Proof of Concept – Cheap And Easy Downdraft Table

During (another) recent pre-martial-law episode of basement workshop archaeology at my daughter’s house I rediscovered a successful “proof of concept” prototype, a phrase I learned from my pal Ripplin’ John and have come to use with great regularity.  I cannot even recall the particular project at this point, but only vaguely remember that I needed to do a lot of sanding in the winter, hence it would be inside.  I needed a dust control scheme so efficient that Mrs. Barn would not even notice a speck of the dust upstairs, the basement steps ending/beginning immediately off the kitchen.

I had designed a downdraft table for dust control during upholstery stripping decades before and it worked wonderfully for the furniture conservation group I designed it for.  In the intervening years downdraft sanding tables had become more common, but I did not have the space or need for one of these big units, 24″ x 36″ or thereabouts was all I needed.  Pus, it had to be a benchtop unit given the restricted footprint of my basement workshop.

Being someone who rarely throws away anything that could theoretically become useful in the future I had almost everything I needed to build the unit.  The only thing I needed to buy was a 24″ 48″ piece of pegboard from the home improvement center.

I had some nice scraps of 1/2″ tempered foam core sheet and made the box walls from them, sawing them on the table saw. I glued them together into the frame using hot melt glue.  Double- or triple-wall carboard would have worked just as well.  (One of the reasons I did not use wood walls was my desire for the unit to be ultra light weight; wood would have increased the weight several fold.)

I knew that my small unit, unlike the large downdraft tables, would need to have the air drawn from one end rather than from underneath so the internal air-flow volume had to be tapered, fattest at the end where the fitting was inserted to draw the air and very shallow at the other end.  This tapered plenum provided a more equal air flow over (and through) the work surface of the unit, much like reduced/increased ducting controls the evenness of air pressure within air conditioning and heating systems.  I found in practice the unit performed admirably in this regard.

The taper was achieved by gluing parallel strips of wood to the insides of the box fame, then stapling on a bottom of corrugated plastic sheet.  Again, all it had to do was direct air and not support anything but itself.

For the working surface of the unit I simply cut and glued on a piece of pegboard, with only one cross rib in the center since the dimensions preluded any severe sagging given the pieces I was working on.

When I first set up my tiny basement workshop I purchased a larger-than-necessary cyclone collector, a machine that served me magnificently for all those years and remains the cornerstone of shop cleaning in the barn to this day.  I cut a hole in the fat end of the plenum to insert the 3-inch hose fitting from the collector and the unit was done.

I am really glad I rediscovered this accessory and have kept it in my barn workshop since I do everything I can there to keep airborne dust to a minimum.  I was recently using it to do some sanding and it still works great.

All it took those many years ago was a bunch of scrap materials and about an hour’s time to make.  It was the perfect solution to the problem I had, and if you have an indoor space with the same constraints you might give it a try.