Duct-tape air scrubber

[Jeff Dege]

I'm just getting started in woodworking, and hence am just getting started in putting a shop together. I am currently about 3/4 of the way through building my first bench.

I'm in a basement, and dust collection is already a problem. I've read with interest the threads here on dust collection systems, cyclones, and various air scrubbers. I may, someday, build or buy all of those. But three months ago I didn't have a circular saw, and I still don't have a bench. So the question is what can I do, with what I have.

I connect the shop vac to any tool that has a vacuum port, of course. And I vacuum up what's dropped and sprayed immediately, before it can be trapped. But that's not been catching the really fine dust, that doesn't settle for a while. For that, it seems I need an air scrubber. But I can't see putting time into building that until I've finished my bench.

So the question becomes, what can I do in fifteen minutes with a furnace filter and a roll of duct tape? It turned out to work surprisingly well. I plugged the shop vac in backwards and blew the sawdust off all the various surfaces while the gizmo was running, and it caught a large fraction of it before it settled down. Grabbed a bunch of the assorted crud and spiderwebs, too. All-in-all I'm quite satisfied.



(Construction details at: A Guy's Guide to Dusting).

[Leo Graywacz]

What are you using to power the air flow?

[Jeff Dege]

It's an "industrial" air blower I found down at the borg. Basically, it's just a squirrel-cage fan.

[Dewey Torres]

An el cheap o box fan works well also and there are some threads here with a few slick set ups.

[Jeff Dege]

An el cheap o box fan works well also

I had one of those, already, using a hand-me-down box fan that has to be at least 40 years old. I figured that with my planned shop-vac dusting project, I needed more air-flow. Judging by what's sticking to the filters, the squirrel cage fan is doing a better job. (Though it's certainly possible than a less arthritic box fan would do as well.)

[Bob Rufener]

Jeff, I did a similar thing a number of years ago. I had a dual squirrel cage blower from a range hood that I replaced in our kitchen. One day, I decided to build a box around it. I designed it so that I could attach it to the ceiling of my basement shop. I use a 20 x 20 furnace filter on the bottom and a 12 x 20 on two of the sides. The blower is inside of the box and exits out of one of the ends. I left the other end solid to provide support. It works well and picks up a lot of airborn dust. Every so often, I remove the filters, take them outside, and blow them clean with my air compressor. It may not be as pretty as commercial units but it does the job.

[Jeff Dege]

I've seen some very fancy-looking boxes, in threads in the forum. But I'm still a couple of weeks away from having my bench finished, and according to my POSSLQ, the dust couldn't wait. Hence, cardboard boxes and duct tape. I expect I'll replace it, eventually, with something more durable.

[Myk Rian]

You need more than 1 filter. 3 or 4 filters will give a huge increase in airflow, thus cleaning the air much quicker.
Make sure you are drawing the air through the filters, instead of pushing it through.

[Brad Bartley]

It's like the make-shift CO2 scrubber in Apollo 13.

[David Hostetler]

I've got one of those box fan / allergen filter "air scrubbers". It works reasonably well. Not a high flowing high powered unit by any means. I would LOVE to see what that squirrel cage fan could do with a couple of large surface area allergen filters on some sort of plenum... OP, you definately are on the right track for the cheap shop method of air scrubbing... I like it.

[Jeff Dege]

I would LOVE to see what that squirrel cage fan could do with a couple of large surface area allergen filters on some sort of plenum...

Like I said earlier, this seems to be working better than the box-fan I'd tried before. I think the difference is that with a box fan you get more air leakage from the back, around the corners of the box - which means less air moving through the filter.

[David Hostetler]

Like I said earlier, this seems to be working better than the box-fan I'd tried before. I think the difference is that with a box fan you get more air leakage from the back, around the corners of the box - which means less air moving through the filter.

I should snap some pics of mine. I taped all the way around the filter, including the gaps in the stamped tin housing, The only air getting in is going in through the filter, the only air going out is through the front of the fan...

Still not enough CFM from the rig to make me a happy camper...

[Jeff Dege]

In my square box fan, where no matter how well you seal up the back grill, air can come in through the corners of the front.

[Chip Lindley]

LOL Jeff! From the Title of your topic, I could only assume you were hanging myriad strips of duct tape everywhere in your shop to catch dust (like fly paper)! I like your Real solution Mucho Betta!

[Jerry Murray]

excellent idea for the airflow and filter. I have to go to borg this weekend and will pick up an extra "allergan" filter for my box fan.