a brush for dusting off tools and window sills. The 12-inch combo floor nozzle is the one for a wet basement floor or a garage full of sawdust. After a wet job, drain the hose and hang it in loose loops on a hook, because tight coils kink and hoses split at the kinks.

Shop-Vac at a glance

Item	Size	Use
Wet/dry vac	6 gallons	Truck, car, bench and small spills
Wet/dry vac	10 and 12 gallons	Garage, basement water and shop chips
Wet/dry vac	16 gallons	Job-site debris and big water jobs
Paper cartridge filter	Matched to the vac’s filter cage, including a 6-1/2 in. size	Dry pickup
Foam filter sleeve	Matched to the vac’s model	Wet pickup
Foam pre-filter	Fits over the cartridge	Coarse dust, longer cartridge life
Collection bags	Sized to the tank	Everyday dry debris
Disposable filter bags	Sized to the tank	Fine dust and drywall dust in front of the cartridge
Hose	8 ft. x 1-1/4 in.	Cars, corners and detail work

Frequently Asked Questions

Are all Shop-Vacs wet/dry vacs?

A Shop-Vac sold as a wet/dry vac picks up water with the same motor it uses on sawdust, and a float inside the filter cage rises and shuts off the airflow when the tank is full. The brand also sells fans, air movers and blowers, so check that the box says wet/dry before you count on it for water.

How do you use a Shop-Vac to pick up water?

Take the paper cartridge and any bag out, put the foam sleeve on, and plug the vac into a GFCI outlet with the cord connection up off the wet floor. When the tank fills, the float cuts off suction and the motor’s pitch goes up. That means it’s time to shut it off and empty the tank, not that the motor is failing. Never pick up gasoline, solvents or anything else flammable.

Does a Shop-Vac need a filter for wet pickup?

Yes. The foam sleeve over the cage is the wet filter, and it keeps splash, grit and hair off the float and the motor. After a dirty-water job, rinse the foam, squeeze it out and hang it to air-dry. Replace it when it’s torn or smells of mildew.

Which filter fits my Shop-Vac?

Start with the model number on the label on the back of the vac. Match the cartridge filter for dry pickup and the foam sleeve for wet pickup to that model, and add the small, medium or large bag that fits your tank if you pick up fine dust.

How do you put a filter bag in a Shop-Vac?

Unplug the vac, lift the lid and slide the bag’s collar over the inlet inside the tank until it fits snug. Open the bag out so it isn’t bunched against the cage, and leave the cartridge filter on behind it. Throw the whole bag away once suction drops or the bag is close to full, since the bags aren’t made to be emptied and reused.

Is Shop-Vac still in business?

Yes. Shop-Vac shut down its Williamsport operation in September 2020 after a sale fell through, and in December 2020 GreatStar Tools USA bought the company and reopened it. Williamsport is still its headquarters and main distribution warehouse, and genuine Shop-Vac filters, bags and parts are still made.

How do you clean a Shop-Vac cartridge filter?

Take it outside and tap the end cap against the inside of a trash can to knock the dust loose, or blow low-pressure air out through the pleats from the inside. Rinse a cartridge only if its label says it’s washable, and let it dry completely before it goes back on for dry pickup. Replace any filter with torn pleats or a split seam, because dust goes straight through the tear.