Shop Vac Assessment

I gathered all of the shop vacs today and went through them, since several are not working.

Of the 5 Vacmasters, only 2 motors are working. All of the filters were in sad condition. Below is pretty much what they looked like. With filters like this, it is no wonder that the motors are dying. I combined hoses and containers to put together 2 working vacuums with hoses that can accept attachments, and cleaned out the filters. The good hose ends can attach directly to some tools, such as a DeWalt orbital sander.

Of the 3 non working, one had about 12 inches of cut off lamp cord. I tagged these three and put them under the loft. I didn’t want to take them straight to the dumpster, in case someone wants to go to the effort to rebuild.

There is a small Shop Vac which works. It needs filters. Stored to left of miter saw.

There is an old Husky vac, over by the miter saw. No hose, the motor runs, the filter was broken. I cleaned out that area under the counter and put it back, along with the little Shop Vac. Personally, I don’t think that the Husky is worth replacing the hose and filter on.

There is a small vac by the CNC with a cyclone collection attached. It works, but there is no hose leading into the cyclone, with which to clean up dust.

I went through the can of dust collector parts, by the table saw. Nothing useful for the other vacuums, but there are a couple of 3D printed manifolds, along with the other cyclones and PVC components. I remember those being mentioned in earlier dust collection conversations.

My suggestion is to trash the non working Vacmasters, and get rid of the Husky. Then get a couple more of the same model VacMaster. The Shop Vac is tiny, but it’s working and only needs cheap filters.

The small cyclone system needs a hose. I did not dig through the Shark station.

Here are links for the Vacmaster filters, including the exit filter, and new vacuums, if we want to replace any.

Vacmaster 4 Gallon Washable Cartridge Filter & Retainer, VFCF

Exhaust filter, VFHF

New Vacmaster vacuum:

ShopVac filter numbers
Foam sleeve 90585
Paper disc, 90107, 90137
There is no retainer ring for the paper filter.

Husky Vacuum Model number:
Filter: VF4000, VF5000, VF6000


Thanks for digging into this!

Are any of these vacs dedicated to a tool in particular, or are they all intended for general cleanup?

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Thank you so much. When I (eventually) get back to the shop, I want to work on general dust reduction throughout the space, and, well, that requires robust shop vac use.

Two other ideas

  • Add ‘how to clean the shop vac filters’ to the wood shop intro class
  • short video of that same lesson for existing members.

I think adding shop vacs to the intro is a great idea. Overall dust control is good. I’m going to look into adapters for the sanders that are there.

I don’t know if any were supposed to be dedicated. I haven’t been around that long. They all have different colored tape around the handles. Like the shop brushes that have station names, they have probably floated around to other places, if they were dedicated. I think that a vac by the miter saw, band saws and wood lathes would be great. Plus a few around the work tables. Not to mention the big shop vac at the CNC.

it would probably make sense to keep one in the machine shop too.

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Thanks for looking into this and documenting what you found. I agree that dirty filters are the quickest way to kill a shop vac. Thoughts on using either disposable or reusable pre filter bags on the shop vacs that don’t have a tornado dust collection system in front of them?

I love that idea @stepho! I think this is a great example of the kind of video we could add to our YouTube. There’s a really old account that no one knew who had access to it anymore, so we ended up making a fresh one (and shared the info in our LastPass account so it never gets lost again!) and right now the only thing on it is the video tour of the space. It would be great to also include videos like the one you suggested here.

I use bags on my home shop vac, but they are a consumable item. I don’t know how fast they would fill. But they would save the filters, and thereby save the motors.

Cyclones can be added, but you then need another container sitting alongside the vac. The large shop vac by the CNC is set up on a cart, along with a cyclone. 5 gallon buckets can be used, but again, it’s a project to get all of that integrated.

Maybe we should try vac bags for a few months and see how that works out.

I like the compact design of this one. Video We adapt our shops vacs to this design


I like that. The Dust Stoppers are very compact and already designed for 5 gallon buckets. The plywood could be cut on the CNC.

I have a shop vac at my shop that I need to modify. I will join the effort to make some. I think a cheap harbor freight furniture dolly will work for some of the shop vacs that don’t have wheels. I think the furniture dolly could be part of the base for the upper structure.

The tiny Shop Vac brand doesn’t have wheels, but it’s a 2.5 gallon unit. More of a table top unit.
The 2 VacMasters that are working have wheels.
The Husky isn’t worth investing in.

If we want the dust collectors, the stacked system you posted earlier might be the way to go. No matter what we do, if we go with dust collectors, we’ll need to do some mods. That cyclone is very short, which is good. But that plan would entail new vacuums, like the Rigid’s shown in the video.

We have a lot of experience with the Shop Vac separators here.

  1. The 5 gal hardware store buckets regularly implode. With a good vacuum, all it takes is sucking up a piece of cardboard or plywood for a few seconds to stop the flow and the bucket crushes itself and is destroyed. You learn not to do that, but with an open membership shop, so it happens pretty much all the time. I had much better success after finding empty 5gal pool chemical buckets, they’re MUCH thicker and more rigid. It is much harder to implode them. Another solution would be a vacuum breaker valve or an electronic vacuum shutoff. I did try a commercial breaker valve but it did not open enough to save the bucket.

  2. A large shop vac is unnecessary, as the point is to keep debris in the bucket, not inside the vac’s capacity at all. You’d think “but bigger shop vacs are more powerful”. They’re not. There’s little consistency in how high-flow the vac is vs the size. “Well look for the label with the most X hp on it”: The way they measure HP is literally fake. An outlet is only capable of providing about 2hp. The “5 peak HP” came from basically the idea that if you jammed the rotor so the motor can’t turn and put 120VAC on it, how much peak current would it draw in the 2 seconds before the windings burned up? It’s a ghost standard- even the best mfgs continue to use these made-up inflated numbers because people expect it.
    In reality, almost all vacuums draw 1.5hp-1.9hp full open. However, the actual flow varies a LOT between units, and there’s no correlation between size (or nameplate “peak HP”). The champ was the Shop-Vac 5870400 (the small green one). It has one of the highest flows of any shop vac made, of any size.
    The notable exception is the blue VacMaster, which is a 7 amp (~1HP) vac. It is less flow than most shop vacs, but the current draw is so low it usually won’t pop breakers when combined with something else on the same circuit. It’s also quiet. These were intended to be used especially on hand tools with dust collector ports. It’s plenty more suction than they need, and it’s pretty essential for the workbench islands because they only have one 15A circuit on the ceiling drops so trying to power a hand sander and any other shop vac will generally overload the circuit.

Anyhow, regarding the separators-
First it’s very important to make a distinction between what the specific scenario of what we’re trying to vacuum up is. Wood dust comes in all sorts of particle sizes, and each presents a very different problem. For example, the planer and jointer make chips. They can be a lot of bulk, and mass, but they’re not actually dust, generally. There’s not much to go airborne and it can’t clog a vacuum filter even if it fills up the container. Sanding generates very small particle sizes, and the material’s density of what’s being sanded matters too. Cutting in the miter saw or table saw is highly variable. Just feeding the table saw slower will produce much finer (more problematic) particle sizes on the same job! And there’s also a “chunk” problem with the table saw, miter saw, or floor vac to consider. Chunks can obviously jam vacuum systems, but can be addressed in different ways, that’s not too hard.

Pretty much all separators are nearly 100% effective at removing bulk chips like that. But, as you change the task to fine particle sizes of dust (the real problem), the picture changes quite a bit. There’s an additional complexity too- re-entrainment is a significant problem. That is, what was initially separated out ends up in the can, but the way airflow agitates the can, every minute it’s left on, the agitation keeps a storm of dust suspended inside the can, and some of that ends up slowly flowing out of the separator, towards the vacuum. Thus the vacuum and its filter are being hit with fine dust that bypassed the separator all the time it’s running, even if there’s no new dust coming in.

All separators become less effective with smaller, lighter particles. The effectiveness for any sort of separation device in both initial capture and re-entrainment leakage will vary quite a bit with flow rate too. The overall effectiveness can actually get better with a lower flow rate through the vacuum (this is one reason the little blue VacMasters were installed in the shop).

The can-top stuff is low profile, and completely effective at separating chips. However, chips were never the problem for the vac filters, that’s all about keeping fine dust under control. They’re often not the best for fine dust, especially on the re-entrainment leakage front.

The next-gen cyclones (“Dust deputy” type is NOT this) are vastly better at this critical, difficult fine dust problem. The height of any sort of cyclone is a prob for portable carts, you don’t want to tip it over by pulling on a top-mounted hose, but you can plumb the inlet down to a lower attachment point. But, multiple smaller cyclones can greatly reduce the problem. Also the re-entrainment leakage problem can go away because the rotation of flow underneath each cyclone ends up interfering with each other, resulting in still air in the can that does not re-entrain. They’re somewhat more difficult to see how to plumb up, and of course they can’t take big chunks of wood that won’t fit in the inlet. The chunk/strings/etc problem is usually addressed in other ways (grill or whatever, depends on the scenario).

The example that was in that video I could see being somewhat problematic due to center of gravity with the potential of tipping over. Not to mention once it is full it would be a bit more difficult to lift the entire bucket up and out to empty. When i had a woodshop setup in my garage at an old apartment I actually found a perfectly good Large Rigid Vac at the good will outlets for $5 I believe. I needed something for it to move around on and connect to the cyclone i had purchased so i ended up building this cart for it and it still resides on that same cart to this day. I think i still have the plans for it somewhere if someone would like them.

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We’ve had a similar cart at the space for many years, but the vac on it is huge and pretty poor for suction. The cart’s bulkier than it needs to be, it rarely gets used. The Oneida can imploded right off the bat, and its replacement imploded, and then the one after that, until I found a pool chlorine bucket. That’s the Dust Deputy cyclone type that is so outdated. And like I say there’s no reason there should be a 14 gal shop vac on it, since material is not supposed to go into the vac at all. The point is to get it in the bucket which is only 5 gal there.

The big question I had to wonder about- can you put a cyclone on its side, or at least at an angle? At first that sounds dumb, and that may indeed be the case. But the way the cyclonic action works on a good one, the orientation may not matter much. I could even see a possible case where it could work better than vertical (complicated to explain how that could be). It could be a very convenient game-changer form factor if it works- but, I’m just not sure it would work.

This is was a setup that I picked from someone recently. I like to compact design. The bucket seems heavier duty than a regular 5 gallon bucket. The wood plate is for a set of swivel wheels

Maybe this is a dumb question, but what’s the purpose of the cyclone pre-filter? Is the goal to just reduce loading of the shop vac filter medium?

You are correct. The cyclone lets the filter flow for much longer.